Mechanically Robust Soft Bioelectronics: Towards Conductive Elastomers with a Low Percolation Threshold

Conductive polymer-elastomer composites have been proposed as an alternative to the metals conventionally used for bioelectronic devices. Being softer and more stretchable than metals such as platinum and gold, they can mitigate the adverse effects associated with mechanical mismatch and fatigue failure. Such composites are conventionally made by embedding conductive polymer (CP) particles inside an elastomeric matrix. However, to achieve such a structure, a high CP loading that reaches a percolation threshold is required. High percolation thresholds lead to the degradation of mechanical properties. This study presents an alternate approach designed to reduce CP content while maintaining conductivity through the matrix. A PEDOT:PSS composite was produced by filling a CP aerogel with polydimethylsiloxane (PDMS). This approach successfully formed a robust and conducting material, with only 1.8wt% CP. However, the composite displayed plastic deformation behaviour limiting electrical performance under strain. Potential improvements lie within modification of the PEDOT:PSS/PDMS interface.