Dielectric characterization of Flexible Pineapple Leaf Fiber (PALF) Reinforced Polydimethylsiloxane (PDMS) composite as a potential antenna substrate for wearable antenna application

The rapid advancement of wearable technology has increased the demand for flexible, lightweight, and high-performance antenna substrates. This study investigates the dielectric properties of Pineapple Leaf Fiber (PALF) reinforced Polydimethylsiloxane (PDMS) composites as a potential substrate for wearable antennas. The fabrication method used was Manual Polymer Mixing Method. The composites, with fiber loadings from 10wt.% to 90wt.%, underwent alkaline treatment using Sodium Hydroxide (NaOH) to enhance fiber-matrix compatibility. Dielectric properties were analyzed using a Vector Network Analyzer (VNA) to measure dielectric constant, loss tangent, and permittivity. Results indicate that increasing fiber loading improves the dielectric constant, while alkaline treatment reduces the loss tangent, enhancing performance. The treated composites demonstrated superior mechanical stability and flexibility, crucial for wearable applications. Additionally, CST Studio-designed antenna prototypes showed improved radiation patterns, return loss, and efficiency, confirming PALF-PDMS as a suitable dielectric substrate. These findings highlight the potential of sustainable natural fibers for advanced, eco-friendly electronic applications.