Articles tagged with "energy-harvesting"
Tiny turbines crack wind’s secret ‘twist’ for a giant 37% power boost
Researchers led by Shuo Zhang have discovered that pairing two tiny, counter-rotating wind turbines in tandem can increase power output by 37% compared to a single turbine. These micro wind turbines, less than 200 millimeters in diameter, are crucial for powering remote and decentralized technologies such as environmental sensors and IoT devices. Using stereoscopic particle image velocimetry, a 3D airflow visualization technique, the team analyzed the wake—turbulent airflow—behind the first turbine and found it retains significant rotational energy typically lost. By positioning a second turbine counter-rotating behind the first at a specific distance (12 radii), this residual rotational energy can be harnessed, boosting overall efficiency. The enhanced performance stems from the unique physics of small turbines, which operate at lower speeds and higher torque, imparting a “twist” to the wind that the downstream turbine can exploit. This tandem design mimics multi-stage turbines in jet engines by capturing both the wind’s push and twist
energywind-turbinesmicro-wind-turbinesrenewable-energyenergy-harvestingIoT-devicessustainable-powerUS scientists shatter 165-year-old physics rule for energy breakthroughs
A research team at Penn State has reported a groundbreaking violation of Kirchhoff’s law of thermal radiation, a fundamental physics principle established 165 years ago. Kirchhoff’s law states that a material’s ability to absorb energy at a specific wavelength and angle must equal its ability to emit energy under the same conditions. However, the Penn State scientists demonstrated a significant non-reciprocity contrast of 0.43—indicating a notable difference between absorptivity and emissivity—using a specially designed five-layer thin film semiconductor structure. This effect was observed over a broad 10-micrometer wavelength range, marking the strongest recorded deviation from the law’s reciprocity principle. This breakthrough has important implications for energy harvesting and thermal management technologies. For example, conventional solar cells must emit some absorbed energy back to the sun, which limits their efficiency. The new non-reciprocal material can direct emitted energy away from the sun, potentially allowing that energy to be captured by additional solar cells and thus improving overall
energythermal-radiationKirchhoff's-lawnon-reciprocitythin-film-materialsenergy-harvestingsemiconductor-materialsPhysicists create world’s smallest violin that’s thinner than hair
materialsnanotechnologynanolithographyelectronicsenergy-harvestingprecision-engineeringmicrofabricationUS scientists harvest electrical energy from human movement
energytriboelectric-generatorenergy-harvestingwearable-biosensorsmechanical-energypower-generationsensors