Phononic frequency combs with tunable frequency spacing for ultrasensitive temperature-sensing applications
Phys. Rev. Applied 25, 024022 – Published 6 February, 2026
DOI: https://doi.org/10.1103/nn4s-1yrc
Abstract
Phononic frequency combs, a series of equidistant spectral lines generated using micro-electromechanical and nano-electromechanical systems, have promising potential for improving the performance of sensing applications. In this work, we introduce and thoroughly analyze a temperature sensing approach using phononic frequency combs, where the temperature is tracked by the spacing between adjacent comb fingers in lieu of the traditional single resonance mode tracking. Here, we demonstrate phononic frequency comb generation using 1:2 internal resonance between two coupled circular membrane modes (0,1) and (2,1) on an aluminum scandium nitride resonator. We systematically study the tuning mechanisms of phononic frequency comb spacing subject to drive conditions and temperature perturbations within the entire detuning range. Our findings, backed up with an analytical model, show a controllable method to engineer the temperature sensitivity of comb spacing. The demonstrated tracking technique, coupled with narrowband electrical filtering, opens avenues for signal processing applications requiring highly controllable thermal sensitivity.
