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 owing to its inherent flexibility and biocompatibility; however, its poor adhesion to the skin and excessive stiffness of 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 a thiol–ene reaction. The composite exhibits enhanced adhesion to both the skin and skull, high stretchability, and tunable stiffness ranging from 10 to over 200 kPa, enabling adaptability to the long-term monitoring of epileptic activity and other application scenarios. Moreover, the C-PBS/CNT composite elastomer demonstrated excellent self-healing performance owing to its 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 enable a precise analysis of cortical epileptic-activity propagation and provide an essential technological platform for the prediction and treatment of epileptic seizures, paving the way for next-generation wearable biomedical devices.