The research objective of this project is to test the hypothesis that the physics behind a new class of piezo-resistive nano-composites can be modeled using a novel tunneling/percolation model, and that the resultant sensors can be used for sensing large strains in biological tissue. This hypothesis will be tested using various innovative characterization and modeling approaches applied to an advanced nano-nickel conductive composite. Focused-ion beam and high-frequency impedance analysis of quantum junctions will unveil the nano-level structure while new nano-indentation techniques will extract quantum tunneling parameters for elastomeric polymers that provide candidate matrix materials. Finite element analysis will be used to track evolution of nano-junctions under strain, and feed a dynamic percolation model that will capture the piezo-resistive effect. The resultant state-of-the-art model will guide sensor design for employment in the area of biological soft tissue. Two biological studies will form the vehicle for application and validation of the scientific investigation: characterization of ligament response in human spines, and tracking of strain on athletes.
If successful, the project will enable important insights into the material behavior of human tissue. Additionally, the results will unlock the door to understanding a broad class of novel nano-composite sensor materials that may be developed. The proposed wide-range sensors will provide flexible and inexpensive measurement of the nonlinear, large-strain motions of materials that have previously been difficult or impossible to characterize. Potential applications in athletics, human-machine interfaces, virtual reality, biomechanics, and medicine are envisioned. Furthermore, the project will accomplish these goals while providing a strong educational focus on mentoring undergraduate and women engineering students.
