A Triboelectric Nanogenerator Based on Sodium Chloride Powder for Self-Powered Humidity Sensor

Harnessing Green Electricity from Food: A Split Black Gram-Based Triboelectric Nanogenerator for a Self-Powered Autonomous Lighting System and Portable Electronics

Triboelectric nanogenerators (TENGs) represent a promising solution to mounting environmental concerns associated with battery disposal amid the escalating demand for portable electronics. However, prevailing TENG fabrication predominantly relies on nonbiodegradable, nonbiocompatible, and synthetic materials, posing a grave ecological threat. To mitigate this, there is a pressing need to develop eco-friendly and green TENGs leveraging sustainable, naturally occurring materials. This study pioneers the use of split black gram (SBG) as a tribo-positive material for TENGs. SBG's effectiveness as a tribo-positive material stems from its abundance of oxygen-containing functional groups, as confirmed by FTIR analysis, facilitating electron donation during the triboelectric process. SBG offers compelling advantages, including widespread availability, cost-effectiveness, biodegradability, and hydrophobic and adhesive properties due to its richness in starch and protein, positioning it as an optimal choice for eco-conscious TENG manufacturing. The fabrication process of an SBG-TENG is not only economical and facile but also solvent-free, requiring no specialized tools. Demonstrating commendable performance, the SBG-TENG achieves a maximum power density of 15.36 μW/cm2 at 1 MΩ, with an open circuit voltage of 84 V and short circuit current of 28 μA, comparable to recent studies. In practical applications, the SBG-TENG seamlessly integrates with LEDs and portable electronic devices via a full bridge rectifier, successfully powering them postcapacitor charging. Moreover, an autonomous lighting system is developed by embedding the SBG-TENG in a foot mat, enabling wireless light control through human stepping on the mat, introducing power-saving functionality for residential and office environments. In essence, the introduction of the SBG-TENG not only delivers cost-effectiveness but also minimizes the environmental impact by harnessing sustainable energy from food sources.

Triboelectric behaviour of selected zeolitic-imidazolate frameworks: exploring chemical, morphological and topological influences

Tribo- and contact electrification remain poorly understood, baffling and discombobulating scientists for millennia. Despite the technology needed to harvest mechanical energy with triboelectric generators being incredibly rudimentary and the fact that a triboelectric output can be obtained from almost any two material combinations, research into triboelectric generator materials typically focuses on achieving the highest possible output; meanwhile, understanding trends and triboelectric behaviours of related but lower performing materials is often overlooked or not studied. Metal-organic frameworks, a class of typically highly porous and crystalline coordination polymers are excellent media to study to fill this knowledge gap. Their chemistry, topology and morphology can be individually varied while keeping other material properties constant. Here we study 5 closely related zeolitic-imidazolate type metal-organic frameworks for their triboelectric performance and behaviour by contact-separating each one with five counter materials. We elucidate the triboelectric electron transfer behaviour of each material, develop a triboelectric series and characterise the surface potential by Kelvin-probe force microscopy. From our results we draw conclusions on how the chemistry, morphology and topology affect the triboelectric output by testing and characterising our series of frameworks to help better understand triboelectric phenomena.

Editorial for Special Issue: Advanced Materials and Technologies in Nanogenerators

Nanogenerators, based on Maxwell's displacement current as the driving force, have inspired a new and developing field since their invention in 2006 [...].

A Flexible TENG Based on Micro-Structure Film for Speed Skating Techniques Monitoring and Biomechanical Energy Harvesting

Wearable motion-monitoring systems have been widely used in recent years. However, the battery energy storage problem of traditional wearable devices limits the development of human sports training applications. In this paper, a self-powered and portable micro-structure triboelectric nanogenerator (MS-TENG) has been made. It consists of micro-structure polydimethylsiloxane (PDMS) film, fluorinated ethylene propylene (FEP) film, and lithium chloride polyacrylamide (LiCl-PAAM) hydrogel. Through the micro-structure, the voltage of the MS-TENG can be improved by 7 times. The MS-TENG provides outstanding sensing properties: maximum output voltage of 74 V, angular sensitivity of 1.016 V/degree, high signal-to-noise ratio, and excellent long-term service stability. We used it to monitor the running skills of speed skaters. It can also store the biomechanical energy which is generated in the process of speed skating through capacitors. It demonstrates capability of sensor to power electronic calculator and electronic watch. In addition, as a flexible electrode hydrogel, it can readily stretch over 1300%, which can help improve the service life and work stability of MS-TENG. Therefore, MS-TENG has great application potential in human sports training monitoring and big data analysis.

α-Fe2O3 Nanoparticles Aided-Dual Conversion for Self-Powered Bio-Based Photodetector

Eco-friendly energy harvesting from the surrounding environment has been triggered extensive researching enthusiasm due to the threat of global energy crisis and environmental pollutions. By the conversion of mechanical energy that is omnipresent in our environment into electrical energy, triboelectric nanogenerator (TENG) can potentially power up small electronic devices, serves as a self-powered detectors and predominantly, it can minimize the energy crisis by credibly saving the traditional non-renewable energy. In this study, we present a novel bio-based TENG comprising PDMS/α-Fe2O3 nanocomposite film and a processed human hair-based film, that harvests the vibrating energy and solar energy simultaneously by the integration of triboelectric technology and photoelectric conversion techniques. Upon illumination, the output voltage and current signals rapidly increased by 1.4 times approximately, compared to the dark state. Experimental results reveal that the photo-induced enhancement appears due to the effective charge separation depending on the photosensitivity of the hematite nanoparticles (α-Fe2O3 nanoparticles) over the near ultraviolet (UV), visible and near infrared (IR) regions. Our work provides a new approach towards the self-powered photo-detection, while developing a propitious green energy resource for the circular bio-economy.