Silicone/Carbon Nanotube Sheet Biofidelic Piezoresistive Sandwich Composites

Silicone-based biofidelic surrogates are used in many biomedical applications. Apart from mimicking the mechanical behavior of bodily tissues, there is an increasing requirement for these materials to be electrically conductive and piezoresistive to facilitate direct instrumentation. Carbon nanotubes (CNTs) have been extensively investigated as fillers to impart electrical conductivity and piezoresistivity to polymeric materials including silicone. In this paper, we fabricate, test, and characterize a two-part silicone/CNT sheet sandwich composites that exhibit conductivity, piezoresistivity, and biofidelic with mechanical properties corresponding to that of the white matter of human brain tissue. The electromechanical performance of the sandwich composite improves in subsequent loading after the core fracture during initial loading. Analytical models developed for discontinuous core sandwich structures are used to analyze and explain the experimental results. The results indicate the potential for using this discontinuous core biofidelic-piezoresistive sandwich nanocomposite for biomedical applications without deploying external deformation sensors.