Simple and efficient pressure sensor based on PDMS wrapped CNT arrays

Abstract

Pressure sensors are critical components in the development of electronic skin for broad applications in healthcare monitoring and clinical diagnosis. Producing an inexpensive, sensitive, stable pressure sensor, however, remains a long-term work in progress. Here, we designed and fabricated a simple but efficient pressure sensor based on PDMS wrapped free standing CNT arrays. In contrast to regular conductive films made by dispersed nanomaterials, CNT arrays are naturally crooked and interconnected with numerous tunable contact points, resulting in a highly sensitive and stretchable sensor. The pressure sensor also exhibits rapid response and recovery times of less than 26 and 57 ms, respectively. Even after 8000 test cycles, the amplitude of the current change shows no observable fluctuations, demonstrating the sensor's strong reliability. With its high flexibility and low weight, the pressure sensor can be comfortably attached to the skin for monitoring critical physiological measurements such as radial artery pressure and respiratory rate. Furthermore, this work provides a new option to design various device by using carbon-based materials without the problem of stacking.