Mechanosensory neuron implemented by a single freestanding epitaxial SrTiO3 capacitor

Biological mechanoreceptors convert tissue strain into distinct spike trains. In contrast, their soft electronic counterparts still rely on discrete components for sensing, preprocessing, and neuronal firing. Here, we integrate these functional components into a single and scalable device by combining mechano-electric transduction and volatile threshold switching within an Ag/freestanding epitaxial SrTiO3/Pt membrane laminated onto a flexible polyethylene naphthalate substrate. Tensile strain (0–2.6%) lowers Ag⁺ migration energy and reduces the switching voltage from 1.04 to 0.24 V. Under constant bias, the spike frequency increases by more than two orders of magnitude, enabling tunable, self-oscillating ‘neurons’ operating below 100 pJ per spike, comparable to biological mechanoreceptors and ~25× more efficient than current flexible sensors. The device maintains its full functionality after over 400 bending cycles, demonstrating its potential as a mechanically programmable, ultralow-power building block for next-generation electronic skins, soft robotics, and bio-integrated prosthetics.