Sensors for the measurement of shear stress and shear strain-a review on materials, fabrication, devices, and applications

Shear sensors are used for measuring shear stress and shear strain in solid bodies when mechanical forces are applied. For the preparation of these sensors, researchers reported innovative materials either alone or in the form of blends, alloys, and composites. Shear sensors are not easily available for purchase, therefore, this review focuses on the working principles of various kinds of shear sensors being explored by researchers. Several technologies and materials are used, such as piezoelectric materials, piezoresistive materials, Fiber Bragg Grating, capacitive sensing, and structural colors. This article also looks at fabrication-based challenges that restrict the commercial use of shear sensors. A variety of shear sensor devices are evaluated for measuring shear stress/strain for many different applications such as health monitoring and biomedical, robotics, and or fracture in materials.