Energy harvesting textiles represent a truly transformative development in the area of wearable smart textiles. These integrate renewable energy technologies—photovoltaic, piezoelectric, thermoelectric, and triboelectric systems—directly into fabrics to autonomously power low-power devices. Each harvesting principle brings unique advantages and limitations -- photovoltaic systems provide high energy output under light but face challenges in flexibility and washability; piezoelectric and triboelectric systems excel in capturing motion-induced energy but deliver low power densities; thermoelectric materials harness body heat, but the efficiency remains low. Recent advances in hybrid textile architectures demonstrate the feasibility of combining these principles within a single structure, using flexible materials like PVDF, PEDOT:PSS, CNTs, and MXenes. These hybrids show improved performance via energy complementation, especially when integrated using scalable techniques such as electrospinning, fiber coating, or embroidery.
Commercial viability of the systems remains somewhat poor by challenges in terms of scalability, energy density, mechanical durability, and washability. Compared to commercial batteries, current textile systems provide significantly lower energy outputs, suitable primarily for intermittent or low-demand applications such as biometric sensors or IoT wearables. Promising solutions include encapsulation techniques, electrospun nanofiber coatings, and the integration of energy storage units like supercapacitors. Several studies have demonstrated wash-resistant designs that maintain functionality across multiple laundry cycles, marking a critical step toward real-world adoption. While the field is still evolving, the convergence of material innovation, smart integration, and textile engineering is rapidly pushing energy harvesting textiles closer to practical reality.