A Self-Sustained Mass Sensor With Physical Closed Loop Based on Thermal-Piezoresistive Coupled Resonators

Abstract

This article reports a mode-localized mass 1 sensor based on thermal-actuation piezoresistive-detection 2 self-oscillated weakly coupled resonators. Detailed theo-3 retical models and simulations of the self-oscillation of 4 the coupled resonators were established and were also 5 verified using optical and electrical measurements. The sen-6 sor was fabricated and characterized in terms of stability, 7 linearity, sensitivity, and resolution. Supplied with only a 8 constant direct current (DC), the resonant mass sensor 9 could oscillate at its resonant frequency with an ultrahigh 10 quality factor of 95 k in air. By implementing the principle of 11 the mode localization phenomenon, ∼200 times parametric 12 sensitivity improvement with amplitude ratio output was 13 implemented compared to the traditional frequency output 14 metric. A real-time mass detector with 84-fg resolution 15 and larger than ∼700-pg linear measurement range was 16 obtained.

Silicon Carbide-on-Insulator Thermal-Piezoresistive Resonator for Harsh Environment Application

“…Since the first miniature Si piezoresistive heat engine was reported in 2011 [1], a variety of self-sustained thermal-piezoresistive resonators or oscillators have been developed for mass sensing [2,3], Lorentz force measurement [4], gas detection [5], and signal amplification [6]. It was demonstrated that the thermalpiezoresistive effect is strong enough to initiate and maintain the mechanical oscillation of the resonator driven by direct current (DC), without the demand for any external alternating current (AC) source and amplifying circuitry.…”