Variable-stiffness metamaterials with switchable Poisson’s ratio
Elze Porte, Nidhi Pashine, Sree Kalyan Patiballa, Sophia Eristoff, Trevor L. Buckner, Rebecca Kramer‐Bottiglio
Abstract
Mechanical metamaterials are structured materials designed to exhibit unconventional mechanical responses. Most mechanical metamaterials have a single material response, but the ability to tune the intensity of a programmed response is useful to enhance the adaptability of the metamaterials to varying application requirements. This work presents variable-stiffness metamaterials (VSMMs) made from a thermally responsive, variable-stiffness Field's metal-silicone composite embedded in a soft silicone elastomer. We investigate VSMMs with different metamaterial structures and constituent material stiffness ratios, and we demonstrate that the VSMM properties are dominated by the embedded metamaterial in a stiff state and the host elastomer in a soft state. We showcase the utility of the VSMM by producing capacitive sensors that can switch between property states: high measurement sensitivity with limited deformations (<10%) or low sensitivity with large deformations (>60%).