Tunable mechanical coupling between driven microelectromechanical resonators

TL;DR

This paper demonstrates a microelectromechanical system where a silicon beam's resonance frequency is tunably coupled to a comb-drive actuator, enabling dynamic control of the coupling rate without significantly affecting the system's spring constant.

Contribution

It introduces a tunable coupling mechanism between microelectromechanical resonators using a comb-drive actuator and side-gate, with rapid switching capabilities.

Findings

Coupling rate is tunable by approximately 10% with the comb-drive and side-gate.

Effective spring constant remains nearly unchanged during tuning.

Coupling rate switching occurs at frequencies of at least 10 kHz.

Abstract

We present a microelectromechanical system, in which a silicon beam is attached to a comb-drive actuator, that is used to tune the tension in the silicon beam, and thus its resonance frequency. By measuring the resonance frequencies of the system, we show that the comb-drive actuator and the silicon beam behave as two strongly coupled resonators. Interestingly, the effective coupling rate (~ 1.5 MHz) is tunable with the comb-drive actuator (+10%) as well as with a side-gate (-10%) placed close to the silicon beam. In contrast, the effective spring constant of the system is insensitive to either of them and changes only by $\pm$ 0.5%. Finally, we show that the comb-drive actuator can be used to switch between different coupling rates with a frequency of at least 10 kHz.