UCLA

The conventional magnetoelastic effect describes the variation in magnetic flux density of certain materials under mechanical pressure within the megapascal range. In this study, we introduce porous microstructures into a soft magnetic system, resulting in an enhanced magnetoelasticity, characterized by a counterintuitive increase in magnetic flux density with the application of subtle mechanical pressure. This phenomenon, termed the structure-induced positive magnetoelastic effect, is attributed to the stress-induced redistribution of micromagnets within the porous, soft system, which exhibits a low Young’s modulus and near-zero Poisson’s ratio behavior. The technological impact of this discovery is demonstrated in its application to acoustic sensing and voice recognition, overcoming the low-pressure detection limits of current platform technologies. This breakthrough holds substantial potential for ultrasensitive pressure detection, with wide-ranging applications in extracting subtle physiological information.