'Active' Surfaces Control How Particles Move

Researchers at MIT and in Saudi Arabia have developed a new way of making surfaces that can actively control how fluids or particles move across them. The work might enable new kinds of biomedical or microfluidic devices, or solar panels that could automatically clean themselves of dust and grit.The system makes use of a microtextured surface, with bumps or ridges just a few micrometers across, that is then impregnated with a fluid that can be manipulated — for example, an oil infused with tiny magnetic particles, or ferrofluid, which can be pushed and pulled by applying a magnetic field to the surface. When droplets of water or tiny particles are placed on the surface, a thin coating of the fluid covers them, forming a magnetic cloak.The thin magnetized cloak can then actually pull the droplet or particle along as the layer itself is drawn magnetically across the surface. Tiny ferromagnetic particles, approximately 10 nanometers in diameter, in the ferrofluid could allow precision control when it’s needed — such as in a microfluidic device used to test biological or chemical samples by mixing them with a variety of reagents. Unlike the fixed channels of conventional microfluidics, such surfaces could have “virtual” channels that could be reconfigured at will.The new approach could be useful for a range of applications: For example, solar panels and the mirrors used in solar-concentrating systems can quickly lose a significant percentage of their efficiency when dust, moisture, or other materials accumulate on their surfaces. But if coated with such an active surface material, a brief magnetic pulse could be used to sweep the material away.Source Also: Read more Materials tech briefs.

Posted in: News, Energy, Renewable Energy, Solar Power, Fluid Handling, Drug Delivery, Medical, Motion Control


Solar Refrigerators Store Life-Saving Vaccines

NASA’s battery-free solar technology powers vaccine refrigerators in hot, rural communities. NASA’s photovoltaic (PV) technology has advanced many of its missions. This renewable source of energy is produced when certain photo-emissive materials, such as silicon, eject electrons upon absorbing photons from sunlight. These free electrons can be captured, and the resulting current can be used as electricity. NASA first used solar power in 1958 when Vanguard 1 was successfully launched into space.

Posted in: Articles, Energy, Solar energy, Medical, health, and wellness


Spongelike Structure Converts Solar Energy into Steam

A new material structure developed at MIT generates steam by soaking up the sun.The structure — a layer of graphite flakes and an underlying carbon foam — is a porous, insulating material structure that floats on water. When sunlight hits the structure’s surface, it creates a hotspot in the graphite, drawing water up through the material’s pores, where it evaporates as steam. The brighter the light, the more steam is generated.The new material is able to convert 85 percent of incoming solar energy into steam — a significant improvement over recent approaches to solar-powered steam generation.“Steam is important for desalination, hygiene systems, and sterilization,” says Hadi Ghasemi, a postdoc in MIT’s Department of Mechanical Engineering, who led the development of the structure. “Especially in remote areas where the sun is the only source of energy, if you can generate steam with solar energy, it would be very useful.”SourceAlso: See other Energy tech briefs.

Posted in: News, Energy, Energy Harvesting, Solar Power, Materials


Hurricane-Tracking Unmanned Systems Win NASA Challenge

NASA has selected three winning designs solicited to address the technological limitations of the uncrewed aerial systems (UAS) currently used to track and collect data on hurricanes. Engineering teams at Virginia Polytechnic Institute and State University, Purdue University, and the University of Virginia were named first- through third-place winners, respectively, of the agency's 2013-2014 University Aeronautics Engineering Design Challenge.

Posted in: News, Aerospace, Aviation, Alternative Fuels, Environmental Monitoring, Automation, Robotics, Data Acquisition, Measuring Instruments, Monitoring, Test & Measurement


New Fuel Cells Increase Airplane Efficiency

Washington State University researchers have developed the first fuel cell that can directly convert fuels, such as jet fuel or gasoline, to electricity, providing a dramatically more energy-efficient way to create electric power for planes or cars.

Posted in: News, Energy, Energy Efficiency


New Study Uses Blizzard to Measure Wind Turbine Airflow

A study by researchers at the University of Minnesota using snow during a Minnesota blizzard is giving researchers new insight into the airflow around large wind turbines. This research is essential to improving wind energy efficiency, especially in wind farms where airflows from many large wind turbines interact with each other. As wind turbines have grown to more than 100 meters tall, field research in real-world settings has become more difficult.

Posted in: News, Energy, Energy Efficiency, Wind Power, Imaging, Video, Visualization Software, Optics, Photonics, Measuring Instruments, Test & Measurement


Gas Flow Measurement Technology Packs Hundreds of Sensors Into One Optical Fiber

By fusing together the concepts of active fiber sensors and high-temperature fiber sensors, a team of researchers at the University of Pittsburgh has created an all-optical high-temperature sensor for gas flow measurements that operates at record-setting temperatures above 800 °C. This technology is expected to find industrial sensing applications in harsh environments ranging from deep geothermal drill cores to the interiors of nuclear reactors to the cold vacuum of space missions, and it may eventually be extended to many others.

Posted in: News, Aerospace, Energy, Geothermal Power, Fiber Optics, Optics, Photonics, Detectors, Sensors, Measuring Instruments, Test & Measurement


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