DE102012206049A1 - Fabricating radiation cured structure, useful in fuel cell, comprises providing first and second radiation sensitive materials and placing a mask between them, exposing the materials to radiation beams, and forming constructs in materials - Google Patents

Abstract

Fabricating radiation cured structure, comprises: providing (104) first radiation sensitive material; providing (106) second radiation sensitive material adjacent to first radiation sensitive material; placing (108) a mask between a radiation source and the first and second radiation sensitive materials; exposing (110) the first and second radiation sensitive materials to many radiation beams; and forming (112) at least a first and second constructs respectively in the first and second radiation sensitive materials. Fabricating a radiation cured structure, comprises: providing (104) a first radiation sensitive material having a first sensitivity; providing (106) a second radiation sensitive material adjacent to the first radiation sensitive material, where the second radiation sensitive material has the first sensitivity and a second sensitivity different from the first sensitivity; placing (108) at least one mask between at least one radiation source and the first and second radiation sensitive materials, where the mask has many radiation transparent apertures; exposing (110) the first and second radiation sensitive materials to many radiation beams through the radiation transparent apertures in the mask; and forming (112) at least a first and second constructs respectively in the first and second radiation sensitive materials, where the first construct and the second construct cooperates to form the radiation cured structure.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. Patent Application Serial No. 12 / 339,308, filed December 19, 2008. The entire disclosure of the aforementioned patent application is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention relates to radiation cured materials, and more particularly to a process for producing radiation cured materials having complex structures.

BACKGROUND OF THE INVENTION

Radiation-cured microstructures are of Jacobsen et al. in Acta Materialia 55, (2007), pages 6724 to 6733 in "Compression behavior of micro-scale truss structures from self-propagating polymer waveguides." the entire disclosure of which is hereby incorporated by reference. A process and system for producing polymer materials having ordered microstructures is disclosed by Jacobsen in US Pat U.S. Patent No. 7,382,959 , the entire disclosure of which is hereby incorporated by reference. The system includes at least one collimated light source selected to produce a collimated light beam; a reservoir having a photomonomer adapted to polymerize through the collimated light beam and a mask having at least one aperture disposed between the at least one collimated light source and the reservoir. The at least one aperture is adapted to guide a portion of the collimated light beam into the photomonomer to form the at least one polymeric waveguide through a portion of a volume of the photomonomer. Jacobsen will be in the US Patent Application No. 11 / 801,908 the entire disclosure of which is hereby incorporated by reference, further describes microcarrier materials made by the method and system. A polymer material that is exposed to radiation and becomes self-focusing or self-trapping for light by the formation of polymer waveguides is also described by Kewitsch et al. by doing U.S. Patent No. 6,274,288 the entire disclosure of which is hereby incorporated by reference.

Products made by a two-coat photoresist process are described, for example, by Orvek et al. by doing U.S. Patent No. 4,770,739 the entire disclosure of which is hereby incorporated by reference. Over the top surface of a body, a first photoresist material is arranged, which is sensitive to near UV light or violet light. Above the first photoresist material, a second photoresist material is arranged, which is sensitive to deep UV light. The second photoresist material is exposed to patterned deep UV light illumination and exposed areas are then removed. The first photoresist material is illuminated by a flood or blanket exposure of near UV or violet light. Thereby, the two-layer photoresist product is formed.

Other methods known for fabricating microstructures include rapid prototyping technology, such as stereolithography, melt deposition modeling, and LIGA (a German abbreviation for lithography, electroplating, and molding). One particular rapid prototype development technology for making microstructures is known as an electrochemical manufacturing process, such as EFAB ^™ , developed by Microfabrica Inc., which is located in Van Nuys, California. The electrochemical manufacturing process typically begins by depositing a sacrificial material on a bare substrate in a desired pattern. The sacrificial material carries the microstructure like a scaffold during the manufacturing process. Then a structural material is deposited on the sacrificial material. The sacrificial material and structural materials are then precisely planarized and the process is repeated until the microstructure is fully assembled. The sacrificial material is eventually removed, for example by a highly selective etching process, to leave the completed microstructure formed from the structural material. The use of electrochemical fabrication facilitates the fabrication of microstructures having an extraordinary degree of geometric complexity, including the ability to create assemblies of separate, independently formed components. However, electrochemical manufacturing and other conventional rapid prototype development processes are undesirably expensive and time-consuming, especially for applications such as automotive fuel cells.

There is a continuing need for a method of producing radiation cured structures that is less expensive and less time consuming compared to the rapid prototyping methods. Desirably, the method facilitates the low cost training of radiation cured components for fuel cells and other applications.

SUMMARY OF THE INVENTION

In accordance with the present disclosure, surprisingly, a method of making radiation cured structures has been discovered which is less expensive and less time consuming than conventional rapid prototyping methods and which facilitates the low cost formation of radiation cured fuel cell components for fuel cells and other applications.

In a first embodiment, a method of fabricating a radiation cured structure includes the steps of providing a first radiation sensitive material and a second radiation sensitive material adjacent to the first radiation sensitive material. The first radiation-sensitive material has a first sensitivity. The second radiation-sensitive material has the first sensitivity and a second sensitivity, which is different from the first sensitivity. At least one mask is placed between at least one radiation source and the radiation-sensitive materials. The mask has a plurality of substantially radiation-transmissive openings formed therein. The first and second radiation-sensitive materials are then irradiated by the radiation-transparent openings in the at least one mask with a plurality of radiation beams to form a first construct in the first radiation-sensitive material and a second construct in the second radiation-sensitive material. The first construct and the second construct work together to form the radiation-cured structure.

In another embodiment, a method of making a radiation cured structure comprises the steps of providing a first radiation curable material, wherein the first radiation curable material has a first sensitivity including at least one of a first cure rate, a first initiation rate, a sensitivity to a first radiation frequency, and a sensitivity a first radiation amplitude and a sensitivity to a first radiation type comprises; Providing a second radiation-curable material adjacent to the first radiation-curable material, the second radiation-curable material having the first sensitivity and a second sensitivity having at least one of a second cure rate, a second initiation rate, a sensitivity to a second radiation frequency, and a sensitivity to one second radiation amplitude and sensitivity to a second type of radiation, wherein the second sensitivity is different from the first sensitivity; placing at least one mask between at least one radiation source and the first and second radiation-curable materials, the mask having a plurality of substantially radiation-transparent openings formed therein; and exposing the first and second radiation-curable materials having a plurality of radiation beams through the radiation-transparent openings in the mask to form a first construct in the first radiation-curable material and a second construct in the second radiation-curable material. The first construct and the second construct work together to form a radiation-cured structure.

