Patent ID: 9052775
Filing Date: 2015-06-09
Classification: G01L,G06F

Abstract:
1. A tactile sensor that senses a normal load and a shear load as applied from an external source, the sensor comprising: a first layer having a first top surface and a first bottom surface, wherein the first layer comprises an optically reflective region, an optically absorptive region, and a boundary between the optically reflective region and the optically absorptive region; an optically transparent layer having a second top surface and a second bottom surface, wherein the second top surface of the optically transparent layer is bonded with the first bottom surface of the first layer; a first light emitter; a second light emitter; a first light detector; and a second light detector; wherein the optically transparent layer compresses due to the normal load; wherein the optically reflective region of the first layer is centered above the first light emitter and the first light detector; wherein a side of the boundary between the optically reflective region and the optically absorptive region is laterally displaced relative to the second light emitter and the second light detector from a position above the second light emitter and the second light detector due to the shear load; wherein the first light emitter emits light that traverses through the optically transparent layer towards the first layer, the optically reflective region of the first layer reflects the light from the first light emitter incident thereupon as reflected light from the first light emitter, the reflected light from the first light emitter traverses through the optically transparent layer towards the second bottom surface, and the first light detector detects the reflected light from the first light emitter and measures a first intensity of the reflected light from the first light emitter; wherein the first intensity changes due to compression of the optically transparent layer and the first intensity is indicative of the normal load applied to the first top surface of the first layer; wherein the second light emitter emits light that traverses through the optically transparent layer towards the first layer, the optically reflective region of the first layer reflects the light from the second light emitter incident thereupon as reflected light from the second light emitter, the reflected light from the second light emitter traverses through the optically transparent layer towards the second bottom surface, and the second light detector detects the reflected light from the second light detector and measures a second intensity of the reflected light from the second light emitter; and wherein the second intensity changes due to lateral displacement of the side of the boundary and the second intensity is indicative of the shear load applied to the first top surface of the first layer.