RootCap: Touch Detection on Multi-electrodes using Single-line Connected Capacitive Sensing

Abstract

In designing interactive products, it is important for designers to test the product's usability by manufacturing its shape and interface iteratively through rapid prototyping. The goal of our research is to provide the designers with an additional touch sensing method for rapid prototyping interactive products with flat, curved, or flexible surface. In this paper, we present RootCap, a capacitive touch sensing method that can detect a touch on a multi-electrode input surface while maintaining the characteristics of a single-line connection. The key concept behind realizing this goal is the imposition of unique capacitance on each electrode (including the capacitor connected to the touch electrode) branching from the single-line connection. Moreover, we developed a technique for creating a capacitor by printing silver nanoparticle ink on both sides of a sheet of paper, supporting designers in the creation of a multi-electrode input surface, on which each electrode has a unique capacitance.