Aloe vera-PDMS blend thin films with combined triboelectric and polarization mechanisms for wearable energy harvesting

Abstract

The development of flexible and sustainable self-powered electronics has driven interest in high-performance triboelectric nanogenerators (TENGs). In this work, Aloe vera (Av) juice was directly incorporated into a polydimethylsiloxane (PDMS) matrix (5–40 wt%) to enhance the dielectric and polarization properties of the bulk material, representing a bio-derived blend system approach distinct from conventional layered Aloe vera–based devices. The polar and ionic constituents of Aloe vera improve dipolar and interfacial polarization, leading to enhanced charge storage and electrical output. The optimized 35 wt% Av–PDMS blend film exhibited a peak-to-peak open-circuit voltage of 61 V, an approximately nine-fold increase over pristine PDMS (6.8 V), along with a short-circuit current of 7.13 µA and a maximum power density of 55.8 mW m⁻² under quantized excitation. The device maintained stable performance over 10,000 tapping cycles and 5,000 bending and stretching cycles and successfully powered low-power electronic devices via a 4.7 µF capacitor. These results demonstrate that bio-derived dielectric engineering through direct Aloe vera incorporation is an effective strategy for improving the performance and durability of flexible TENGs for wearable and self-powered applications.