On-Demand Wearable Piezoelectric Textiles Enabled by Lead-Free Perovskite and Conducting Polymer

In recent years, the demand for smart textiles has been increasing day by day in healthcare devices and wearable sensor applications. In this regard, we introduce a novel approach to create a three-layer wearable textile piezoelectric nanogenerator (t-PENG) using a continuous electrospinning process. The central layer is the active component, composed of Cs₃Bi₂I₉-PVDF (PVDF-CBI) nanofiber, while the outer layers consist of conducting electrode nanofiber mats (PVDF-PEDOT) with a high electrical conductivity of ~2.2 S m^-1. By incorporating perovskite Cs₃Bi₂I₉ nanofillers, we have successfully induced a 100% yield of the electroactive β-phase within the PVDF matrix. Our PENG exhibits outstanding performance metrics, including a remarkable open circuit voltage of ~12 V, a short circuit current of 7 µA, and a power density of 3 µW cm^-2. Furthermore, it boasts exceptional breathability (~1.13 kg m^-2 day^-1), flexibility, water-resistant properties (as indicated by a water contact angle of ~138⁰), and impressive mechanoacoustic sensitivity (with a sensitivity value of Sm ~5 V Pa^-1). These functionalities make t-PENG suitable for use in robust wearable devices, enabling efficient monitoring of human physiological motions and simultaneous harvesting of biomechanical energy.