Biphasic Liquid Metal Composite for Strain Sensor with High Stretchability and Sensitivity

Abstract

Strain measurement is crucial for the safety and stability of engineering activities. With the increasing demand for sensors and large strain measurement in engineering monitoring, the study on the large strain measurement is deepening. However, the conventional strain sensors based on rigid conductive materials have limited flexibility and low stretchability, and the research of large strain and flexible sensors in engineering still lacks. In this work, a highly stretchable and sensitive flexible strain sensor based on liquid metal‐Nickle microparticles (LMN) composite is developed to detect large strain. The LMN composite, featuring uniformly dispersed Nickle microparticles within the liquid metal matrix, is deposited onto the elastomer Ecoflex base material.The LMN composite based‐sensor exhibits high sensitivity (GF = 16.14644 at strain of 200%), large stretchability (up to 200%) and low hysteresis. The theoretical relationship between the relative resistance changes and strain is derived, and the theoretical derivation is compared with experimental data to verify the accuracy of theoretical derivation. Additionally, the LMN composite based‐sensors can be used to detect pressure and bending signals in engineering. This work highlights the potential of LMN composite in broad applications and can facilitate the application of flexible sensing devices in engineering.