Self-healing and Highly Adhesive Conductive Polydimethylsiloxane-Based Elastomers for Chronic Epilepsy Monitoring

Abstract

Flexible substrate materials with high adhesion, high stretchability, and low impedance are essential to ensure long-term stable acquisition of electrophysiological signals with less tissue inflammation. Polydimethylsiloxane is a promising candidate due to its inherent flexibility and biocompatibility, however, its poor adhesion to skin and excessive stiffness for tissue interfaces limit its application in this field. To address these challenges, we developed a flexible electrode system based on crosslinked block polyborosiloxane and carbon nanotube (C-PBS/CNT) elastomers carrying hydroxyl groups through thiol-ene reaction. The composite exhibits enhanced adhesion to both skin and skull, high stretchability, and tunable stiffness ranging from 10 to over 200 kPa, enabling adaptability to long-term monitoring of epileptic activity and other application scenarios. Moreover, the C-PBS/CNT composite elastomer demonstrated excellent self-healing performances due to the dynamic boronate ester and hydrogen bonds. The packaged C-PBS/CNT electrode demonstrates low impedance for efficient multi-channel acquisition of epileptic activity under humid conditions. These innovations not only enable a precise analysis of cortical epileptic-acitivity propagation but also provide an essential technological platform for the prediction and treatment of epileptic seizures, paving the way for next-generation wearable biomedical devices.