Advancing sustainable RF energy harvesting for wearable electronics with 2.45 GHz textile-printed rectennas.

The growth of IoT and wearable electronics demands sustainable energy solutions beyond short-lived, waste-generating batteries. RF energy harvesting offers a self-powered alternative by capturing ambient RF energy. However, implementing this technology on textile substrates remains challenging due to material incompatibility, ink toxicity, substrate porosity, and scalability constraints. This study addresses these challenges by developing optimized fabrication techniques for printed textile rectennas operating at 2.45 GHz. It focuses on conductive ink formulations tailored for textiles, scalable integration methods such as screen-printing and doctor blade techniques, and improved attachment methods for lumped components, ensuring full integration of a microstrip patch antenna and rectifier circuit onto fabric. The research systematically examines the impact of substrate porosity, ink adhesion, material losses, mechanical deformation, dielectric variability, and surface roughness on energy harvesting efficiency. Additionally, it promotes environmentally sustainable solutions by reducing reliance on volatile organic compounds (VOCs) and complex fabrication processes. Electromagnetic simulations and experimental validations confirm the rectenna's capability to harvest 2.4 GHz ISM band energy, despite challenges such as dielectric sensitivity and conductive ink losses. This work establishes a scalable, cost-effective framework for next-generation wearable and IoT applications, advancing flexible electronics and self-sustaining smart textiles.