Stretchable conductor from oriented short conductive fibers for wiring soft electronics

We developed the stretchable wiring made from oriented short conductive fibers and applied it to a stretchable pressure sensor. The short fibers were mechanically oriented on an elastic substrate/film across the long wiring axis of wiring. The stretchable wiring with 5 mm in width had 17.0 Ω in initial resistance per 1 cm in length and the change in its resistance was only 214 % at 100 % elongation. Even if the wiring is stretched in the long axis direction, the short fibers form junctions with other fibers, thereby retaining their electric conductivity. A stretchable pressure sensor sheet, which is sensitive to pressure in the vertical direction and insensitive to elongation in the horizontal direction, was also successfully developed using the stretchable wiring and elastomer films. These sensor cells sensitively measured the pressure up to ca. 64 kPa. This sensor sheet was demonstrated as a shoe insole pressure sensing system and the sensor system could detect a pressure distribution from soles to adapt to its deformation.