A Practical Resonant MEMS Thermometer for Cryogenic Temperature Applications

In this paper, for the first time, a study on a resonant MEMS thermometer in cryogenic conditions is conducted, along with a comprehensive performance characterization. In brief, the device operates in different cryogenic temperature gradients across 210K to 4K with a controllable environment, where the characteristics in each region are thoroughly investigated. In addition to the temperature sensitivity, the noise performance, stability, and nonlinear behaviors are also ascertained. As a result, the device demonstrates an ultra-high-quality factor of up to 100,000 and a temperature resolution of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$228 \ \mathrm{uK} \sqrt{\text{Hz}}$</tex> at 4K, while the resonant frequency maintains a modest value of 94.12 kHz. These findings constitute a solid foundation for high-performance resonant MEMS sensors in extreme conditions, unveiling the potential applications of which in aerospace and quantum computing.