Phononic frequency combs in microelectromechanical systems

Phononic frequency combs are mechanical response features evidenced as a series of equispaced discrete spectral lines. These features have been experimentally observed in a multitude of microelectromechanical devices confirming theoretical predictions of such phenomena in FPUT chains. The formation of phononic frequency combs is mediated by nonlinear mode coupling and mixing, where comb-like spectra in the RF can be generated by driving a microelectromechanical device via a single-tone drive signal. The first systematic experimental observations were made in a system comprising two coupled modes in a single resonator device, and this has been followed by observations of the same phenomena in micromechanical systems comprising three coupled modes, and in coupled resonator devices, with comb features defined by the system and drive parameters. The engineering of phononic frequency combs has the potential to enable new applications such as stable resonance tracking in physical sensors, broadband vibration energy harvesting, and as component technologies for wireless communication systems and quantum information processing.