Multiphysics Coupling Model of Flexible Multisensor System Based on MEMS Beam Structure

To meet the requirements of parameter testing under special environments, we conduct research on multiparameter integrated sensors. This article proposes a flexible multisensor system based on MEMS beam structures, which utilizes MEMS double-clamped beam and MEMS V-shaped beam to test two parameters of curvature and threshold temperature. Due to the interference between loading temperature and loading curvature during the testing of the multisensor system, a multiphysics coupling model of the system is established to analyze the mutual effect between the two sensors under the loading of temperature and curvature. Multiple sensors have been designed and fabricated on flexible liquid crystal polymers (LCPs) substrate, and the effects of substrate bending and temperature variation on sensor performance testing are characterized. The experimental results of the curvature sensor are consistent with the theoretical predictions within a maximum error of 6.81%. When the ambient temperature is below the threshold temperature, the curvature sensitivity is 5.2 MHz/m $^{-\text{1}}$ and the influence of ambient temperature on curvature testing is negligible. When the ambient temperature reaches the threshold temperature, the curvature sensitivity is 5.4 MHz/m $^{-\text{1}}$ The experimental results of the threshold temperature sensor agree with the theoretical predictions within a maximum error of 9.68% when substrate curvature varies. The resonant frequency offset of the substrate in a flat state is 350 MHz at the threshold temperature.