A 14.39ppm/kPa Stress Sensor with Low Temperature-drift and High Linearity for turbulence Stress

In the analysis and calculation of turbulent flow, the stress generated by the fluid needs to be accurately measured by sensors. In this research, a mechanical stress sensor was developed based on standard 180nm CMOS technology for real-time measurement of stress. The main contributions of this study include the following: 1) The temperature-compensated RC oscillator circuit changes mechanical stress-induced chip deformation into a frequency output. When the temperature was changed from -40°C to 120°C, the oscillator frequency only changed to 0.303Hz/ °C. 2) No complicated calibration and complicated measurement equipment are required. The chip area does not exceed 0.569 mm2. Moreover, the power consumption does not exceed 22.9 µW. 3) The average sensitivity measured by the chip is 14.39ppm/kPa, and the linear fitting curve's determination coefficient (R2) is 0.9983.