Tactile sensing arrays for humanoid robots

Development of robots capable of operating in unstructured environments or intended to substitute for man in hazardous or inaccessible environments, demands the implementation of sophisticated sensory capabilities, far beyond those available today. In this regard, the development of tactile sensors is one of the key technical challenges in advanced robotics and minimal access surgery. In this work we present arrays of 'taxels' (tactile elements) which will be placed on the distal phalange of the humanoid robot in our lab. We present two different designs and implementations. In the first one, microelectrode arrays(MEAs) of 32 elements, with 1 mm center to center distance, have been designed. The taxel is implemented by epoxy-adhering the sensing material (piezoelectric polymer film of PVDF-TrFE) on a microelectrode. Each taxel is intended to be used as an extended gate of an FET (external to the chip); the taxel collects the charge/voltage generated, as consequence of the applied stress, on the deposited piezoelectric polymer film (i.e. the extended gate itself). The second design and implementation integrates both the taxels array and the FET devices, on the same silicon die.