Morphological and Radio Frequency Characterization of Graphene Composite Films

Abstract

Graphene is a monolayer of carbon atoms which exhibits remarkable electronic and mechanical properties. Graphene based nano-materials have gained a lot of interest for many applications. In this paper, inks with three different graphene concentrations (12.5, 25, and 33 wt % in graphene) were prepared and deposited by screen printing. A detailed investigation of films' surface morphology using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM) revealed that the graphene films present a homogeneous dispersion of the filler with a comparatively lower surface roughness at higher concentrations and negligible agglomerates. The films were then printed between copper electrodes on FR-4 substrate (trade name for glass-reinforced epoxy laminate material), commonly used in Radio Frequency (RF) circuits, and the measured scattering parameters analyzed. Finally, the reflection coefficient of a patch antenna, fabricated on FR-4 substrate with and without a stub loaded by a thin film were measured. The difference of the resonant frequency due to the different interaction between graphene flakes and polymer binders shows attractive features of functionalized graphene films for chemical and bio-sensing applications.

Graphene and MWCNT Printed Films: Preparation and RF Electrical Properties Study

“…Their possible applications span from gas sensors and RFID [11,12] to actuators and conductive electrodes [13,14] and microwave sensors [15]. Screen printing constitutes the most employed additive manufacturing technique for the deposition of thick films [16].…”

Influence of Various Technologies on the Quality of Ultra-Wideband Antenna on a Polymeric Substrate

“…The future of graphene-based materials is bright due to their beneficial properties and, most importantly, their ecological origin. Graphene is an organic material, and its use in combination with polymeric insulators enables green electronics [ 59 , 60 ]. Graphene has a lower conductivity than printed metallic inks or pastes based on silver particles, which is the most frequently used conductor material in the fabrication of flexible antennas [ 11 ].…”

“…The process of the sintering of particles lies in a connection of particles by necks into the conductive structure, whereas the final structure consists of the conductive necks and polymeric material of which the cavities around the necks are filled [ 67 ]. This polymeric material and its particle dispersion have a direct effect on how the transmitted signal scatters [ 59 ]. The behavior of the electronics structure (antenna, filter, etc.)…”

Correlation of Transmission Properties with Glucose Concentration in a Graphene-Based Microwave Resonator

“…Printed graphene film [10,[12][13][14] can be used for many applications as flexible electronics [15], humidity sensors [16,17], electro-chemical sensors [18][19][20][21][22][23][24][25], bio-molecular and drugs detection, and monitoring [18].…”