In a further embodiment, a method of making a radiation-cured structure comprises the steps of: providing a first radiation-dissociable material, the first radiation-dissociable material having a first sensitivity including at least one of a first dissociation rate, a sensitivity to a first radiation frequency, a sensitivity to a first radiation amplitude; has a sensitivity to a first type of radiation; Providing a second radiation-dissociable material adjacent to the first radiation-dissociable material, the second radiation-dissociable material having the first sensitivity and a second sensitivity having at least one of a second dissociation rate, a sensitivity to a second radiation frequency, a sensitivity to a second radiation amplitude, and a sensitivity to a second type of radiation, wherein the second sensitivity is different from the first sensitivity; placing a mask between at least one radiation source on the first and second radiation-dissociable materials, the mask having a plurality of substantially radiation-transparent openings formed therein; and exposing the first and second radiation-dissociable materials having a plurality of radiation beams through the radiation-transparent openings in the mask to form a first construct in the first radiation-dissociable material and form a second construct in the second radiation-dissociable material. The first construct and the second construct work together to form the radiation-cured structure.

DRAWINGS

The foregoing and other advantages of the present disclosure will become apparent to those skilled in the art from the art The following detailed description, in particular, when considered in light of the drawings described herein, will be readily understood.

The 1 FIG. 10 is a schematic flow diagram of a method of manufacturing a radiation-cured microstructure according to an embodiment of the present disclosure, showing the formation of the radiation-cured microstructure from the radiation-sensitive materials having different sensitivities. FIG.

the 2 FIG. 10 is a schematic flow diagram of a method of making a radiation-cured microstructure according to another embodiment of the present disclosure, showing the formation of the radiation-cured microstructure from the radiation-curable materials having different sensitivities. FIG.

the 3 FIG. 10 is a schematic flow diagram of a method of making a radiation-cured microstructure according to another embodiment of the present disclosure, showing the formation of the radiation-cured microstructure from the radiation-dissociable materials having different sensitivities. FIG.

the 4A - 4C 10 are schematic cross-sectional side views illustrating a method of manufacturing a radiation-cured microstructure according to an embodiment of the present disclosure; and

the 5A - 5C 10 are schematic cross-sectional side views illustrating a method of manufacturing a radiation-cured microstructure according to another embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

The following detailed description and the accompanying drawings describe and illustrate various embodiments of the present invention. The description and drawings serve to enable one skilled in the art to make and use the present application and are not intended to limit the scope of the present invention in any way. In view of the methods disclosed herein, the steps shown are exemplary in nature and, thus, are not necessary or critical.

Like in the 1 As shown, the present disclosure includes a method 100 for producing a radiation-cured structure from at least one first radiation-sensitive material and a second radiation-sensitive material. The radiation-cured structure is formed from a variety of radiation-cured constructs formed individually in each of the first and second radiation-sensitive materials from a plurality of radiation-cured elements or construct features. The radiation-cured constructs formed in each of the first and second radiation-cured materials cooperate with each other to form the radiation-cured structure.

The procedure 100 First, the step of providing 102 of a substrate. The substrate may be formed of any material that allows the formation of polymer structures thereon.

In certain embodiments, the substrate is a substantially planar foil. One skilled in the art should recognize, however, that the substrate may be shaped to provide the radiation cured structure having the desired shape. The substrate may be electrically non-conductive, such as plastic, or may be electrically conductive, such as stainless steel. The substrate may have holes formed therein which facilitate removal of excess uncured radiation-sensitive material after fabrication of the radiation-cured structure.

The substrate may further be provided with a coating or surface treatment for bonding and removal from the radiation-cured structure. As a non-limiting example, the substrate may include a coating adapted to adhere to the uncured radiation-sensitive material. The surface treatment may further comprise removing a cured polymer from the substrate. In particular, during manufacture of the radiation cured structure, a back side of the substrate is placed on a flat surface or on a stationary base plate and has a coating to prevent, for example, unwanted contamination or plating of the substrate through repeated use. The stationary base plate may be, for example, a porous vacuum chuck with pressure assisted release to selectively hold the substrate in place during the manufacturing process. One skilled in the art can select suitable surface treatments, including coatings, as desired.

The procedure 100 further comprises the step of applying 104 of the first radiation-sensitive material on the substrate and the step of applying 106 of the second radiation-sensitive material on the first radiation-sensitive material. It It should be noted that, for example, without providing the substrate as a free-standing film, the first radiation-sensitive material may be provided instead of the providing step 102 of the previously described substrate. The step of applying 104 . 106 The first and second radiation-sensitive material may alternatively comprise prelaminating the first and second radiation-sensitive materials and applying the prelaminated first and second radiation-sensitive materials to the substrate.

The radiation-sensitive materials according to the present disclosure include radiation-curable materials and radiation-dissociable materials. The term "radiation-curable material" is defined herein as any material which is at least one of radiation-initiated, polymerized or crosslinked. It should be noted that an increase in temperature may also be employed to at least partially complete the polymerization or crosslinking of the radiation-curable materials after initiation by exposure to radiation. The term "radiation-dissociable material" is defined herein as any material that exhibits at least one of a cleavage of the polymer backbone and a removal of the crosslinking by exposure to radiation. As a non-limiting example, the radiation-dissociable material can be solubilized by sufficiently breaking the crosslinks and / or cutting the polymer backbone of the radiation-dissociable material in a solvent.

As non-limiting examples, the radiation-curable materials can include one of a liquid photomonomer and a substantially solid radiation-curable polymer. The liquid photomonomer can be one from Jacobsen in the U.S. Patent No. 7,382,959 and U.S. Patent Application Serial No. 11 / 801,908. Other nonlimiting examples of suitable photomonomers include monomers which polymerize via free radical polymerization when exposed to UV radiation (wavelength between about 250 mm and about 400 mm). The photomonomer may comprise any suitable free radical photopolymer material, such as urethanes (polyurethanes), acrylates, methacrylates, and cationic polymers, such as photohardened epoxies. For example, suitable liquid photomonomers may have a shift in the refractive index during photopolymerization to provide self-propagating waveguides. If desired, other photomonomers may also be used.

Suitable substantially solid radiation-curable polymers can include negative photoresist polymers. Negative photoresist polymers undergo a photoinitiation process which, for example, results in curing of the negative photoresist polymer by polymerization or polycondensation. When the polymerization or polycondensation reaction takes place substantially simultaneously, the process is referred to as "photohardened". When only the reaction species are generated by the photoinitiation process and a subsequent step, such as heating, is required to produce the polymerization or polycondensation, the process is referred to as "photoinitiated." It should be noted that even though a post cure heat treatment may be necessary to complete the polymerization step, substantially stable engineering features can also be produced in the negative photoresist polymer during the initial exposure to radiation. The substantially solid radiation-curable polymers can only go through the initiation process and the curing process can also be done much later, due to the inherent stability and limited diffusion rate of the chemical species in the solid radiation-curable polymers, without significant feature degradation. It should be noted that most photoinitiated polymers begin the curing process at the start of the initiation process, but the kinetics of the reaction at the irradiation temperature are so slow that little, if any, polymerization or polycondensation occurs before heating the negative photoresist polymer to a desired cure temperature can.

