Trimodal Hybrid Nanogenerators Comprising Thermoelectric, Triboelectric, and Piezoelectric Effects in Stretchable, All-in-One Energy Harvesting Modules

Hybrid nanogenerators are ubiquitous in today’s energy-intensive society and operate as self-powered systems that have wide-ranging applications in environmental monitoring, medical, and Internet-of-things-based devices. Triboelectric and piezoelectric devices operate on the principle of mechanical-to-electrical energy conversion, while thermoelectric devices are defined by their ability to convert thermal energy into scalable electrical outputs. In this work, we report a multimodal all-in-one nanogenerator based on a BaTiO 3 (BTO)-decorated single-walled carbon nanotube (BTO@SWCNT) elastomer composite system, which harvests energy via triboelectric, piezoelectric, and thermoelectric effects. A liquid polyisoprene rubber matrix was employed as a matrix for the filler systems and subsequently modified using stencil printing to create a flexible device. The internal coupling of piezoelectric and triboelectric modes in a single composite layer yields significantly enhanced open-circuit voltages of 119 V (at 5 Hz), nearly twice the magnitude of that containing pristine SWCNT (65 V). The improvement is attributed to piezoelectric charge generation from the embedded BTO nanoparticles and enhanced interfacial polarization, which together boost charge density while avoiding excessive conductivity. The composite also exhibited an increased Seebeck coefficient of ∼77 μV K –1 and a power factor of 7.8 × 10 –3 W m –1 K –2, as compared to that containing pristine SWCNTs (62 μV K –1 and 0.28 W m –1 K –2 ). Morphological studies reveal successful nanoscale integration of BTO on SWCNT surfaces, forming percolating networks at ultralow filler loadings (∼0.05 wt %). Mechanical tests confirm that the hybrid filler reinforces the rubber matrix without sacrificing flexibility. Our work highlights a promising materials strategy for self-powered systems by integrating high-dielectric piezoceramics with conductive nanostructures in a soft polymer, paving the way for versatile wearable energy harvesters.