Highly Sensitive Temperature Sensor Based on Coupled-Beam AlN-on-Si MEMS Resonators Operating in Out-of-Plane Flexural Vibration Modes

Abstract

This paper reports a type of highly sensitive temperature sensor utilizing AlN-on-Si resonators with coupled-beam structures of double- and triple-ended-tuning-fork (D/TETF). For both resonators, the out-of-plane flexural mode is adopted as it favors the effect of thermal mismatch between the composite layers inherent to the AlN-on-Si structure and thus helps attain a large temperature coefficient of resonant frequency (TCF). The analytical model to calculate TCF values of D/TETF AlN-on-Si resonators is provided, which agrees well with the finite-element simulation and experimental results. The resonant temperature sensor is built by closing the loop of the AlN-on-Si resonator, a transimpedance amplifier, a low-pass filter, and a phase shifter to form an oscillator, the output frequency of which shifts proportionally to the ambient temperature. The measured sensitivities of the temperature sensors using D/TETF resonators are better than -1000 ppm/°C in the temperature range of 25°C~60°C, showing great potential to fulfill the on-chip temperature compensation scheme for cofabricated sensors.

Reliability of MEMS inertial devices in mechanical and thermal environments: A review

“…Its operating temperature range was −40∼100 °C, and measurement range was −50∼50 g [ 81 ]. Cheng Tu et al proposed a high-sensitivity temperature sensor with a double-ended and triple-ended tuning fork (D/TETF) coupling beam structure, whose measurement sensitivity was better than −1000 ppm/°C in the temperature range of 25∼60 °C [ 82 ]. A stress isolation frame that is co-faced with a sensitive structural layer was proposed by Jing Zhang et al for thermal stress isolation of accelerometers.…”

Enhanced Sensing Mechanism Based on Shifting an Exceptional Point

“…For sufficiently small perturbation, the splitting is much larger than observed in conventional schemes where the response is proportional to the perturbation strength. The giant enhancement of EPs has been verified both theoretically and experimentally in various detection schemes [ 3 , 4 , 32 , 39 – 41 ] ranging from mass sensor [ 31 ] to nanoparticle detector [ 4 , 29 , 32 ], from magnetometer [ 34 , 39 ] to gyroscope [ 3 , 33 , 35 , 42 – 44 ]. Not only the presence of perturbation will cause the frequency splitting, but also the degeneracy of the linewidths disappears after introducing perturbation.…”

A Miniaturized Wireless Micropump Enabled by Confined Acoustic Streaming

“…In recent years, acoustic waves induced by the piezoelectric effect have been employed to drive liquids and manipulate particles in a wide range of miniaturized systems (especially microfluidic systems) [ 57 – 67 ]. These piezoelectric chips fabricated via advanced microelectromechanical system techniques [ 68 , 69 ] enable acoustofluidic micropumps (AFMPs) with great portability (simple and small structures, low power consumption, and low working voltage), high biocompatibility, a fast response time, and fair extensibility [ 23 , 50 – 54 ], which theoretically meets the requirements of a portable system as an ideal micropump. However, the existing AFMPs have unsatisfactory pumping performance due to their limited energy transduction efficiency (Table S2 ).…”