A bioinspired hydrogen bond-triggered ultrasensitive ionic mechanoreceptor skin

Abstract

Biological cellular structures have inspired many scientific disciplines to design synthetic structures that can mimic their functions. Here, we closely emulate biological cellular structures in a rationally designed synthetic multicellular hybrid ion pump, composed of hydrogen-bonded [EMIM+][TFSI-] ion pairs on the surface of silica microstructures (artificial mechanoreceptor cells) embedded into thermoplastic polyurethane elastomeric matrix (artificial extracellular matrix), to fabricate ionic mechanoreceptor skins. Ionic mechanoreceptors engage in hydrogen bond-triggered reversible pumping of ions under external stimulus. Our ionic mechanoreceptor skin is ultrasensitive (48.1-5.77 kPa(-1)) over a wide spectrum of pressures (0-135 kPa) at an ultra-low voltage (1 mV) and demonstrates the ability to surpass pressure-sensing capabilities of various natural skin mechanoreceptors (i.e., Merkel cells, Meissner's corpuscles, Pacinian corpuscles). We demonstrate a wearable drone microcontroller by integrating our ionic skin sensor array and flexible printed circuit board, which can control directions and speed simultaneously and selectively in aerial drone flight.