A Stress-Dispersed MEMS Bionic Turbulence Sensor With Enhanced Reliability

This article presents the design methodology, fabrication process, and experiment evaluation of a bionic vector turbulence sensor with a combined stress-dispersed crossbeam and bullet-shaped package structure for turbulence measurements in harsh marine environments. The sensor is primarily designed based on the optimized reliability using the finite-element method. Specifically, a stress-dispersed cilium-beam sensitive structure with excellent mechanical robustness is developed by optimizing the stress concentration regions on the beam. Compared to traditional sensitive elements, a significant decrease in concentrated stress can be achieved, and the failure limit considerably increases. The crossbeam microstructure is fabricated based on the microelectromechanical systems (MEMSs) technology, and piezoresistors are formed on the beams. The bullet-shaped package structure achieves high-pressure resistance by employing a double water-tightness approach. In particular, the design of open front fairwater limits excessive displacement of cilium to avoid structural destruction due to overload. The calibration results indicate that the sensitivity of the sensor reaches $1.06\times 10^{-{2}}$ ( $\text {V}\cdot \text {m}\cdot \text {s}^{{2}}$ )/kg. A systematic evaluation of the sensor’s marine environment adaptability, reliability, and stability is conducted to validate the robust performance of the designed sensor. Furthermore, a field test is performed in a real environment. The obtained results suggest that the reported sensor exhibits excellent environmental adaptability and reliability. The success of this investigation paves the way for the technology maturity and engineering application of the MEMS turbulence sensor.