A particular negative photoresist polymer is that available from Microchem Corporation of Newton, Massachusetts, commercially available epoxy-based SU-8 2000 ^™ . The negative photoresist polymer SU-8 2000 ^™ is curable by UV radiation. It should be noted that other substantially solid radiation-curable polymers can also be used.

As a non-limiting example, the radiation-dissociable materials may include positive photoresist polymers. Positive photoresist polymers begin as crosslinked polymers, but may contain photoinitiators which, when irradiated with a particular radiation, produce chemical species that dissociate the polymer by at least one of breaking the crosslinks or cutting the polymer backbone. The dissociation renders the positive photoresist polymer soluble in the areas which have been exposed to the radiation. Areas where the positive photoresist polymer remains are masked instead of being irradiated, as shown in FIG Case of the negative photoresist polymers described above is the case. In certain embodiments, the positive photoresist polymers are sensitive to radiation, for example, ultraviolet radiation or electron beam radiation, without the need for photoinitiators. For example, the positive photoresist polymer itself may be damaged by the radiation and the remaining cut chains become soluble in a solvent. If desired, other types of positive photoresist polymers can be used.

The first radiation-sensitive material has a first sensitivity. The second radiation-sensitive material has a second sensitivity, which is different from the first sensitivity. Embodiments in which the first radiation-sensitive material and the second radiation-sensitive material each share the first sensitivity or the second sensitivity are also within the scope of the present disclosure. As disclosed herein, the sensitivity with respect to the radiation-curable materials is at least one of a cure rate, an initiation rate, a sensitivity to radiation frequency, a sensitivity to radiation amplitude, and a radiation-type sensitivity. The sensitivity to radiation-dissociable materials is at least one of a dissociation rate, a sensitivity to radiation frequency, a sensitivity to radiation amplitude and a sensitivity to radiation type. It should be noted that when applying 104 . 106 the first and second radiation-sensitive materials on the substrate in the first and second radiation-sensitive materials by the irradiation 110 the first and second radiation-sensitive materials with radiation selected for the respective first and second sensitivities, different radiation-cured constructs can be formed. As a result, radiation-hardened structures with a high degree of geometric complexity can be produced.

It should further be noted that the use of a first radiation-sensitive material having the first sensitivity and a second radiation-sensitive material sharing the first sensitivity; but also a second sensitivity different from the first sensitivity, also falls within the scope of the present disclosure. It should also be noted that for purposes of large scale production and related motives for recovery, the dual or overlapping sensitivities of the first radiation-sensitive material and the second radiation-sensitive material may be particularly preferred.

In a further embodiment, the method 100 the step of applying a third radiation-sensitive material to the second radiation-sensitive material. The third radiation-sensitive material has a third sensitivity. The third sensitivity may be the same as or, if desired, different from the first and second sensitivities. In one example, the third sensitivity is substantially the same as the first sensitivity. In a particular example, the third sensitivity is different from the first and second sensitivities. One skilled in the art should appreciate that this could form a resulting radiation-cured structure having layers of substantially the same construct with a layer of a different construct interposed therebetween. It should also be noted that any desired number of radiation-sensitive materials may be employed in any desired arrangement, such as laminated or otherwise, within the scope of the present disclosure.

After the steps of applying 104 . 106 the first and second radiation-sensitive materials on the substrate include the method 100 the step of placing 108 at least one mask between at least one radiation source and the first and second radiation-sensitive materials. In certain embodiments, the mask is provided as an integral part of the radiation source. It can be used a variety of masks and a variety of radiation sources. The mask has a plurality of substantially radiation-transparent openings. For example, in the embodiment where the third radiation-sensitive material is also employed, the mask is placed between the at least one radiation source and the first, second and third radiation-sensitive materials. It should be noted that, if desired, a first mask and a first radiation source may be disposed on a first side of the first and second radiation-sensitive materials and a second mask and a second radiation source disposed on a second side of the first and second radiation-sensitive materials can.

For example, the material forming the mask may be a substantially radiation-transparent material with respect to ultraviolet (UV) radiation, such as quartz glass. The openings may be holes or in the opaque, radiation blocking coating disposed on the substantially radiation transparent mask material. In an illustrative embodiment, the mask has a plurality of apertures approximately 10 microns in diameter. As another non-limiting examples may include the mask material of one of crown glass, Pyrex glass and a polyethylene terephthalate such as a ^Mylar® film. The mask can be removed for reuse after irradiation and cleaning. Also, multiple masks having different patterns and types of the plurality of openings may be used. The openings may have shapes that provide the radiation cured elements with desired cross-sectional shapes. For example, the openings may be substantially circular to form radiation cured elements having elliptical cross-sectional shapes. One skilled in the art may, as desired, select suitable mask materials, aperture sizes and shapes, and resulting construct arrangements.

The procedure 100 includes the step of irradiating 110 the first and second radiation-sensitive materials having a plurality of radiation beams. The beams are projected through the radiation-transparent openings in the at least one mask and contact the first and second radiation-sensitive materials. One skilled in the art can select the radiation source to produce electromagnetic radiation or particle radiation, as desired. For example, the beams used to irradiate the radiation-sensitive material may be generated by a mercury arc lamp which provides UV radiation beams. One skilled in the art will understand that beams of other wavelengths, such as infrared, visible light and x-rays, and beams from other sources, such as incandescent and lasers, may be used. Particle radiation, such as an electron beam from a cathode radiation source, may also be used. It should also be noted that the beams may be collimated, partially collimated, or uncollimated, as desired.

For example, the plurality of beams may include a plurality of first beams and a plurality of second beams. In certain embodiments, the first beams may be different from the second beams in at least one of the frequency, the amplitude, and the type. The first and second radiation-sensitive materials may, if desired, be exposed simultaneously or sequentially to a plurality of radiation beams. The first beams may be different from the second beams in at least one of the cross-sectional shape and the angle of incidence relative to the surface of one of the first, second and optionally third radiation-sensitive materials. As another non-limiting example, the plurality of first beams are provided by a first radiation source having a first mask, and the plurality of second beams are provided by a second radiation source having a second mask. Any desired variation in radiation frequencies, radiation amplitudes, types of radiation, cross-sectional shapes, angles, masks, and radiation sources may be employed within the scope of the present disclosure.

