The objective of this NASA Phase II program is to develop and increase the Technology Readiness Level of multifunctional Metal RubberTM (MRTM
) materials that can be used as 1) large strain sensors, and 2) strain-insensitive electrical interconnects for aerospace systems and structures. The aerospace systems-level problem these materials would help solve is the inability of currently available metal-based sensors and wiring/interconnects to undergo the large strains and displacements associated with shape changes of inflatable, flexible and morphing structures. During Phase I, NanoSonic demonstrated the feasibility of the MRTM family of free-standing nanocomposite materials to serve as 1) electrically-conductive, low-modulus electrode wiring for a) large displacement mechanical actuators required to affect large shape changes, and b) embedded or attached electrical data buses that are not affected by strain, and 2) strain sensors capable of measuring very large strains to allow mapping of the deformation of adaptive structural components. During Phase I, NanoSonic also developed a first-principles physical model of electrical conductivity percolation in Metal RubberTM
, and performed experimental analysis to validate model assumptions. During Phase II, NanoSonic would work cooperatively with a large aerospace contractor to optimize material properties, upscale material production, and evaluate material performance under simulated space environmental conditions.