Charging Properties of Electrospun Poly(L-lactic acid) Submicrofiber Mat and Its Electrical Applications

Wearable pressure sensors have attracted significant attention owing to their potential applications in health monitoring and connectivity to internet-based apps. Polymers such as poly(vinylidene fluoride) have been used in sensors. However, being petroleum-derived materials, they do not decompose and remain in the soil when disposed. Poly(L-lactic acid) (PLLA) is a promising material because of its biodegradable nature and its derivation from plant-based materials. In addition, the electrospun PLLA fiber mat contains real charges and exhibits electromechanical properties. However, the detailed charging properties of the PLLA fiber mats remain unclear. Herein, the charge distribution of these fiber mat is presented, and a charging model of the fiber mat and a numerical model of the output charges from the fiber mats with electrodes are proposed. Additionally, the retention properties of the stored charges are determined using surface potential measurements at different temperatures. In addition, a self-power-generating touch sensor and mask-type sensor are developed using biodegradable materials produced from biomass. These studies contribute to the improvement in the charge properties of PLLA fiber mats and the resulting wearable biodegradable sensors.