Novel Approaches for Bio-inspired Mechano-Sensors

In this paper, we present novel approaches for building tactile-array sensors for use in robotic grippers inspired from biology. We start by describing the sense of touch for humans and we continue by proposing different methods to build sensors that mimic this behaviour. For the static tactile sense we describe the principles of piezoresistive materials, and continue by outlining how to build a flexible tactile-sensor array using conductive thread electrodes. An alternative sensor is further described, with conductive polymer electrodes instead. For the dynamic tactile sense, we describe the principles of PVDF piezoelectric thin films and how can they be used for sensing. The data acquisition system to process the information from the tactile arrays is covered further. We validate the proposed approaches by a number of applications: classifying a number of fruits and vegetables using only the haptic feedback during their palpation, recognizing objects based on their contact profile and detecting gentle contact and vibrations using the piezoelectric sensor. We conclude by showing what needs to be improved and addressed further to achieve human-like tactile sensing for robots.