Multi-Indicator Ultrasensitive Temperature Sensing Platform Using Parametrically Excited Resonators

In this work, we demonstrate three different temperature sensing techniques that co-exist in a single nanomechanical drumhead resonator platform based on an aluminum scandium nitride (Al<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.</inf><inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</inf>Sc<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.2</inf>N) ultra-thin piezoelectric film. Each method demonstrates merits that can be leveraged for timing and/or sensing applications: (1) Tracking linear resonance gives rise to a temperature coefficient of frequency (TCF) as high as −1022 ppm/K at room temperature due to thermally induced stress. (2) The nondegenerate signal/idler tones produced through coupled nonlinear parametric interaction results in TCFs of opposite signs (-178 ppm/K and +89 ppm/K). Mixed parametric tones are trackable and open to TCF manipulation. (3) Tracking the spacing of phononic frequency comb (PFC) leads to an ultrahigh sensitivity with TCF exceeding +4300 ppm/K. These findings mark for the first time that the same mechanical platform is capable of producing not only giant TCFs but also engineered values, including TCF values of opposite signs.