4,218 publications from this institution
The first integration of multiple energy harvesters and a storage device along single fiber using ZnO nanowires (NWs) and graphenes as the basic materials is reported. This energy generation and storage device allows simultaneous harvesting of solar and mechanical energy. The unique architecture of fiber-based electrodes and use of ZnO NWs, and graphenes as active material and electrodes could be useful for the future development of flexible and wearable electronics.
Wedemonstrateacylindrical rotatingtriboelectricnanogenerator(TENG)basedonsliding electrification for harvesting mechanical energy from rotational motion. The rotating TENG is based on a coreshell structure that is made of distinctly different triboelectric materials with alternative strip structuresonthesurface.Thechargetransferisstrengthenedwiththeformationofpolymernanoparticles onsurfaces. During coaxial rotation,a contact-induced electrification andthe relative slidingbetween the contactsurfacesofthe coreand theshellresultinanin-planelateral polarization, whichdrivesthe flow of electrons in the external load. A power density of 36.9 W/m 2 (short-circuit current of 90 μA and open- circuit voltage of 410 V) has been achieved by a rotating TENG with 8 strip units at a linear rotational velocity of 1.33 m/s (a rotation rate of 1000 r/min). The output can be further enhanced by integrating morestripunitsand/orapplyinglargerlinearrotationalvelocity.Thisrotating TENGcanbeusedasadirectpowersourcetodrivesmallelectronics,suchas LED bulbs. This study proves the possibility to harvest mechanical energy by TENGs from rotational motion, demonstrating its potential for harvesting the flow energy of air or water for applications such as self-powered environmental sensors and wildlife tracking devices.
Abstract Powering electronics in agricultural irrigation systems relies highly on conventional batteries, which often suffers from the issues of bulkiness, low reliance, wiring complexity and poor environmental adaptability. In such settings, as a new form of sustainable power sources, the hybrid electromagnetic-triboelectric nanogenerators (EM-TENGs) have the potential to become a superior alternative compared with conventional batteries. Here, to address the need to durably harvest and utilize rotational mechanical energy of water pumps in agricultural irrigation systems, we design and develop a compact hybrid EM-TENG with a coaxial configuration of dual integrated rotors. Device performance is separately characterized and optimized for the components of the electromagnetic generator (EMG) and the triboelectric nanogenerator (TENG), with the maximum output powers of 95.10 mW and 2.94 mW achieved under the rotation speed of 700 rpm, respectively. Meanwhile, rotation speeds can be accurately sensed by the TENG module through the parameter of characteristic frequency with errors below 2%. Moreover, our EM-TENG is able to charge a 100 μ F capacitor to 5 V in 25 s under the rotation speed of 600 rpm and power some indispensable electronic devices in agricultural environments such as timers and thermohygrometers. Our EM-TENG offers a new solution to supply power to small electronics in a compact and sustainable manner in the context of agricultural irrigation systems, circumventing the inherent disadvantages of traditional batteries and power grids in such systems.
Twists and turns: ZnS nanohelices have been synthesized in high yield by using a simple vapor deposition process. These nanohelices also have Y-shaped branched secondary growths, which always point toward the inside of the helix. The formation of these hierarchical structures is discussed based on structural information.
