Mxene/Polydimethylsiloxane (PDMS) Based Implantable and Flexible Bioelectrodes for Neural Sensing

Research applications of neural sensing and muscle stimulation have been advanced by the development of bioelectrodes that are biocompatible, flexible and long lasting. The existing metallic made bioelectrodes exhibit extremely high electrochemical resistances that would interfere with the neural-electrode bridge and suffer from mechanical and immunological mismatch. Novel, flexible, implantable bioelectrodes based on MXenes (Ti
3
C
2
) and Polydimethylsiloxane (PDMS) composite are proposed. Mxenes possess the advantage of having metallic ultra-conductive transition metals consisting of large groups of carbides, nitrides, or carbonitrides, while PDMS has inherent biostability, flexibility and biocompatibility. In the current research, PDMS has been used as the supporting matrix for conductive fillers such as PMMA, PEDOT, and Mxenes. A series of characterization techniques were performed such as Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV) and mechanical testing. The average results of triplicate samples exhibited samples' bulk impedance of 0.913 kΩ, an impedance of 1.612 MΩ, at 1 kHz frequency and a conductivity of 1.41x10
^-4
S/cm, charge storage capacity of 0.056 mC/cm
²
and Young's modulus of 3.81 MPa.