Injectable Double-Network Hydrogel as Soft Bioelectronics for Epileptic Discharge Monitoring Via Engineered Two-Dimensional-Materials

Abstract

Single-component hydrogels often grapple with the formidable challenge of meeting multifaceted capability requirements essential in practical applications, including conductivity, adhesiveness, injectability, and resistance to stretching and bending. In response, we harness a double-network hydrogel (DNH) strategy, augmenting it with engineered two-dimensional-material transition metal boride (MBene) as an enhancer. This innovative strategy enables the creation of MB-DNH hydrogel, showcasing favourable injectability, conductivity, robust adhesion to brain tissue, and resilience against bending and stretching. Consequently, it empowers us to analyze and monitor epileptic abnormal discharges. Regarding conductivity, MB-DNH (0.24 ± 0.009 mS/cm) outperforms two single-network hydrogels (PEDOT: PSS and polyacrylamide), exhibiting enhancements of 0.84 and 25.6 folds, respectively. Regarding adhesiveness, MB-DNH excels, showing increments of 128.8% and 117.7%, respectively, compared to two single-network hydrogels. For mechanical capability, MB-DNH demonstrates favourable resistance to stretching and bending with relative standard deviation (RSD) values of 1.03% and 1.35%, respectively, following 50 stretching and 30 bending cycles. In practical applications, MB-DNH enables electroencephalogram (EEG) recording and monitoring of abnormal discharges in epileptic mice. We envision that this double-network hydrogel strategy, anchored by MBene, will substantially advance precise and efficient EEG recording, propelling progress in brain-machine interfaces and human-computer interaction.