Development of Weighing Systems with Improved Dynamic Range Using High-Resolution Resonant MEMS Strain Sensors

The application of high-resolution MEMS strain sensors based on micromechanical resonators fabricated with wafer-level vacuum packaging to the construction of large dynamic range weighing systems is explored. Resonant sensors with sub-nano strain resolution are adopted to build a load cell prototype using a standard aluminum structure normally utilized in commercial weighing systems. A differential strain measurement configuration is implemented with two sensors oriented at 90° between them and fabricated on the same chip for temperature compensation. The load cell equipped with the resonant MEMS sensors shows an excellent dynamic range of 108 dB, effective temperature compensation and good weight measurement reproducibility.