Direct Shear Stress Mapping Using a Gallium Nitride LED-Based Tactile Sensor.

An experiment was performed to calibrate the capability of a tactile sensor, which is based on gallium nitride (GaN) nanopillars, to measure the absolute magnitude and direction of an applied shear force without the need for any post-processing of data. The force's magnitude was deduced from monitoring the nanopillars' light emission intensity. Calibration of the tactile sensor used a commercial force/torque (F/T) sensor.

Ultrathin Tactile Sensors with Directional Sensitivity and a High Spatial Resolution.

An ultrathin tactile sensor with directional sensitivity and capable of mapping at a high spatial resolution is proposed and demonstrated. Each sensor node consists of two gallium nitride (GaN) nanopillar light-emitting diodes. Shear stress applied on the nanopillars causes the electrons and holes to separate in the radial direction and reduces the light intensity emitted from the nanopillars.