Biphasic liquid metal composite for strain sensor with high stretchability and sensitivity

Strain measurement plays significant roles in the safety and stability of engineering activities. With the increasing demand for sensors and the large strain measurement in the field of engineering monitoring, the study on the large strain measurement is constantly deepening. However, the conventional strain sensors based on rigid conductive materials have limited flexibility and low stretchability, and the research of the large strain and flexible sensors in engineering is still lacked. In this work, a highly stretchable and sensitive flexible strain sensor based on liquid metal‐Nickle microparticles (LMN) composite is developed to detect the large strain in engineering. Uniform dispersion of Nickle microparticles in LM matrix is achieved by continuously stirring until they are mixed totally. The elastomer Ecoflex is employed as the base material. The LMN composite is deposited onto the elastomer Ecoflex base material, then the LMN composite‐based strain sensor is produced. In this study, 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 relative resistance is compared with experimental relative resistance to verify the accuracy of theoretical derivations. In addition, the LMN composite can also be considered as a sensor to detect pressure and bending signals in engineering. This work highlights the potential of LMN composite in broad applications and can facilitate the realization of flexible sensing devices under engineering applications. This article is protected by copyright. All rights reserved.