Development and Characterization of Freestanding Poly (Methyl Methacrylate)/Monolayer Graphene Membrane

Badariah Bais,Norhayati Soin,Burhanuddin Yeop Majlis,Norliana Yusof,Jumril Yunas

doi:10.1109/access.2020.2972558

Badariah Bais, Norhayati Soin + Show 3 more

Open Access

https://doi.org/10.1109/access.2020.2972558

Copy DOI

Abstract

Graphene-polymer based materials are gaining more popularity among researchers due to its mechanical properties that are found to be suitable to be used in various micro/nanoscale application requiring highly sensitive sensors. This research ventured into the fabrication and characterization process of a freestanding poly (methyl methacrylate) (PMMA) on monolayer graphene (Gr) yielding a (PMMA/Gr) membrane. In the process of transferring the chemical vapor deposition (CVD) graphene film over a cavity that was developed on a silicon substrate, the wet transfer method was used. Five repetitions of the nanoindentation testing had been carried out on the flexible membrane which resulted in a reproducible deflection, when exerted with a maximum loading of 10 mN. The indented (PMMA/Gr) membrane showed an identical elastic behavior with Young's modulus of 0.18 GPa. The highest deflection of approximately 22 μm at 1.6 mN maximum loads and the tensile stress of 0.58 MPa was obtained from the indentation testing analysis. The combination of PMMA-Graphene materials as a membrane has shown impressive changes to its mechanical properties. Besides maintaining its viscoelastic-plastic behavior which contributed to its flexibility, the presence of a graphene layer provided strong support to prevent damages to the membrane. Meanwhile, PMMA properties with low elastic modulus have contributed to the increased of the mechanical sensitivity of the membrane. Based on this research, the mechanical sensitivity of (PMMA/Gr) is reported to be 0.15 nm/Pa, which is much higher compared to a typical conventional membrane. It was proven that the hybrid (PMMA/Gr) membrane was extremely sensitive to the subjected pressures, thus, shown its potential to be applied as a micro-electro-mechanical systems (MEMS) capacitive pressure sensor.

Highlights

Graphene membrane has garnered significant popularity due to its extraordinary mechanical, electrical and thermal properties, as well as the ability to produce graphene-based devices
These results showed that the (PMMA/Gr) film was successfully transferred over to the silicon etched cavity forming a freestanding (PMMA/Gr) membrane
From the results of FESEM and Raman, it was shown that the (PMMA/Gr) film had been successfully transferred onto an etched silicon substrate yielding a fully suspended (PMMA/Gr) membrane

Summary

Introduction

Graphene membrane has garnered significant popularity due to its extraordinary mechanical, electrical and thermal properties, as well as the ability to produce graphene-based devices. One of the interesting mechanical behaviors of a graphene membrane is that it can be constructed using the. Transfer method which only utilized the van der Waals (vdW) adhesion between the underlying substrate and the graphene layer to fix the membrane in place. Due to the material properties of the layered graphene-polymer that may not be similar to the material of the bulk polymer [1], [2], it has piqued the interest of many researchers to investigate further on the characterization of the freestanding layered graphenepolymers. Extensive research on the behavior of the freestanding (PMMA/Gr) membranes is crucial in order to.

Objectives

Methods

Results

Conclusion