Sketch-a-TUI: low cost prototyping of tangible interactions using cardboard and conductive ink

Graspable tangibles are now being explored on the current generation of capacitive touch surfaces, such as the iPad and the Android tablet. Because the size and form factor is relatively new, early and low fidelity prototyping of these TUIs is crucial in getting the right design. The problem is that it is difficult for the average interaction designer to develop such physical prototypes. They require a substantial amount time and effort to physically model the tangibles, and expertise in electronics to instrument them. Thus prototyping is sometimes handed off to specialists, or is limited to only a few design iterations and alternative designs. Our solution contributes a low fidelity prototyping approach that is time and cost effective, and that requires no electronics knowledge. First, we supply non-specialists with cardboard forms to create tangibles. Second, we have them draw lines on it via conductive ink, which makes their objects recognizable by the capacitive touch screen. They can then apply routine programming to recognize these tangibles and thus iterate over various designs.