A Liquid-Metal-Based Pressure Sensor With Adjustable Sensitivity Module

Liquid metal sensors are widely used in smart electronics, health monitoring, and smart engineering. Usually, the liquid metal sensor with a single structural design has only one measurement performance, which cannot meet the different measurement requirements, such as sensitivity requirements and range requirements. In this study, we developed a liquid-metal-based flexible pressure sensor which can adjust its sensitivities by easily changing the control block. Through the lithography process, we fabricated a flexible pressure chip with a special structure. This structure allows the flexible chip to change the sensing performance by changing the compression area. On this basis, we select three different sizes of control blocks to change the sensing performance of the chip, and verify that the flexible chip has three different measurement sensitivities to satisfy different measurement requirements in practice. We installed a 50CrVA alloy steel shell to increase the measuring range of the pressure sensor. Furthermore, we use the Wheatstone electrical bridge to reduce the error caused by temperature. The pressure sensor has three measuring ranges of 20, 27, and 35 MPa. The pressure sensor has good linearity (5.4%–17.5%), low repetition error (2.4%–9.7%), and low hysteresis error (2.8%–5.3%). In addition, we also conducted application experiments on flexible chips and pressure sensors, which proved its practical application value.