The steps of applying 104 . 106 the first and second radiation-sensitive materials and the irradiation 110 The first and second radiation-sensitive materials have been described above with respect to the simultaneous exposure of the first and second radiation-sensitive materials. It should be noted that the first and second radiation-sensitive materials may also be exposed in a non-simultaneous manner. For example, each of the first and second radiation-sensitive materials may be applied independently and then exposed to the radiation beams. As another example, the first radiation-sensitive material may be applied first and then exposed to the first beams. The second radiation-sensitive material may then be applied to the first radiation-sensitive material. The second radiation-sensitive materials may have increased sensitivity and may be irradiated with the second beams for a duration that would not significantly affect the first radiation-sensitive material. In this way, construct features in the less sensitive first radiation-sensitive material would not be carried by the more sensitive second radiation-sensitive material.

With at least one liquid radiation-sensitive material, it is likewise possible to use a substantially solid radiation-sensitive material. If simultaneous exposure is desired, for example, the substantially solid first radiation-sensitive material can be applied to the substrate. The liquid second radiation-sensitive material is then applied to the substantially solid first radiation-sensitive material. Each of the first and second radiation-sensitive materials may be selected to have a different sensitivity. If the variation in sensitivity between the first and second radiation-sensitive materials is one of the speed, the construct features in the less sensitive radiation-sensitive material would be carried by the more sensitive radiation-sensitive material. The construct features in the more sensitive radiation-sensitive material would not be carried by the less sensitive radiation-sensitive material. If the variation in sensitivity to the Frequency or the type of radiation is due, the construct features unique to the first and second radiation-sensitive materials can be generated separately. The construct features crossing the interface between the first and second radiation-sensitive materials may be formed by simultaneously exposing the first and second radiation-sensitive materials to both frequencies and / or types of radiation. For example, the first and second radiation-sensitive materials may be exposed to provide less than complete cure, after which the remaining uncured material is then removed and the first and second radiation-sensitive materials cured simultaneously for co-cure at the interface.

If non-simultaneous exposure is desired, the substantially solid first radiation-sensitive material may be applied and then irradiated with the radiation beams. The liquid second radiation-sensitive material is then applied to the substantially solid first radiation-sensitive material. Typically, the liquid second radiation-sensitive material may be selected to have greater sensitivity than the sensitivity of the substantially solid first radiation-sensitive material. Construct features formed in the liquid second radiation-sensitive material are thereby not supported by the substantially solid first radiation-sensitive material.

One skilled in the art should understand that the first and second radiation-sensitive materials may include, for example, liquid layers having different depths. As a non-limiting example, the liquid radiation-sensitive material may be applied to the substrate and then irradiated to form desired constructive features. Additional liquid radiation-sensitive material may then be added to increase the height of the initially liquid radiation-sensitive material. The additional liquid radiation-sensitive material is irradiated and the intensity of the radiation beams and the irradiation time are controlled so that the new construct features extend only through the new layer of the liquid radiation-curable material. Alternatively, the intensity of the beams and the exposure time may be controlled so that the new construct features extend into construct features formed in the originally liquid radiation-sensitive material.

After the step of irradiation 110 The first and second materials with the plurality of beams comprise the method 100 the step of training 112 the first and second constructs of the first radiation-sensitive material or the second radiation-sensitive material. It should be noted that the step of training 112 the first and second radiation-sensitive materials directly from the step of irradiation 110 the first and second radiation-sensitive materials may result with the plurality of radiation beams. Alternatively, the step of forming 112 further reworking the first radiation-sensitive material and the second radiation-sensitive material after the step of irradiating 110 the first and second radiation-sensitive materials having the plurality of radiation beams. For example, the post-processing may include heating the first and second radiation-curable materials. The heating may facilitate at least one of the polymerization and crosslinking of at least one of the first radiation-sensitive material and the second radiation-sensitive material when at least one of the first radiation-sensitive material and the second radiation-sensitive material is a radiation-curable material having a degree of initiation by irradiation with the radiation Has undermined bundles of rays. In an alternative embodiment, the heating may facilitate dissociation of one of the first radiation-sensitive material and the second radiation-sensitive material when at least one of the first radiation-sensitive material and the second radiation-sensitive material is a radiation-dissociable material that has undergone a degree of dissociation by exposure to radiation beams , As desired, suitable temperatures and heating times may be selected.

The first radiation-sensitive material is irradiated and forms a first construct in the first radiation-sensitive material. The second radiation-sensitive material is irradiated and forms a second construct in the second radiation-sensitive material. The third radiation-sensitive material forms a third construct, where the third radiation-sensitive material is irradiated with the radiation beams. The first construct, the second construct, and optionally the third construct are formed from a plurality of radiation cured elements and cooperate to form the radiation cured structure. It should be understood that according to the present method, a plurality of the radiation cured elements may be formed, including, for example, support members, radiation cured films, and solid radiation cured polymer structures.

In a particular embodiment, the radiation-cured structure comprises a microstructure. The microstructure can be a variety of first support members extending along a first direction, having a plurality of second support members extending along a second direction, having a plurality of third support members extending along a third direction, and a plurality of fourth support members extend along a fourth direction. The first, second, third and fourth support members may penetrate each other at a plurality of nodes. It should be noted that the first, second, third and fourth support members, if desired, can not penetrate one another or penetrate each other on the plurality of nodes on an intermittent base. The first, second, third and fourth support elements form a continuous, three-dimensional, self-supporting, cellular structure.

Although the microstructure having the plurality of first, second, third and fourth support members as described above may have a quadruple architectural symmetry, one of ordinary skill in the art should note that other architectures for microstructure such as 3-fold symmetry and 6-axis symmetry symmetry can be used within the scope of the present disclosure. For example, the particular architecture may be selected to increase the connectivity of the micro-support structure and to reduce the susceptibility to bending and buckling of the micro-support structure under a force. The selected architecture may be symmetric or asymmetric as desired. The architecture can also be selected to optimize the strength and rigidity of the microstructure. One skilled in the art should further understand that, if desired, other architectures may be used for the microstructure.

Exemplary architectures of the microstructure structure are described by Jacobsen in US Pat U.S. Patent No. 7,382,959 and US Patent Application Serial No. 11 / 801,908. For example, the plurality of first support members may be defined by a plurality of the first self-propagating polymer support waveguides. The plurality of second support members may be defined by a plurality of second self-propagating polymeric carrier waveguides. The plurality of third support members may be formed by a plurality of third self-propagating polymeric carrier waveguides. The plurality of fourth support members may be formed by a plurality of fourth self-propagating polymeric carrier waveguides. If desired, other suitable means for forming the microstructure may be employed.

