Battery-Free Digitally Embroidered Smart Textile Energy Harvester for Wearable Healthcare IoTs

Smart textiles—fabrics integrated with electronics—have the potential to revolutionize e-healthcare applications by enabling sensing, communication, and interaction with the environment. This article focuses on developing a battery-free smart-textile-based energy harvester for powering Internet of Things (IoT)-enabled wearable sensors, with a particular emphasis on its application in e-healthcare. The energy harvester is digitally embroidered and can be easily integrated into textile products, including clothing. A multiport design was used, enabling it to harvest energy from multiple directions and convert it into electricity to power wearable sensors. A single element in the proposed multiport energy-harvesting array generates a beam with a peak gain of 7.25 dBi and approximately 68<inline-formula><tex-math notation="LaTeX">$^{\circ }$</tex-math></inline-formula> half-power beamwidth, using a simplified and compact design owing to the absence of complicated feeding networks. The performance of the energy harvester was evaluated through simulations and experiments. Furthermore, the feasibility of integrating the proposed energy harvester into commercially available IoT sensor nodes was demonstrated using a wirelessly powered wearable device. The device was shown to provide real-time temperature and humidity data without external batteries. The use of smart textiles and energy-harvesting technology offers a self-sustaining solution for wearable devices, greatly enhancing their functionality and usability, particularly for e-healthcare applications.