Novel conductive PEDOT:DBSA hydrogels with tuneable properties for bioelectronics

Conductive hydrogels represent a promising class of novel materials to interface the human body with electronics; however, there is still a high demand for hydrogels that would truly meet the conductivity requirements for efficient signal transmission between the tissues and the device. To address this demand, herein we report the preparation of a novel pure conductive hydrogel based on PEDOT:DBSA at room temperature; thus, we offer an efficient alternative to the commonly used PEDOT:PSS, whose biocompatibility was proven to be limited. With thorough characterization, this work also contributes towards a better understanding of the relationship between the hydrogel structure and electrical properties. The mechanical strength of the novel hydrogel network is tuneable and can be easily tailored to the needs of a given application. Together with an exceptionally low value of Young's modulus, this material provides mechanical properties matching those of soft tissues. Biocompatibility tests confirmed excellent compatibility with murine endothelial cells. The total conductivity of the hydrogel is sufficient for cell-targeted bioelectronic applications, such as cell stimulation; moreover, low impedance was determined at 1 Hz, suggesting that the PEDOT:DBSA hydrogel might offer a truly functional interface between a biological tissue and an electronic device.