Actuation of graphene membranes through surface acoustic waves

Graphene has emerged as a promising material to develop new types of sensors thanks to its unique properties. When used to implement suspended membranes or ribbons, the resultant structure is extremely light and hence very easy to perturb by external stimuli, which translates into outstanding sensitivities.

One of the major challenges is the need for actuation mechanisms to set suspended graphene membranes into vibration. Electrostatic actuation is commonly found in previous studies. However, this mechanism imposes important limitations on the size of the membranes and the membrane-electrode gap. In this project, a new approach will be explored consisting in suspending the graphene membrane on top of a piezoelectric film. Interdigitated electrodes (IDT) on the film will generate surface acoustic waves (SAW) on the substrate that will propagate to the suspended graphene film. The goal is to demonstrate this new actuation concept for graphene and to study the mechanical coupling of acoustic waves from the substrate to graphene for different fabrication methods.

This project is a collaboration between Tomás Manzaneque García and Sten Vollebregt

Assignment

• Perform a literature review on the existing actuation methods for suspended graphene and the generation of SAW on piezoelectric substrates.
• Design and simulate SAW devices based on aluminium nitride. Simulate the excitation of membrane vibrations through SAW.
• Fabricate SAW devices with graphene membranes integrated, optimizing fabrication methods already available at EKL.
• Characterize the resulting devices with electrical and optical measurements.

Requirements

You must be motivated to learn and apply different techniques for fabricating new devices. Notions of mechanical resonators or acoustic devices is desirable. Experience with FEM simulation packages such as Comsol is a plus.

Contact

Last modified: 2022-02-16