Low-frequency ionic-electronic coupling for energy-efficient noise-resilient wireless bioelectronics.

Abstract

Wireless bioelectronics demand transduction strategies that are simultaneously sensitive, noise-resilient, and biologically safe. Conventional wireless sensors typically rely on dielectric capacitors with inherently low capacitance, necessitating operation at MHz frequencies. Such high-frequency coupling often introduces electromagnetic interference, tissue heating, and degraded signal fidelity in biological environments. Here we present a wireless low-frequency electrochemical sensing (WiLECS) platform that couples ionic dynamics with low-frequency LC resonant circuits. The device combines a biocompatible ion gel, composed of a choline-malate ionic liquid embedded in a chitosan matrix with functionalized Au nanoparticles, with a miniaturized LC antenna. Unlike conventional capacitive sensors, WiLECS employs piezo-driven ion redistribution to modulate the dielectric environment of the circuit, enabling sustainable wireless transduction below 1 MHz with high sensitivity and reliability. This approach directly bridges ionic dynamics and electronic resonance, allowing mechanical stimuli to be transduced into biologically safe low-frequency electronic signals. As proof of concept, we demonstrate real-time wireless blood-pressure monitoring in artificial arteries with atherosclerotic plaque, showing resolution of subtle pressure variations under clinically relevant conditions.