A Flexible Pressure/Bending Bimodal Sensor for Hand Movements Monitoring

Flexible force-sensitive devices capable of measuring and distinguishing multiple mechanical stimuli are major components in the development of robot tactile applications. Herein, a pressure/bending bimodal flexible tactile sensor is proposed for hand movements monitoring. The sensor consists of a pressure sensing unit that is insensitive to bending and a bending sensing unit that is insensitive to pressure. The sensor exhibits differentiated working mode under pressure load and bending deformation. The pressure and bending sensitivity can reach up to 0.094 kpa-1 and 0.138 rad-1, respectively. When the sensor is subjected to pressure, the maximum crosstalk in the bending sensing module accounts for up to 19.6% of the pressure response. When subjected to bending, the maximum crosstalk in the pressure sensing module accounts for 17.6% of the bending response. This indicates that the dual mode outputs indeed accurately distinguish between pressure and bending stimuli. The sensor also shows good mechanical stability in repeated pressing/bending test over 1000 times. Finally, a smart glove with five bimodal sensors integrated at the knuckles is fabricated to demonstrate its applications in tactile perception, gesture, and grasp recognition.