Multimodal Characterization Method for Metamaterials with Tunable Mechanical Stiffness and Electrical Resistivity

Multifunctional material systems present significant opportunities across various engineering fields by enabling the tailored modification of mechanical properties through unit cell geometry design. This study introduces a multimodal characterization method for complex material systems, applied to a prototype model structure inspired by 2D auxetic unit cells, which feature four distinct states of mechanical stiffness and electrical resistivity. Initially, simulations are conducted to engineer the structural behavior. Experimental validation is achieved through multimodal testing of a 2.5D‐printed geometry made from conductive PLA. Characterization reveals changes in force, torque, and resistance across the four states, which are not distinctly separable but rather manifest as transition areas. Nevertheless, identifiable points of interest marking state changes could be detected. Furthermore, the measured curves demonstrate a value shift throughout cyclic loading, suggesting potential damage evolution. Additionally, the resulting moments provide insights into contact order and damage initiation. However, both phenomena warrant further investigation with an expanded sample size and more refined measurement techniques. Overall, this research bridges material design and practical measurement, emphasizing the need for innovative characterization methods in complex multifunctional systems.