Wireless, battery-free, and real-time monitoring of water permeation across thin-film encapsulation

Long-term bioelectronic implants necessitate stable, hermetic encapsulation. Water and ion ingress are challenging to quantify, particularly in miniaturized microsystems over time. This research introduces a wireless, battery-free, flexible platform utilizing backscatter communication and magnesium (Mg)-based microsensors for real-time monitoring of water permeation through encapsulation. Water ingress corrodes the Mg sensor, shifting the sensing circuit's oscillation frequency. In vitro and in-tissue testing validates the platform's functionality, robustness, and accuracy, highlighting its potential for in situ real-time monitoring of implanted bioelectronics.

Massimo Mariello, James Daniel Rosenthal, Francesco Cecchetti, Mingxiang Gao, Anja K. Skrivervik, Yves Leterrier, Stéphanie P. Lacour