Fabrication and evaluation of a flexible antenna device composed of a compatible iron-oxide clay in a PDMS graphene matrix

Abstract

Today, wearable devices are gaining more attention in life science fields due to their unique characteristics, like flexibility, durability, and the use of biodegradable materials along with low-cost fabrication. In this work, we create a flexible and robust conductive polymer composite based on iron oxide (ferromagnetic and dielectric material) and a thin film of clay doped with graphene nanoparticles using a sonochemical preparation method. This material may be applicable as a strip antenna in the future; thus, various characterization studies and measurements have been performed on the composite structure to test its applicability in a wearable device. Different spectroscopic techniques – thermogravimetric analysis (TGA) and surface-morphology analysis (transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis) – in addition to the use of electrochemical analysis techniques – electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) – are used to investigate the electrical properties of the antenna device; and particle-size analysis is used to determine the physical properties of the particle during fabrication. Moreover, infrared spectroscopy (IR) and UV-vis absorption analysis were used to confirm the fabrication process of the flexible chip, and its potential use as a wearable device for underground workers in the mining sector. We carried out measurements to evaluate the antenna performance, such as return loss characteristics in the WLAN band; the measurements and simulation outcomes show two frequency regions at 1.9 and 3.8 GHz.