Characterization and evaluation of a screen-printed stretchable silver-PDMS microstrip antenna for wearable electronics

Abstract

The rapid development of wearable electronics and wireless body area networks (WBANs) demands antennas that integrate robust electrical performance, mechanical stretchability, and biosafety for dynamic human-centric applications. While liquid metals and geometric designs have advanced stretchable antennas, challenges such as fabrication complexity, oxidation risks, and high costs hinder their scalability. This work presents a screen-printed polydimethylsiloxane (PDMS)-based stretchable microstrip antenna fabricated using a commercial silver-based conductive paste. By systematically analyzing the thermal stability, rheological behavior, and sintering properties of the silver paste, we optimized screen-printing and thermal sintering parameters (temperature: 140 °C, duration: 30 min) to achieve a dense conductive layer of the antenna with robust substrate adhesion and strain-resistant electrical properties. The fabricated antenna operates across the 2.1–2.9 GHz band, covering the desirable industrial, scientific, and medical (ISM) frequencies, with stable impedance matching (S11 <  − 10 dB) and omnidirectional radiation. Importantly, the antenna retains 99 % of its initial conductivity after 100 stretching cycles at 15 % strain and exhibits less than 15 % frequency shift under repeated deformation. Additionally, the antenna’s specific absorption rate (SAR) under near-body conditions remains below 1.6 W/kg (1 g average) or 2.0 W/kg (10 g average), compliant with international safety standards. By synergizing material optimization with scalable screen-printing processes, this study offers a cost-effective, mechanically robust, and biosafe solution for next-generation wearable communication systems.