Flexible Dual-Modal Piezoelectric Polymer Sensors: From Contact to Proximity Perception

The rapid development of artificial intelligence technology has imposed stricter requirements on the multimodal perception capabilities of intelligent robots. While flexible contact sensors based on piezoelectric materials have been widely used in robotic perception of external stimuli, their limited contact sensing capability hinders their application in human-machine interaction and other complex fields. The integration of noncontact or proximity perception capacity into piezoelectric sensors is an effective solution to greatly extend their potential. With the synergistic coupling between the piezoelectric effect of piezoelectric films and the electrostatic induction between a charged object and electrodes, dual-modal piezoelectric sensors were developed with sensing capacity in both proximity and contact processes. Furthermore, according to the charge response difference from both electrodes during noncontact and contact processes, both processes could be well recognized even in blind sensing conditions. Through proper circuit design, this dual-modal piezoelectric sensor was utilized for multiparameter quantization in impact tests, positioning of a target in both proximity and contact processes, and feedback control of a mechanical claw for grasping operation. This work provides a highly integrated solution for intelligent robotic perception systems, offering a feasible pathway for next-generation electronic skin design.