SIGNAL (programming language)

Quantum mechanics

Voltage

Engineering

Neuroscience

Polymer chemistry

Biology

Somatosensory system

Materials science

Sensory system

Computer science

Current (fluid)

Thermodynamics

Physics

Nanotechnology

Organic chemistry

Self-healing hydrogels

Triboelectric effect

Composite material

Ionic bonding

Chemistry

Programming language

Optoelectronics

Electrical engineering

Science

The human somatosensory network relies on ionic currents to sense, transmit, and process tactile information. We investigate hydrogels that similarly transduce pressure into ionic currents, forming a piezoionic skin. As in rapid- and slow-adapting mechanoreceptors, piezoionic currents can vary widely in duration, from milliseconds to hundreds of seconds. These currents are shown to elicit direct neuromodulation and muscle excitation, suggesting a path toward bionic sensory interfaces. The signal magnitude and duration depend on cationic and anionic mobility differences. Patterned hydrogel films with gradients of fixed charge provide voltage offsets akin to cell potentials. The combined effects enable the creation of self-powered and ultrasoft piezoionic mechanoreceptors that generate a charge density four to six orders of magnitude higher than those of triboelectric and piezoelectric devices.

Piezoionic mechanoreceptors: Force-induced current generation in hydrogels