One of ordinary skill in the art should note that the particular microstrat structure may be formed, if desired, by at least one of: 1) selecting the angles and patterns of the support members with respect to each other; 2) adjusting the packing or relative density of the resulting cellular structure; and 3) selecting the cross-sectional shapes and the dimensions of the supporting elements. In particular, support members having an elliptical support cross-sectional shape can protect against decomposition with differences in the thermal expansion coefficient. If desired, other cross-sectional shapes may be used.

It should be noted that the radiation-cured structure according to the present disclosure can be made by the combined use of radiation-curable materials and radiation-dissociable materials. For example, the radiation-cured structure may be formed from both a negative photoresist and a positive photoresist, as described above. All of the negative and positive photoresists can be applied side by side in an uncured state. The negative and positive photoresists can be selected to have different radiation sensitivities. The negative photoresist may be photoinitiated or at least partially during the exposure step 110 of the negative resist to radiation beams to be cured. After exposure of the negative photoresist to form the construct features and removal of residual uncured material, the uncured positive photoresist and the negative photoresist may be co-cured. This allows the negative photoresist construction features to crosslink with the positive photoresist at the interface boundary. The positive photoresist is then exposed to radiation beams to dissociate the positive photoresist material in desired areas without adversely affecting the construct formed in the negative photoresist. The radiation-cured structure can thereby be formed both from the first radiation-curable material and from the second radiation-dissociable material.

The procedure 100 The present disclosure may further include the step of removing an uncured portion of the first and second radiation-sensitive materials. It should be understood that the term "uncured radiation-sensitive material" within the scope of the present disclosure may also include dissociated radiation-sensitive material. The uncured part may be a residual part of the first and second radiation-curable materials which after irradiation with the Cells were uncured, or a portion of the first and second radiation-dissociable materials, which were cut or otherwise solubilized by the irradiation of the bundles in solvent. The step of removing the uncured part typically occurs after at least one of the step of irradiating 110 the first and second radiation-sensitive materials having the plurality of radiation beams to cure the first and second radiation-sensitive materials. As a non-limiting example, the step of removing the uncured portion of the first and second radiation-sensitive materials may include rinsing the radiation-cured structure with the solvent. One skilled in the art should note that suitable solvents do not substantially degrade the irradiated radiation cured structure during the step of removing the uncured portion of the first and second radiation-sensitive materials.

It should be noted that after the radiation cured structure is fabricated, the radiation cured structure may be further processed to enhance at least one of the strength, electrical conductivity, and environmental resistance thereof. As non-limiting examples, the method according to the present disclosure may further comprise at least one of the steps of metallizing, carbonizing, and ceramifying the radiation-cured structure. Composites containing the radiation-cured structure may also be formed, as described, for example, in US Patent Application Serial No. 12 / 008,479 to Jacobsen et al., Which is hereby incorporated by reference in its entirety.

In one embodiment, the radiation cured structure can be metallized by plating the radiation cured elements with a metal coating. For example, the metal coating may be substantially oxidation resistant, reduction resistant, and acid resistant. The metal coating may include a noble metal selected, for example, from the group consisting of ruthenium (Ru), rhodium (Rh), palladium (Pd), silver (Ag), iridium (Ir), platinum (Pt), and osmium (Os) and alloys thereof. In a particular embodiment, the metal coating is gold (Au). In another particular embodiment, the metal coating is tantalum (Ta). Another suitable metal coating may include nickel (Ni) alloys, such as alloys of nickel (Ni) and chromium (Cr) or of nickel (Ni) and cobalt (Co). It should be recognized by those skilled in the art that the metal coating may include mixtures or alloys of the previously identified metals. Other electrically conductive metals and materials may also be used if desired.

The metal coating may be deposited on the radiation cured structure by at least one of electron beam evaporation, magnetron sputtering, physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrodeposition, electroless deposition, flame spray deposition, brush plating, and the like. Solution-based electroplating techniques that involve immersing the radiation-cured structure in a plating bath can also be used. The application of metal in the form of a slurry powder and the subsequent heating of the slurry powder to form the metal coating may also be employed. One skilled in the art may select more than one deposition technique to account for differences between the zero and zero direction characteristics of the selected deposition techniques. In certain embodiments, the metal coating may be deposited substantially uniformly on both the inner and outer surfaces of the radiation cured structure. Suitable means for metallizing the radiation-cured structure may be selected as desired.

One skilled in the art should understand that the radiation cured structure can be carbonized. The carbonation of the radiation-cured structure may cause the radiation-cured structure to become electrically conductive. Jacobsen discloses open cell carbon structures and a method for making the same from a polymeric matrix material in US Patent Application Serial No. 11 / 870,379, the disclosure of which is hereby incorporated by reference in its entirety. Other suitable methods for carbonizing the radiation-cured structure can also be used.

It should be noted that the radiation-cured structure may be ceramified by coating the radiation-cured structure with a suitable metal oxide or ceramic. In certain illustrative embodiments, at least a portion of the radiation cured structure may be coated with the metal oxide or ceramic to provide the appropriate level of flexural strength or electrical conductivity. Suitable ceramic structures and methods for ceramifying radiation cured structures are described by Gross et al. in US Patent Application Serial No. 12/074, 727, the entire disclosure of which is hereby incorporated by reference. Other suitable methods of ceramifying the radiation cured structure may also be used.

The procedure 100 The present disclosure includes the step of applying a filter layer between the first radiation-sensitive material and the second radiation-sensitive material. The filter layer may be a layer of another radiation-sensitive material that is substantially opaque to radiation to which the first and second radiation-sensitive materials are sensitive. In an illustrative embodiment, prior to irradiating the second radiation-sensitive material, the filter layer protects with at least a portion of the plurality of radiation beams when the first radiation-sensitive material is irradiated. In certain cases, the filter layer is an optical filter layer. For example, the filter layer can be arranged between the first radiation-sensitive material and the second radiation-sensitive material. The filter layer may thereby prevent radiation beams of selected frequency, amplitude, or type from causing the formation of the first construct in the first radiation-sensitive material when the second radiation-sensitive material is irradiated with the radiation beams of the radiation source. The filter layer may also have a radiation sensitivity which is different from the sensitivity of the first and second radiation-sensitive materials. Therefore, if desired, another construct of the radiation-cured structure may also be formed in the filter layer.

The embodiments of the present invention which are incorporated in the 2 and 3 are similar to the embodiment shown in FIG 1 is shown, except for the points described below. For the sake of clarity, similar, in the 1 shown steps in the 2 and 3 with the same reference numerals in the 200's and 300's instead of the 100's.

