Tailored Porous Conductive Elastomer Composites for Highly Sensitive Flexible Pressure Sensors over a Wide Range

Abstract

Developing high-performance pressure sensors with a wide detection range while retaining high sensitivity remains an enormous challenge. Herein, the porous conductive elastomer composite-based pressure sensors composed of natural rubber (NR) and multiwall carbon nanotubes (MWCNTs) were fabricated by the facile freeze-drying approach. The homogeneous dispersion of MWCNTs facilitates the formation of continuous conductive pathways within the NR matrix. When NR/MWCNTs conductive elastomer composites (CECs) were compressed, MWCNTs embedded in micropore walls can contact each other and strengthen the conductive pathways. Consequently, the as-obtained sensors exhibited a high sensitivity of 1.145 kPa^–1 over 0–480 kPa, a short response–relaxation time, and an excellent reversibility and stability. In addition, the sensors can effectively detect and capture subtle and large human movements such as wrist, elbow, knee bending, and even pulse. Furthermore, the sensors can be assembled and integrated with a glove to achieve remote gesture recognition and sports training monitoring. The designed NR/MWCNTs CECs-based pressure sensors hold great promise for integration into flexible wearable electronics.