Spray Coated GNP-PDMS Flexible Patch Antenna-Sensor for Wireless Wearable Applications

This paper presents the synthesis and performance of a novel flexible patch antenna sensor based on graphene nanoplatelets (GNP) material designed to operate at the 5.8 GHz frequency, targeting wearable applications. The fabrication process employed in this chapter involved a simple yet effective spray coating method, utilizing a GNP dispersion applied with a spray gun to form a rectangular patch with a full ground plane on the PDMS substrate. This method offers the advantages of being cost-effective and scalable, making it suitable for large-scale production. The antenna's performance as a sensor was evaluated by subjecting it to different bending scenarios, mimicking both compressive (positive bending) and tensile (negative bending) strains. The resulting shifts in resonant frequency under these conditions offered important information about the sensor's sensitivity. The practical applicability of the antenna sensor was demonstrated through human limb motion detection experiments, specifically tracking wrist movements. The sensor's ability to detect upward and downward wrist motions through variations in the normalized frequency output highlights its potential for real-world wearable applications. In addition to its promising performance, the operation of this antenna within the Industrial/Scientific/Medical (ISM) band at 5.8 GHz opens up a range of potential applications.