Highly flexible, stretchable, durable conductive electrode for human-body-attachable wearable sensor application

Abstract

Flexible/stretchable electrodes based on conductive polymers are used in various fields, including wearable devices and human body sensors. However, the durability of flexible/stretchable electrodes is insufficient. In this study, a carbon nanotube (CNT) electrode layer was formed on a polydimethylsiloxane (PDMS) surface with a controlled precuring time using a simple spray-coating method. The electrical properties and durability of the CNT-based conductive polymers were evaluated. To evaluate the durability of the electrodes, bending, stretching, tribo, and scratch tests were performed. The degree of embedding of the CNT electrode layer on the PDMS surface differed according to the PDMS precuring time, which showed a difference in durability. The case in which the CNTs were coated at a precuring time of approximately 8–12 h had the best durability. It was verified that CNT-embedded PDMS electrodes fabricated under optimal conditions can be attached to the skin of human joints and used as human-body-attachable wearable sensors that measure changes in electrical resistance according to joint movement, resulting in excellent elasticity, durability, and performance.