Like in the 2 As shown, the first radiation-curable material has the first sensitivity, and the second radiation-curable material has the second sensitivity, which is different from the first sensitivity. The procedure 200 includes the steps of providing 202 of the substrate, applying 204 of the first radiation-curable material on the substrate, the application 206 of the second radiation-curable material on the first radiation-curable material, placing 208 at least one mask between the at least one radiation source and the first and second radiation-curable materials and the irradiation 210 the first and second radiation-curable materials having a plurality of radiation beams through the radiation-transparent openings in the at least one mask. The procedure 200 includes the step of curing 212 the first and second radiation-curable materials having the different first and second sensitivities. The first construct in the first radiation-curable material and the second construct in the second radiation-curable material are thereby fabricated and cooperate to form the radiation-cured structure. It should also be noted that the first radiation-curable material at the interface with the second radiation-curable material before curing 212 of the second radiation-curable material may be substantially uncured. After removing the uncured radiation-curable material, the first and second radiation-curable materials can be cured simultaneously to form bonds at the interface. The at least partial undercuring of the first radiation-curable material prior to curing 212 The second radiation-curable material may improve the adhesion of the first construct to the second construct. It should further be noted that the difference in sensitivities between the first radiation-curable material and the second radiation-curable material allows the first construct in the first radiation-sensitive material to be formed in front of the second construct in the second radiation-sensitive material or vice versa if desired becomes.

In an illustrative example, the first and second radiation-curable materials are selected to have different sensitivities to radiation frequency. In a particular embodiment, the first and second radiation-curable materials are photoinitiated polymers. The first and second radiation-curable materials may be applied together and each has, for example, a sensitivity to a different radiation frequency. The first and second radiation-curable materials may be irradiated simultaneously or sequentially at different radiation frequencies. For example, after the features of the first and second constructs in the first and second radiation-curable materials have been initiated, each of the first and second radiation-curable materials can be simultaneously heated to a desired curing temperature. The heating may cause at least one of polymerization and crosslinking of the first and second constructs to proceed. Because each of the first and second constructs are cured at the same time, the construct features crossing the interface between the first and second radiation-curable materials may carry polymerization or crosslinking across the interface. This can be a desirable level of adhesion between the first and second constructs.

In another embodiment, the first and second radiation-curable materials are photohardened polymers. When all of the construct features for each of the first and second radiation-curable materials are irradiated at substantially the same time, the reactions in each of the first and second radiation-curable materials occur substantially simultaneously and the polymerization reaction is carried across the interfaces between the first and second radiation-curable materials , For example, where the construct features can not all be irradiated at the same time because of the limitations of the masking or the radiation sources, the construct features in each of the first and second radiation-curable materials that do not open into the other of the first and second radiation-curable materials can be irradiated separately, for example become. The construct features that do not cross the boundary may be formed simultaneously in the first and second radiation-curable materials on either side of the boundary. It should be noted that these restrictions may not be so stringent if, for example, as previously described, one of the first and second radiation-curable materials does not fully cure during the irradiation process.

In another illustrative example, the first and second radiation-curable materials are selected to have different rates of initiation. It should be noted that the photoinitiation process according to the present process 200 may be a function of at least one of the radiation intensity and the irradiation time. Each can be varied so that the irradiation changes. For example, the features of the construct formed in one of the first and second radiation-curable materials having the slower rate of initiation are desirably carried into the adjacent one of the first and second radiation-curable materials at the faster rate of initiation. For example, additional construct features may be added to the one of the first and second radiation-curable materials having the faster initiation rate. After the initiation process, the first and second constructs may be cured by raising the temperature of the first and second radiation-curable materials. It should be noted that all features must be initiated prior to the onset of the curing process to allow the construct features to cross the interfaces.

In another illustrative example, the first and second radiation-curable materials are selected to have a different cure rate from each other. The processing of the first and second radiation-curable materials at the different cure rate may be very similar to the processing of the first and second radiation-curable materials at the different initiation rate. It should be noted that the curing of the first and second constructs occurs during irradiation. However, equal effects with respect to the speed of irradiation are applicable. For example, the construct features formed in one of the first and second lower durometer radiation-curable materials are preferably carried by the one of the first and second radiation-curable materials having the faster cure rate. The one of the first and second radiation-curable materials having the faster cure rate may contain additional features if desired.

In another illustrative example, the first and second radiation-curable materials are selected to have a different sensitivity from the type of radiation. As described above, a plurality of types of radiation can be used to initiate the curing reaction. Typically, curing (eg, at least one of initiation, polymerization and crosslinking) will be initiated by some form of electromagnetic radiation. Furthermore, however, other types of radiation, such as particulate beam radiation, may also be used to initiate curing.

For a photoinitiated polymer system in which the first and second radiation-curable materials also have different sensitivities to the radiation type, the method is similar to the method of varying the frequency of the radiation. The first and second radiation-curable materials are each applied and have a sensitivity to different types of radiation. The first and second radiation-curable materials may then be irradiated with different types of radiation, either simultaneously or sequentially. After initiating the construct features in the first and second radiation-curable materials, each of the first and second radiation-curable materials is heated simultaneously to the curing temperature at which polymerization and / or crosslinking of all construct features occurs. Because the construct features are formed at substantially the same time, the construct features, which cross the interface between the first and second radiation-curable material, preferably the polymerization and / or crosslinking across the interface.

For a photo-cured polymer system in which each of the constructive features for the first and second radiation-curable materials can be irradiated at substantially the same time, the curing in the first and second radiation-curable materials can occur simultaneously. The resulting polymerization reactions can thereby be carried over the interface between the first and second radiation-curable materials. For example, if the construct features can not all be irradiated at substantially the same time because of the limitations of the mask or the radiation sources, the construct features in the first radiation-curable material that does not set in the second radiation-curable material can be formed separately. The construct features that cross the interfaces may be formed in the first and second radiation-curable materials on both sides of the interface simultaneously.

Like in the 3 As shown, the first radiation-dissociable material has a first sensitivity and the second radiation-dissociable material has a second sensitivity that is different from the first sensitivity. The procedure 300 includes the steps of providing 302 a substrate, the application 304 of the first radiation-dissociable material on the substrate, the application 306 of the second radiation-dissociable material on the first radiation-dissociable material, placing 308 at least one mask between the at least one radiation source and the first and second radiation-dissociable materials and the irradiation 310 the first and second radiation-dissociable materials having the plurality of radiation beams through the radiation-transparent openings in the at least one mask. The procedure 300 further comprises the step of dissociating 312 the first and second radiation-dissociable materials having the different first and second sensitivities. Thereby, the first construct becomes in the first radiation-dissociable material and the second construct is formed in the second radiation-dissociable material and these cooperate with each other to form the radiation-cured structure. It should be noted that the difference in sensitivities between the first radiation-dissociable material and the second radiation-dissociable material allows the first construct in the first radiation-sensitive material to be formed in front of the second construct in the second radiation-sensitive material or, if desired, vice versa ,

In an illustrative example, the first and second radiation-dissociable materials are selected to have a different sensitivity to radiation frequency. For example, if the first and second radiation-dissociable materials are positive photoresists, the first and second radiation-dissociable materials become prior to the irradiation step 310 the first and second radiation-dissociable materials with radiation beams preferably fully cured and crosslinked with each other. The desired construct features may thereby be carried over the interface between the first and second radiation-dissociable materials. It should be understood that the first and second radiation-dissociable materials may be irradiated with the beams at the various frequencies in any order and then the irradiated areas may be dissolved by the solvent to leave the desired first and second constructs.

