Abstract: A smart skin system includes tactile sensors that mimic the functions of human skin by sensing pressure, vibration and humidity simultaneously and generate electric signals as a result thereof; and a machine learning assisted data processor that interprets the electric signals from the sensors and quantitively perceives the stimulation in terms of pressure, vibration, and environmental humidity. The sensor structurally comprises (1) a single-ion conducting electrolyte, which provides contact electrification, serves as a hygroscopic layer and produces DC hygroelectric signals in response to humidity, (2) a gold electrode and (3) a separatable aluminum electrode as a counter triboelectrification layer that produces AC triboelectric signals in response to contact.

Abstract: A switchable triboelectric nanogenerator (s-TENG) which obtains energy by utilizing the electrostatic potential between water droplets and frictional surfaces. The s-TENG device includes an ITO film substrate as an electrode, a SU-8 mold grid located on the ITO film substrate and forming an array of air gaps as an air breakdown region, and a FEP film on the SU-8 mold grid as the surface of the friction layer. A water source is variably positioned at a distance from and at an angle to the s-TENG device so that water droplets contact the friction layer, so that direct current is obtained without the use of a rectifier due to electrostatic induction causing break down in the air breakdown region of the SU-8 mold grid.