Performance Enhancement of Piezoresistive Tactile Sensor Based on Mechanical Metamaterial with Negative Poisson's Ratio

This work proposes a piezoresistive tactile sensor based on a metamaterial with a negative Poisson's ratio, utilizing a more cost-effective and straightforward method compared to previous processes for fabricating microstructures. To demonstrate the impact of negative Poisson's ratio on piezoresistive sensor performance, comparison structures with a positive Poisson's ratio are designed, manufactured, and tested. The metamaterial-based sensor exhibits a high sensitivity at low pressures, which is 2.8 times higher than that of a body-centered cubic structure and 10 times higher than a simple cubic structure. Additionally, the fabricated sensor demonstrates excellent flexibility and minimal physical interference due to the integration of flexible electrodes and substrates. The sensor shows potential for various applications, including wearable devices, which have recently gained significant attention.