1 research outputs found
Morphological Characterization and Lumped Element Model of Graphene and Biochar Thick Films
Carbon based materials exhibit interesting mechanical, thermal and electrical properties
which make them excellent contenders for use as fillers in composites as film. Graphene has been
vastly used among the carbon-based materials. More recently eco-friendly carbon-based materials
like biochar have emerged. The deployment of carbon-based materials in films needs to be studied
since films are more versatile and permit the exploitation of electrical properties of such materials
over circuits and systems. Typical circuits and systems exploiting electrical properties of novel
materials perform a number of applications including sensing, detection, tunable devices and energy
harvesting. In this paper, films composed of 9:1 graphene or biochar are deployed on a microstrip
line. The morphological properties of graphene and biochar and their respective films are studied
with Raman spectra and Field Emission Scanning Electron Microscope (FESEM). The electrical
properties (four-point probe measurements and scattering parameter measurements) of the films.
Low frequency measurements are used as starting point for circuit models estimating the lumped
impedance of the films. From the morphological characterization it is shown that biochar films
appear as granulates carbonaceous materials whereas graphene films contains several flakes forming
a network. From the low frequency measurements and microwave characterization it is seen that
graphene films are more conductive as compared to biochar films. In many applications, it is useful
to know the surface impedance of the film since it varies on interaction with any external stimulus
(variation of pressure, humidity, gas, etc.)