A tensorial shear stress sensor based on light-emitting GaN nanopillars

Abstract

A force sensor capable of detecting both the magnitude and direction of the shear stress is proposed and demonstrated. The structure is based on an array of gallium nitride (GaN) light-emitting nanostructures and an off-the-shelf imager. The directional sensitivity originates from symmetry breaking of the nanostructures. Only a common bias is required for all GaN elements, making two-dimensional mapping of the stress relatively simple. As the stress sensing relies only on differential measurements, no stringent uniformity requirement across the sensor array is necessary.