Piezoresistive Nano-composite Sensors for Wide-range Strain: Applications in Biological Soft Tissue

该项目的研究目标是验证以下假设：一类新型压阻纳米复合材料背后的物理原理可以用一种新的隧道/渗透模型来建模，并且由此产生的传感器可以用于感应生物组织中的大应变。这一假设将通过应用于先进纳米镍导电复合材料的各种创新表征和建模方法进行测试。聚焦离子束和量子结的高频阻抗分析将揭示纳米级结构，而新的纳米压痕技术将提取弹性体聚合物的量子隧道参数，从而提供候选基质材料。有限元分析将用于跟踪纳米结在应变下的演变，并提供一个动态渗透模型，以捕捉压阻效应。由此产生的最先进的模型将指导传感器设计在生物软组织领域的应用。两项生物学研究将为科学研究的应用和验证提供载体：人类脊柱韧带反应的表征，以及运动员应变的跟踪。如果成功，该项目将使人们对人体组织的物质行为有重要的了解。此外，这些结果将为理解可能开发的新型纳米复合传感器材料打开大门。提出的宽量程传感器将提供灵活和廉价的测量非线性，大应变运动的材料，这是以前很难或不可能表征。在体育、人机界面、虚拟现实、生物力学和医学领域的潜在应用被设想。此外，该项目将实现这些目标，同时提供强大的教育重点，指导本科生和女工程专业学生。

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.