Study of Textile Input Interface Design and Operability by Using Capacitance Sensing

This study proposes a fabric-type input device that provides mobility by using a weighted value based on the movement velocity between 16 individual capacitors com- posed of conductive textile. In addition, the proposed device measures the rate of change of dielectric permittivity based on pressure or touch and provides the function like a mouse. A capacitor is composed of a conductive material (37 mΩ/sq), where a coating of copper and nickel is applied to polyester, and the area of the capacitor is 10 mm (W)× 10 mm (L). The lower layer is composed of non-conductive fabric having a thickness of 1.36 mm, and the interval between each capacitor is 8 mm with four columns and four rows. Before touch, the capacitance was 120 pF and after touch, the capacitance increased up to 820 pF. In a monitor having a resolution of 1920×1080, it was observed that the aver- age mobility of a mouse was 60.89 mm and the standard deviation was 0.92 mm, while for a fabric interface, the average mobility was 965.77 mm and the standard deviation was 7.37 mm.