Topological Design of Strain Sensing Nanocomposites

High-performance piezoresistive nanocomposites have attracted extensive attention because of their significant potential as next-generation sensing devices for a broad range of applications, such as monitoring structural integrity and human performance. While various piezoresistive nanocomposites have been successfully developed using different material compositions and manufacturing techniques, current development procedures typically involve empirical trial and error that can be laborious, inefficient, and, most importantly, unpredictable. Therefore, this paper aims to propose and validate a topological design-based methodology to strategically manipulate the piezoresistive effect of nanocomposites to achieve a wide range of optimized strain sensitivities without changing the material system. In particular, this work designed patterned nanocomposite thin films with stress-concentrating and stress-releasing topologies. The strain sensing properties of the different topology nanocomposites were characterized and compared via electromechanical experiments. Those results were compared to both linear and nonlinear piezoresistive material model numerical simulations. Both the experimental and computational results indicated that the stress-concentrating topologies could enhance strain sensitivity, whereas the stress-releasing topologies could significantly suppress bulk film piezoresistivity.