PDMS-CNT composite for soft bioelectronic neuronal implants

This communication reports the detailed description of a technology for the manufacturing of stretchable and biointegrated neuronal implants based on carbon nanotubes (CNTs) and poly(dimethylsiloxane) (PDMS). An essential part of the proposed technology is the fabrication of PDMS-CNT composite materials which are characterized by their high level of biocompatibility, long-term biostability, outstanding tensile strength, high values of charge storage capacity, and non-Faradaic type of electrode processes. To fabricate the stretchable spinal cord implants from obtained PDMS-CNT composite materials, sophisticated casting metal molds were used. The mechanical, electrical and biological properties of PDMS-CNT composite materials and neuronal implants were characterized using multiple methods such as SEM, EDXRF analysis, tensile mechanical testing, cytotoxicity testing and cyclic voltammetry (CV). Furthermore, the functionality of stretchable spinal cord implants based on PDMS-CNT composite materials was studied using in-vivo tests on laboratory animals that indicated high efficiency of the proposed technology for monitoring and stimulation of neuronal activity in mammals.