Sensing touch using resistive graphs

In early design, instrumenting an object with touch sensing capability, especially one with complex surface geometry, can be problematic. In this paper, we show how resistive graph patterns--or resigraphs--can be used to quickly fabricate multi-touch sensors tailored to an object's shape. In very early ideation, resigraphs can be drawn using conductive ink. In later refinements they can be silk-screened or laser cut from off-the-shelf materials. A resigraph uses a commonly available microprocessor (e.g. Arduino), re-quires only three wires, and enables touch input on non-planar and non-developable surfaces.