Nonlinear nano-electromechanical lattices for high-frequency, tunable stress propagation

TL;DR

This paper demonstrates active control of high-frequency mechanical wave propagation in nonlinear nanoelectromechanical lattices, enabling tunable phononic band gaps for advanced RF and biomedical applications.

Contribution

It introduces a nonlinear NEML platform with voltage-controlled band gap tuning and nonlinear effects, advancing dynamic control in nanoelectromechanical systems.

Findings

Voltage-dependent band gap shifts by applying DC voltage.

Nonlinear effects induce phononic band gaps in the acoustic branch.

Device operates in the 10-30 MHz RF range.

Abstract

Active manipulation of mechanical waves at high frequencies opens opportunities in heat management, radio-frequency (RF) signal processing, and quantum technologies. Nanoelectromechanical systems (NEMS) are appropriate platforms for developing these technologies, offering energy transducibility between different physical domains, for example, converting optical or electrical signals into mechanical vibrations and viceversa. Existing NEMS platforms, however, are mostly linear, passive, and not dynamically controllable. Here, we report the realization of active manipulation of frequency band dispersion in one-dimensional (1D) nonlinear nanoelectromechanical lattices (NEML) in the RF domain (10-30 MHz). Our NEML is comprised of a periodic arrangement of mechanically coupled free-standing nano-membranes, with circular clamped boundaries. This design forms a flexural phononic crystals with a well-defined band gaps, 1.8 MHz wide. The application a DC gate voltage creates voltage-dependent on-site potentials, which can significantly shift the frequency bands of the device. Dynamic modulation of the voltage triggers nonlinear effects, which induce the formation of phononic band gaps in the acoustic branch. These devices could be used in tunable filters, ultrasonic delay lines and transducers for implantable medical devices.