Flexible and Wearable Patch Antenna Using Additive Manufacturing for Modern Wireless Applications

Abstract

In the past decade, a lot of research has been focused on wearable antennas for wireless applications. An abrupt increase in demand for wearable systems, providing wireless data transfer referring to body area network (BAN) and internet of thing (IoT), has led the industry towards the flexible and wearable antennas which provide comfort to the user along with the wireless applications such as health monitoring, location, entertainment, etc. This work represents a concept for 3D-printed flexible and wearable patch antenna printed using fused filament fabrication (FFF). The rheological, mechanical, and radio-frequency (RF) characteristics of the purposed antenna have been investigated. Thermoplastic polyurethane (TPU) granules with a melt flow index (MFI) of 29.75 g/10min have been used for the fabrication of substrate in this study. The TPU filament was extruded using a single screw extruder (SSE). Cotton + lycra woven fabric along with TPU (for acting as substrate) was selected due to cross-linking provided by cotton fibers. Mechanical testing of TPU and TPU + woven fabric suggested stiffness of 3.897 N/mm and 6.658 N/mm respectively. A ring resonator was used to test the RF characteristics of the printed patch antenna. The vector network analyzer (VNA) was used to check the RF characteristics of the ring resonator and suggested resonating frequency at 2.80 GHz with an insertion loss (S21) of 41.8843 dB.