Low-temperature strain sensors based on integral molding cured CNTs/GNPs/PDMS composites with tensile and compressive strain responses, respectively

Abstract

The preparation of flexible materials as strain sensors for wearable devices with good mechanical and electrical properties at low temperatures is a major challenge. In this study, novel low-temperature strain sensors are fabricated based on the template method of integral molding cured CNTs/GNPs/PDMS composites. The one-piece molding process results in composites with excellent mechanical properties and environmental adaptability (temperature insensitivity, hydrophobicity, and humidity resistance). CNTs/GNPs/PDMS strain sensors that respond to tensile and compressive strains, respectively, can be obtained by changing only the shape of the template. They both offer a wide operating range, high gauge factors (GFs), and long-term reliability over the entire temperature range (−20–40 °C). At 20 and −20 °C, CNTs/GNPs/PDMS tensile and compressive strain sensors are used to monitor various human activities and human physical signals. This study provides a new promising strategy for the construction of future wearable devices for low-temperature condition applications.