Additively manufactured MXene-based flexible triboelectric nanogenerator for energy harvesting

The development of scalable and flexible energy harvesting systems is crucial for powering next-generation wearable electronics. In this study, a 3D printed triboelectric nanogenerator (TENG) based on an MXene–silicone composite was fabricated using extrusion-based direct ink writing. Ti3C2Tx MXene nanosheets were synthesized via selective etching of Ti3AlC2 and incorporated into a silicone elastomer matrix at low concentrations (0–2 wt%) to improve dielectric and mechanical performance. The composite inks exhibited pronounced shear-thinning behavior, ensuring excellent printability and structural stability. Mechanical characterization showed enhanced tensile strength and Young’s modulus up to 1 wt% MXene while preserving the flexibility required for repeated contact–separation operation. The dielectric constant increased from 2.7 for pristine silicone to 5.5 at 1.5 wt% due to interfacial polarization, leading to improved surface charge generation. Optimization of the printed lattice thickness revealed that the 1 wt% MXene sample with a thickness of 0.8 mm produced the highest open-circuit voltage of approximately 58 V. The improved electrical output arises from the combined effects of dielectric enhancement, mechanical compliance, and micro-architected structural design. This work demonstrates a scalable micromanufacturing approach for developing tunable and high-performance flexible triboelectric energy harvesting devices.