In another illustrative example, the first and second radiation-dissociable materials are selected to have different dissociation rates. It should be noted that as dissociation rates of the first and second radiation-dissociable materials are different from each other, complex constructs can be generated. One skilled in the art will understand that by the step of irradiating 310 one of the first and second radiation-dissociable materials having the slowest dissociation rate are carried through the entire resulting radiation-cured structure. Additional material can be removed from one of the first and second radiation-dissociable materials at the faster rate of dissociation without significantly affecting the other of the first and second radiation-dissociable materials at the slower dissociation rate. However, in general, a considerable difference in the corresponding dissociation rates is desirable. As non-limiting examples, a difference in dissociation rates of about 10: 1 may be sufficient if there are only two radiation-dissociable materials; if there are three radiation-dissociable materials, a difference in dissociation rates of about 100: 1 may be sufficient; and if there are more than three radiation-dissociable materials, a difference in dissociation rates of about 10,000: 1 may be sufficient. The corresponding Dissociation rates of the radiation-dissociable materials can be selected as desired.

In another illustrative example, the first and second radiation-dissociable materials may be selected to have different sensitivities to the type of radiation. The formation of the radiation-cured structure from the first and second radiation-dissociable materials having sensitivities to different types of radiation may be similar to the process for different sensitivity to frequency previously described. As a non-limiting example, the first radiation-dissociable material may be sensitive to electromagnetic radiation and the second radiation-dissociable material may be sensitive to particle beam radiation. It should be noted, however, that the first radiation-dissociable material, which is sensitive to electromagnetic radiation, is desirably selected to have a minimum sensitivity to particle beam radiation, and vice versa.

It has surprisingly been found that the selective irradiation of layered radiation-sensitive materials according to the methods 100 . 200 . 300 of the present disclosure minimize production cost and fabrication time of radiation cured structures. By grouping together all the lamination operations together, the fabrication of complex radiation cured structures can now be performed on a single unit and in the same facility. The irradiation of the various radiation-sensitive materials with the plurality of radiation sources can be performed by adjusting the masked radiation sources without moving the radiation-sensitive materials. The proceedings 100 . 200 . 300 thus guard against misalignment and tolerance concerns, which typically can result from repeated positioning of masks and radiation-sensitive materials. The radiation-cured structure of the present disclosure may also be made without the need for planarization as practiced in electromechanical fabrication. A single cleaning step may also be used to remove uncured radiation-sensitive materials after the preparation of the radiation-cured structure. Similarly, individual metallization, carbonation and ceramization operations may be performed to prepare the radiation cured structure to provide the radiation cured structure with the desired properties.

Referring now to the 4A - 4C For example, the process of the present invention may involve the preparation of a microstructure 400 using an exclusive sensitivity approach. Although the microstructure 400 in the 4A - 4C As a boom is shown, it should be understood that the formation of other shapes for the microstructure 400 is also within the scope of the present disclosure.

The method of making the microstructure 400 first comprises the steps of providing the first radiation-sensitive material and the second radiation-sensitive material, for example, as one on a substrate 406 applied first layer 402 and second layer 404 , The first shift 402 has a first sensitivity, and the second layer 404 has a second sensitivity, which is different from the first sensitivity. Then a first mask 408 between the at least one radiation source (not shown) and the first and second layers 402 . 404 placed. The first mask 408 has at least one first substantially radiation-transparent opening 410 on, which is formed in this. The first shift 402 and the second layer 404 are then with a first variety of bundles of rays 412 against which the first radiation-sensitive material of the first layer 402 is sensitive and the second radiation-sensitive material of the second layer 404 not sensitive, irradiated. The first variety of beams 412 gets through the first radiation-transparent opening 410 in the first mask 408 projected to a first construct of the microstructure 400 in the first shift 402 train. The first mask 408 is then through a second mask 414 which substitutes at least one second substantially radiation-transparent opening 416 , which is formed in this, has. The first shift 402 and the second layer 404 are then using a second variety of beams 418 against which the second radiation-sensitive material of the second layer 404 is sensitive and the first radiation-sensitive material of the first layer 402 not sensitive, irradiated. The second variety of beams 418 is through the second radiation-transparent opening 416 in the second mask 414 projected to a second construct of the microstructure 400 in the second layer 404 train. The second mask 414 is removed, and the remaining first and second radiation-sensitive materials are removed from the substrate 406 away. This will cause the microstructure 400 , which is composed of the first and second constructs provided.

In another embodiment, which in the 5A - 5C can be shown, the method according to the present disclosure, the Production of a microstructure 500 using an overlapping sensitivity approach. Although the microstructure 500 As a girder and grid network is shown, it should be noted that the design of other shapes is also within the scope of the present disclosure.

The method of making the microstructure 500 first comprises the steps of providing the first radiation-sensitive material and the second radiation-sensitive material, for example, as a first layer, respectively 502 and a second layer 504 , The first shift 502 is on a substrate 506 applied and the second layer 504 gets on the first layer 502 applied. The first shift 502 has a first sensitivity and the second layer 504 has a second sensitivity, which is different from the first sensitivity. In this embodiment, the second layer also shares 504 the first sensitivity with the first layer 502 , A first mask 508 is then between the at least one radiation source (not shown) and the first and second layers 502 . 504 placed. The first mask 508 has at least one first substantially radiation-transparent opening 510 on, which is formed in this. The first shift 502 and the second layer 504 are then with a first variety of bundles of rays 512 to which both the first radiation-sensitive material of the first layer 502 as well as the second radiation-sensitive material of the second layer 504 sensitive, irradiated. The first variety of beams 512 gets through the first radiation-transparent opening 510 in the first mask 508 projected to a first construct of the microstructure 500 in the first shift 502 and the second layer 504 train. The first mask 508 is then through a second mask 514 which substitutes at least one second substantially radiation-transparent opening 516 , which is formed in this, has. The first shift 502 and the second layer 504 be with a second variety of bundles of rays 518 against which the second radiation-sensitive material of the second layer 504 is sensitive and the first radiation-sensitive material of the first layer 502 not sensitive, irradiated. The second variety of beams 518 is through the second radiation-transparent opening 516 in the second mask 514 projected to a second construct of the microstructure 500 in the second layer 504 train. The second mask 514 is removed and the remaining first and second radiation-sensitive materials are removed from the substrate 506 away. This will cause the microstructure 500 , which is composed of the first and second constructs provided.

