Fingerprint-inspired triboelectrific sliding sensor

Inspired by the structure of human fingerprint, a novel sliding sensor composed of four spiral and alternate electrodes is presented in this work. Based on triboelectric and electrostatic induction effects, four electrodes generate voltage signals one after another when an external object move across the surfacce. According to this mechanism, sequence of four signals can not only figure out sliding direction but also detect displacement and speed of the sliding object by calculating the number of signal valleys and corresponding time interval. The sensor, which is fabricated by carbon nanotube and polydimethylsiloxane (CNT-PDMS) composite electrode on elastomer substrate, has very good stretchability enabling its easy coverage on robot hand and detection of sliding motion on irregular surfaces.