Phys.org July 8, 2024 GHz burst-mode femtosecond (fs) laser provides distinct characteristics in materials processing as compared with the conventional irradiation scheme of fs laser (single-pulse mode). Researchers in Japan used the moderate pulse interval of 205 ps in the burst pulse for high-quality and high-efficiency micromachining of single crystalline sapphire by laser induced plasma assisted ablation (LIPAA). The preceding pulses in the burst generated plasma by ablation of copper placed behind the sapphire substrate, which interacted with the subsequent pulses to induce ablation at the rear surface of sapphire substrates. The ablation quality, efficiency, and the fabrication resolution were […]
Category Archives: Energy harvesting
A 2D ‘antenna’ boosts light emission from carbon nanotubes
Phys.org March 22, 2024 Nanomaterials exhibit excitonic quantum processes occurring at room temperature. However, low dimensionality imposes strict requirements for conventional optical excitation. Researchers in Japan found that exciton transfer in carbon-nanotube/tungsten-diselenide heterostructures occur when alignment could be systematically varied. The mixed-dimensional heterostructures displayed a pronounced exciton reservoir effect where the longer-lifetime excitons within the two-dimensional semiconductor were funneled into carbon nanotubes through diffusion. The new excitation pathway presented several advantages, including larger absorption areas, broadband spectral response, and polarization-independent efficiency. When band alignment was resonant, they observed substantially more efficient excitation via tungsten diselenide compared to direct excitation of […]
Scientists develop an energy-efficient wireless power and information transfer system
Science Daily September 5, 2023 A simultaneous wireless information and power transfer (SWIPT)-enabled nonorthogonal multiple access (NOMA) system has been recognized as a promising technology for enabling the Industrial Internet of Things (IIoT), as it extends the lifetime of small battery-driven sensors. However, its energy efficiency significantly decreases with distance from the central controller. Researchers in South Korea proposed a framework for applying SWIPT-aided NOMA system to a distributed antenna system (DAS) to improve the spectral efficiency and energy efficiency of the IIoT. They optimized the power allocation for the NOMA signaling and power splitting for SWIPT in the DAS […]
Team develops novel sponge-based triboelectric nanogenerator for corrosion protection in transportation systems
Phys.org September 5, 2023 Researchers in China demonstrated highly elastic, and pressure-resistance sponge fabricated TENG capable of adapting to high strength impact in land and water transportation and scalable for any shape for harvesting wave energy and mechanical energy. The sponge had interconnected network and large size ratio of cavity-wall suitable for contact and separation enabled higher output due to the combination of the electronegativity, adhesion, and antioxidant ability. The operation modes provided options for different operating condition and enabled higher output due to the combination of the electronegativity, excellent adhesion, and antioxidant ability… read more. TECHNICAL ARTICLE
Scientists find link between photosynthesis and ‘fifth state of matter’
Science Daily May 3, 2023 Bose-Einstein condensation of excitons enables frictionless energy transfer, but typically occurs under extreme conditions in highly ordered materials, such as graphene double layers. Photosynthetic light-harvesting complexes demonstrate extremely efficient transfer of energy in disordered systems under ambient conditions. Researchers at the University of Chicago established a link between the two phenomena by investigating the potential for exciton-condensate-like amplification of energy transport in room-temperature light harvesting. Using a model of the Fenna-Matthews-Olson complex and accounting for intrachromophore electron correlation explicitly through the addition of multiple sites to the individual chromophores, they observed amplification of the exciton […]
Nanoparticles self-assemble to harvest solar energy
Science Daily February 21, 2023 Most disordered organic polymers are almost incapable of limiting the absorption in the desired cutoff wavelength range, which is detrimental to the design of selective absorbers. An international team of researchers (China, Singapore) reports a scalable selective absorber with a quasiperiodic nanostructure composed by an economical widespread surface self-assembly of densely arranged Fe3O4 nanoparticles, possessing a high-performance energy conversion for low-grade solar energy. By investigating the scale effect of the quasiperiodic densely arranged plasmonic nanostructure, a significant solar absorption >94% and ideal passive suppression of thermal emissivity <0.2 could be obtained simultaneously. With the synergy […]
High-performance and compact vibration energy harvester created for self-charging wearable devices
Science Daily November 29, 2022 Vibration energy harvesters suffer from a significant drop in performance for non-steady-state vibrations, which are important for practical applications. Researchers in Japan demonstrated that the output power under an impulsive force can be increased significantly by placing a U-shaped metal component, called a dynamic magnifier (DM), under a MEMS piezoelectric vibration energy harvester (MEMS-pVEH) with a Pb(Zr,Ti)O3 film. Based on the results of numerical calculations they designed DM to have the same resonant frequency as the MEMS-pVEH and a high mechanical quality factor (). They measured the waveforms of the output voltage of the fabricated […]
Heat-resistant nanophotonic material could help turn heat into electricity
Nanowerk September 22, 2022 A team of researchers in the US (University of Michigan, University of Virginia) has developed materials using destructive interference phenomenon to reflect infrared energy while letting shorter wavelengths pass through. Using pulsed laser, they deposited oxides of calcium and titanium oxides. Oxides made the material more durable, less likely to degrade at high temperature, and they could be more precisely layered. The material controlled the flow of infrared radiation and was stable at temperatures of 2,000 degrees Fahrenheit in air, a nearly twofold improvement over existing approaches. After testing they confirmed that the material worked as […]
Scientists Have Powered a Basic Computer With Just Algae For Over 6 Months
Science Alert May 13, 2022 An international team of researchers (UK, Italy, Norway New Zealand) has developed a bio-photovoltaic energy harvester system using photosynthetic microorganisms on an aluminium anode that can power a microprocessor widely used in Internet of Things applications. The proposed energy harvester has operated the microprocessor for over six months in a domestic environment under ambient light. It is comparable in size to an AA battery, and is built using common, durable, inexpensive, and largely recyclable materials… read more. TECHNICAL ARTICLE
Electronic nanogenerator tattoos as human-machine interfaces
Nanowerk April 19, 2022 Although triboelectric nanogenerators (TENGs) have proven to be excellent candidates for wearable energy harvesters, they commonly face the hurdles of poor adhesion to skin and relative thick in geometry up to several cm. Researchers in China have introduced tattoo-like triboelectric nanogenerators (TL-TENGs) made with ultrathin materials with outstanding mechanical property of high robustness and thickness of tens of μm. They have remarkable electrical characteristics, with open-circuit voltage and short circuit current reaching up to ≈180 V and ≈2.2 μA under constant tapping (≈16 kPa), respectively. With the well structural mechanics designs, the TL-TENGs can be customized […]