Flexible, self-powered and multi-functional strain sensors comprising a hybrid of carbon nanocoils and conducting polymers

The development of flexible and stretchable multi-functional sensors addresses the requirements for applications in fields of electronic skins, artificial intelligence, and health/structure monitoring. Here, we fabricated a novel self-powered strain-temperature dual-functional sensor based on composite films of carbon nanocoils (CNCs) and a conductive elastomeric blends of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and waterborne polyurethane (WPU). Owing to the high stretchability of helical-structured CNCs, high elasticity of WPU and multiple interfacial contacts between the conducting constitutes, the sensor exhibited a broad strain detection range of 0-50% and a high sensitivity with gauge factor (GF) of 25. Based on the Seebeck effect arising from the conducting polymer of PEDOT:PSS, the sensor-enabled both detection of temperature changes and strain deformations at a self-powered circumstance. To demonstrate its practical application as a wearable device, the senor was directly attached to the human skin. It not only detected subtle human motion and strain stimuli but also could distinguish the stimuli from either a warm or a cold objective by telling the difference in their temperature signals. This is the first time that the CNC-based composites are developed for use as a multi-functional sensing medium. Our self-powered strain-temperature dual-functional sensor demonstrates great potential in flexible devices and e-skin applications.

Automated summary

The development of a self-powered strain-temperature dual-functional sensor based on carbon nanocoils and conductive elastomeric blends shows potential for broad strain detection range, high sensitivity, and practical application in monitoring human activities and temperature changes on the skin.