Current robot tactile sensors have shortcomings such as poor wearability and portability, as well as being unpleasant to be maintained and expanded. An expandable, fully compliant capacitive tactile sensor is presented to counteract these shortcomings, which can be used as bio-inspired skin. The structure is designed with two kinds of expandable arrays, the 12×12 square tactile sensing array and the hexagon tactile model. The pressure-sensitive unit is constituted of carbon black filled silicone rubber uniformly as the elastic dielectric of the capacitive sensor, polyimide film as the flexible substrate, as well as silver conductive adhesive and metal film as the flexible parallel-plates of capacitor. In addition, the working principle and the structure design of the capacitive flexible tactile sensor are introduced, and also the wireless signal acquisition and processing systems of two corresponding capacitive arrays are proposed. The experiment results indicate that the fully compliant capacitive sensing array and capacitive signal extraction system has good stability and sensitivity to be used as artificial skin to achieve tactile perception.
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