Development of an electronic skin based on piezoelectric porous PVDF nanospheres for robotic perception

Abstract

With the rapid advancement of robotics and human–robot interactions, electronic skins (e-skins) have demonstrated great potential in robotics. Notably, the development of the emerging field of piezoelectric sensors can unveil flexible e-skins. Herein, a new type of e-skin based on piezoelectric porous polyvinylidene fluoride (PVDF) nanospheres for robotic perception has been reported. We have employed an elegant method based on the thermodynamics of polymer solutions to induce porosity in PVDF nanospheres. By adding a defined amount of water, chosen from the ternary phase diagram of PVDF/water/dimethylformamide (DMF), porous PVDF nanospheres have been synthesized. Piezoelectric measurements along with finite element method (FEM) simulations have confirmed that porous nanospheres generate a higher output voltage compared to dense ones. It is realized that the fabricated e-skin using porous PVDF nanospheres is thin, flexible, and durable. Besides, it can efficiently distinguish finger pressing. At the final stage, the e-skin integrated with electronic circuits and a microcontroller has been able to successfully control the grasp action of a robotic hand. Consequently, it can be envisioned that the proposed e-skin has great potential for future applications in robotics and human–robot interactions.