Harvesting vibration energy to power wearable devices has become a hot research topic, while the output power and conversion efficiency of a vibration energy harvester with a single electromechanical conversion mechanism is low and the working frequency band and load range are narrow. In this paper, a new structure of piezoelectric electromagnetic coupling up-conversion multi-directional vibration energy harvester is proposed. Four piezoelectric electromagnetic coupling cantilever beams are installed on the axis of the base along the circumferential direction. Piezoelectric plates are set on the surface of each cantilever beam to harvest energy. The permanent magnet on the beam is placed on the free end of the cantilever beam as a mass block. Four coils for collecting energy are arranged on the base under the permanent magnets on the cantilever beams. A bearing is installed on the central shaft of the base and a rotating mass block is arranged on the outer ring of the bearing. Four permanent magnets are arranged on the rotating mass block and their positions correspond to the permanent magnets on the cantilever beams. The piezoelectric cantilever is induced to vibrate at its natural frequency by the interaction between the magnet on cantilever and the magnets on the rotating mass block. It can collect the nonlinear impact vibration energy of low-frequency motion to meet the energy harvesting of human motion.
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http://dx.doi.org/10.3390/mi11010080 | DOI Listing |
Phys Chem Chem Phys
January 2025
Department of Chemistry, COMSATS University Islamabad, Abbottabad Campus, Abbottabad-22060, Pakistan.
The design and synthesis of nonlinear optical (NLO) materials are rapidly growing fields in optoelectronics. Considering the high demand for newly designed materials with superior optoelectronic characteristics, we investigated the doping process of Group-IIIA elements (namely, B, Al and Ga) onto alkali metal (AM = Li, Na and K)-supported COLi (AM@COLi) complexes to enhance their NLO response. The AM-COLi complexes retained their structural features following interaction with the Group-IIIA elements.
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January 2025
Chemistry Department, Southern Methodist University, Dallas, Texas, USA.
Using the QM/MM methodology and a local mode analysis, we investigated a character and a strength of FeS bonds of heme groups in oxidized and reduced forms of Bacterioferritin from Azotobacter vinelandii. The strength of the FeS bonds was correlated with a bond length, an energy density at a bond critical point, and a charge difference of the F and S atoms. Changing the oxidation state from ferrous to ferric generally makes the FeS bonds weaker, longer, more covalent, and more polar.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Division of Energy, Matter and Systems, School of Science and Engineering, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA.
Developing efficient path integral (PI) methods for atomistic simulations of vibrational spectra in heterogeneous condensed phases and interfaces has long been a challenging task. Here, we present the h-CMD method, short for hybrid centroid molecular dynamics, which combines the recently introduced fast quasi-CMD (f-QCMD) method with fast CMD (f-CMD). In this scheme, molecules that are believed to suffer more seriously from the curvature problem of CMD, e.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Center for Nanoscience and Sustainable Technologies (CNATS), Universidad Pablo de Olavide, 41013 Seville, Spain.
The proton bond is a pivotal chemical motif in many areas of science and technology. Its quantum chemical description is remarkably challenged by nuclear and charge delocalization effects and the fluxional perturbation that it induces on molecular substrates. This work seeks insights into proton bonding at sub-kelvin temperatures.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, China.
Fluorescence thermometry based on metal halide perovskites is increasingly becoming a hotspot due to its advantages of high detection sensitivity, noninvasiveness, and fast response time. However, it still presents certain technical challenges in practical applications, such as complex synthesis methods, the use of toxic solvents, and being currently mainly based on the visible/first near-infrared light with poor penetration and severe autofluorescence. In this study, we synthesize the second near-infrared (NIR-II) luminescent crystals based on Yb/Nd-doped zero-dimensional CsScCl·HO by a simple "dissolve-dry" method.
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