3D-printed auxetic sensors promise leap in wearable electronics

A research team from Seoul National University of Science and Technology, led by Mingyu Kang and Dr. Soonjae Pyo, has developed a novel 3D-printed tactile sensor platform based on auxetic mechanical metamaterials (AMMs). These materials exhibit a negative Poisson’s ratio, meaning they contract inward under compression, which concentrates strain and enhances sensitivity. Using digital light processing (DLP)-based 3D printing, the team fabricated cubic lattice structures with spherical voids that improve sensor performance by increasing sensitivity, maintaining stability, and minimizing crosstalk. The sensors operate in capacitive and piezoresistive modes, with the latter utilizing a carbon nanotube coating to detect resistance changes under load. The researchers demonstrated the technology’s potential through applications such as tactile arrays for spatial pressure mapping and wearable smart insoles capable of monitoring gait patterns and detecting pronation types. Unlike conventional porous structures, the auxetic design prevents lateral expansion, making the sensors more wearable and less prone to