Printed Triboelectric Nanogenerator Incorporating MXene-Enhanced PVBVA for Skin-Interactive Devices and Touch-Sensing Arrays

The adoption of soft contact structure designs in triboelectric nanogenerators (TENGs) has been a favored approach to enhance their durability. However, this method often presents a significant challenge to achieving high output performance. TENGs are often limited by their reliance on specific tribo-materials, which can restrict their practicality and performance. To address these limitations, we use additive electronics manufacturing methods for TENG fabrication, which enables energy generation from various tribomaterials, including human skin [1-3]. Our innovation lies in the integration of a high-performance polymer, Poly (<i>vinyl butyral-co-vinyl alcohol-co-vinyl acetate</i>) (PVBVA), with Ti₃C₂ MXenes [4], two dimensional transition metal carbides etched from the Ti₃AlC₂ MAX phase ceramics. Inks from these materials are formulated for microdispense printing and printed onto aluminum substrates using a Hyrel extrusion printer. This combination significantly enhances the triboelectric properties of the manufactured TENG device.<br/>Our findings show that the PVBVA layer alone yields a triboelectric output of approximately 110 V. However, with the introduction of MXene at a concentration of 2.75 mg/ml, the output escalates to 150 V, and further increases to 250 V at a concentration of 5.5 mg/ml, demonstrating a substantial enhancement in performance. Beyond energy harvesting, we leveraged this TENG technology in a water energy harvesting system, effectively extracting energy from sources such as raindrops. Additionally, we developed a 2 x 2 touch sensor array utilizing this technology. This sensor array can generate charge through the triboelectric effect and dynamically map the output voltage values in response to touch, showcasing its potential for human-machine interaction and touch-sensitive interfaces.<br/>In summary, our research introduces a groundbreaking approach to TENG fabrication by combining 3D printing technology with a PVBVA-MXene composite. This leads to TENGs with markedly improved triboelectric performance. The versatility of these TENGs not only enables efficient energy harvesting from environmental sources like rain but also holds significant promise for applications in touch-sensitive devices. This makes them a valuable asset for developing self-powered devices and interactive interfaces in fields such as healthcare and robotics.<br/>References: <b>[1]</b> Sun, Y.; Li, Y.Z.; Yuan, M. Requirements, challenges, and novel ideas for wearables on power supply and energy harvesting. <i>Nano Energy</i> <b>2023</b>, <i>115</i>, 108715. <b>[2]</b> Wang, W.; Xu, L.; Zhang, L.; Zhang, A.; Zhang, J. Self-Powered Integrated Sensing System with In-Plane Micro-Supercapacitors for Wearable Electronics. <i>Small</i> <b>2023</b>, 2207723. <b>[3] </b>An, B.W.; Shin, J.H.; Kim, S.Y.; Kim, J.; Ji, S., Park; J., Lee; Y., Jang; J., Park, Y.G.; Cho, E.; Jo, S. Smart sensor systems for wearable electronic devices. <i>Polymers</i> <b>2017</b>, <i>9(8)</i>, 303. <b>[4]</b> Naguib, M.; Kurtoglu, M.; Presser, V.; Lu, J.; Niu, J.; Heon, M.; Hultman, L.; Gogotsi, Y.; Barsoum, M.W.; Two dimensional nanocrystals produced by exfoliation of Ti3AlC2. <i>Adv. Mater.</i> <b>2011</b>, <i>23(37)</i>, 4248–4253.