Ultra-High Sensitivity, Wide-Range Thermometry Based on High-Quality Microscale Diamond Resonators

Next-generation thermometry requires ultrahigh temperature sensitivity, precision, and microscale or nanoscale spatial resolution for bio-calorimetry, optoelectronic sensing, quantum science, energy storage, and thermal management of electronic devices. Current thermometry approaches based on thermocouple, resistive, and optical mechanisms suffer from various problems such as large volume, low resolution, high noise level, and narrow temperature range. Microelectromechanical system (MEMS) resonators hold great potential as thermometry due to the small size, batch fabrication, and facile integration with electrical circuits. However, mainstream silicon MEMS thermometry struggles with the trade-off between responsivity, temperature resolution, and sensitivity. In this work, we utilize the highest crystal quality single-crystal diamond and multi-mode resonance for MEMS cantilever thermometry to address these challenges. The resulting diamond MEMS thermometry exhibits unparalleled performance, with an ultra-high sensitivity of ≈22 nK^Hz-1/2, a high temperature resolution of 100 µK, and a wide-temperature range from 6.5 to 380 K. The groundbreaking sensing performance highlights the versatility and transformative potential of diamond MEMS resonator as the next-generation platform for ultrahigh-sensitivity and high-resolution temperature sensing in microscale or nanoscale space.