Sustainable flexible wearable antenna using rubber substrate for wireless body area networks

The growing demand for flexible antennas in the telecommunications industry has driven the need for compact designs with improved performance. Microstrip antennas are particularly attractive due to their low profile, ease of fabrication, and adaptability. A key challenge in enhancing flexible antennas lies in selecting a suitable substrate. In this work, rubber is proposed as an alternative substrate material because of its flexibility, conductivity, efficiency, ease of fabrication, and water resistance, making it suitable for Wireless Body Area Network (WBAN) applications. The proposed antenna operates at 2.4 GHz with a relative permittivity (εr) of 3.0, a frequency commonly used for wearable devices. Two antenna designs, rectangular and circular microstrip patches, were developed, simulated, and analyzed using CST Microwave Studio (CST-MWS). Performance metrics including reflection coefficient, VSWR, gain, directivity, and bandwidth were evaluated under flat and bent conditions of 15°, 30°, 45°, and 90°. Results show that both designs achieved satisfactory performance, demonstrating their robustness and suitability for WBAN applications.