According to an exemplary embodiment, the microstructure is 500 a completely integrated diffusion medium of flow field carrier and diamond-shaped grid, which is formed from two fixed layers of photoresists. As non-limiting examples, the first layer 502 PerMX ^™ photoresist, which is commercially available from EI du Pont de Nemours and Company, and the second layer may comprise SU-8 ^™ photoresist. The first shift 502 from the PerMX ^™ photoresist is a bottom layer which is on the substrate 506 is applied, and the second layer 504 from the SU-8 ^™ photoresist is a topcoat which is on the first layer 502 is applied. The PerMX ^™ and the SU-8 ^™ each share the same first sensitivity with each other, for example, against UV light at a preset wavelength of about 365 nm. The flow field polymer carrier becomes both in the first layer 502 from the PerMX ^™ as well as in the second layer 504 formed from the SU-8 ^™ layers under UV irradiation at the preset wavelength of about 365 nm as described herein. Only the second layer 504 from the SU-8 ^™ photoresist has an additional photoinitiator which allows for the second layer 504 selectively, a grating pattern is formed, for example, after irradiation with visible light at a preset wavelength of about 470 nm. When irradiated with visible light at the preset wavelength of 470 nm, the diamond-shaped grating in the second layer becomes 504 educated. After both exposures, the whole stack is developed around the unirradiated regions of the first layer 502 and the second layer 504 to remove. An individual, composite microstructure 500 comprising the flow field polymer carrier and the diamond-shaped grid is thereby constructed.

Advantageously, lead into the 4A - 4C and 5A - 5C to a higher degree of integration than what has been achieved in prior art fuel cell construction and normal lithographic processes.

It was further surprisingly discovered that the in the 5A - 5C shown embodiment with overlapping sensitivity, in which the first layer 502 having the first sensitivity and the second layer 504 having both the first sensitivity and the second sensitivity is particularly desirable for large scale manufacturing operations, with equipment costs for alignment, mask fabrication tolerances and polymer recovery being of concern. In particular, if the microstructure 500 through both the first layer 502 as well as the second layer 504 for a secure adhesion between them, the overlapping sensitivity minimizes the need for precise alignment of the first and second ones mask 508 . 514 to one another, as would otherwise be necessary, to form a complete cross-sectional profile at the interface between the first layer 502 and the second layer 504 provide. On the scale of a complete fuel cell component, if the overlapping sensitivity approach is not used, even small differences in thermal expansion between the first mask will result 508 and the second mask 514 change the feature spacing and make it difficult to ensure alignment over the entire area. The overlapping sensitivity embodiment further advantageously allows both angular and upright features to be fabricated in the same layer for a continuous structural feature with a minimum number of steps.

If recovery of the unirradiated polymers in a single cleaning operation is desired, it should also be understood that the photoinitiators of the recovered first layer 502 and the second layer 504 typically mixed when the first and second radiation-sensitive materials from the substrate 506 be removed. In an exclusive sensitivity process, the recovered mixture of radiation-sensitive materials is not readily reusable in either the first layer 502 or the second layer 504 suitable. However, in the overlapping sensitivity approach, the addition of recovered radiation-sensitive material having a dual sensitivity to an original radiation-sensitive material having the dual sensitivity, e.g. B., the second radiation-sensitive material for the second layer 504 , as proved acceptable. Thus, the method of the present disclosure is particularly desirable for large scale manufacturing operations.

While certain representative embodiments and details have been shown for purposes of illustration of the present invention, it will become apparent to those skilled in the art that various changes can be made without departing from the scope of the disclosure, which is further described by the appended claims leave.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 7382959 [0003, 0024, 0043]
• US 11/801908 [0003]
• US 6274288 [0003]
• US 4770739 [0004]

Cited non-patent literature

• Jacobsen et al. in Acta Materialia 55, (2007), pp. 6724-6733 [0003] in Acta Materialia 55, (2007), "Compression behavior of micro-scale truss structures formed from self-propagating polymer waveguides."

Claims (10)

A method of making a radiation cured structure, the method comprising the steps of: Providing a first radiation-sensitive material, wherein the first radiation-sensitive material has a first sensitivity, Providing a second radiation-sensitive material adjacent to the first radiation-sensitive material, the second radiation-sensitive material having the first sensitivity and a second sensitivity different from the first sensitivity; Placing at least one mask between at least one radiation source and the first and second radiation-sensitive materials, the mask having a plurality of substantially radiation-transparent openings, Irradiating the first and second radiation-sensitive materials with a plurality of radiation beams through the radiation-transparent openings in the mask and Forming at least one first construct in the first radiation-sensitive material and a second construct in the second radiation-sensitive material, wherein the first construct and the second construct cooperate with each other to form the radiation-cured structure. The method of claim 1, wherein at least one of the first and second sensitivities is at least one of a cure rate, an initiation rate, a dissociation rate, a sensitivity to radiation frequency, a sensitivity to radiation amplitude, and a sensitivity to radiation type. The method of claim 1, further comprising the step of applying a third radiation-sensitive material to the second radiation-sensitive material, wherein the third radiation-sensitive material has a third sensitivity. The method of claim 3, wherein after the step of irradiating the third radiation-sensitive material with the plurality of radiation beams, the third radiation-sensitive material forms a third construct, wherein the third construct cooperates with the first construct and the second construct to form the radiation-cured structure. The method of claim 1, further comprising the steps of providing a substrate and applying the first radiation-sensitive material to the substrate. The method of claim 1, further comprising at least one of metallizing, carbonizing, and ceramifying the radiation cured structure. The method of claim 1, wherein the plurality of beams comprises a plurality of first beams and a plurality of second beams. The method of claim 7, wherein the plurality of first beams are different from the plurality of second beams in at least one of the frequency, amplitude and type. The method of claim 7, wherein the plurality of first beams are different from the plurality of second beams in at least one of the cross-sectional shape and the angle of incidence relative to the surface of one of the first radiation-sensitive material and the second radiation-sensitive material. The method of claim 1, further comprising the step of depositing a filter layer between the first radiation-sensitive material and the second radiation-sensitive material, wherein the filter layer protects against irradiation of one of the first and second radiation-sensitive materials against at least a portion of the plurality of radiation beams.

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