Investigation of Touch Interfaces Using Multilayered Urushi Circuit

Urushi (Japanese lacquer) is a natural resin paint with electrical insulating capability. By using it as a base material and coating material for electronic circuits, it is possible to construct a circuit with an elegant appearance and feel. It is also possible to build a multilayered electronic circuit by using urushi as insulation layers. In this study, we investigate techniques to construct touch interfaces using a multilayered electronic circuit (urushi circuit). At first, we fabricated an urushi circuit with a touch electrode consisting of two layers. To improve its appearance, we fabricated urushi circuits in which all touch electrodes are arranged on the top layer and all wires are hidden in the bottom layer. Moreover, as an extension of the touch interface, we built a grid of touch electrodes that realizes two-dimensional touch sensing.