Engineers at Yale Univ. have discovered that the stiffness of liquid drops embedded in solids has something in common with Goldilocks: While large drops of liquids are softer than the solid that surrounds them, extremely tiny drops of liquid can actually be stiffer than certain solids. But when they’re “just right,” the liquid drops have the exact same stiffness as the surrounding solid.
How does glass transition from a liquid to its familiar solid state? How does this common...
Tiny, soapy bubbles can reorganize their membranes to let material flow in and out in response...
Helium is a famously unreactive gas but when cooled to just above absolute zero it becomes a...
Scientists at Nanyang Technology University (NTU) in Singapore have developed a new type of lithium-ion battery in which the traditional graphite used for the anode has been replaced with a new gel material made from titanium dioxide. The new design allows the battery to endure more than 10,000 cycles, vs. about 500 recharge cycles for typical rechargeable lithium-ion batteries.
Axons are the shafts of neurons, on the tips of which connections are made with other neurons or cells. In a new study in Texas, researchers were able to use microfluidic stimulations to change the path of an axon at an angle of up to 90 degrees. The publication adds insight to the long accepted idea that chemical cues are primarily responsible for axonal pathfinding during human development and nervous system regeneration.
Massachusetts Institute of Technology researchers have developed a new way of creating surfaces on which droplets of any desired shape can spontaneously form. They say this approach could lead to new biomedical assay devices and light-emitting diode display screens, among other applications. The new work represents the first time that scientists can control the shape of the contact area of the droplets.
Mathematicians from Brown Univ. have introduced a new element of uncertainty into an equation used to describe the behavior of fluid flows. Ironically, allowing uncertainty into a mathematical equation that models fluid flows makes the equation much more capable of correctly reflecting the natural world, including the formation, strength, and position of air masses and fronts in the atmosphere.
Droplets are simple spheres of fluid, not normally considered capable of doing anything on their own. But now researchers have made droplets of alcohol move through water, even moving through complex mazes. The droplets can be led to certain targets, using a surprisingly simple impetus. In the future, such moving droplets may deliver medicines, moving entire chemistries to targets.
As tech company LG demonstrated this summer with the unveiling of its 18-in flexible screen, the next generation of roll-up displays is tantalizingly close. Researchers are now reporting a new, inexpensive and simple way to make transparent, flexible transistors that could help bring roll-up smartphones with see-through displays and other bendable gadgets to consumers in just a few years.
Transforming substances from liquids into gels plays an important role across many industries, but the transformation process, called gelation, is expensive and energy demanding. Instead of adding chemical thickeners and heating or cooling the fluids, as is traditional, researchers in Okinawa are experimenting with microfluidic platforms, adding nanoparticles and biomolecules with used pH, chemical and temperature sensing properties.
Researchers from North Carolina State Univ. have developed a technique for controlling the surface tension of liquid metals by applying very low voltages, opening the door to a new generation of reconfigurable electronic circuits, antennas and other technologies. The technique hinges on the fact that the oxide “skin” of the metal acts as a surfactant, lowering the surface tension between the metal and the surrounding fluid.
Using an "electric prism", or deflector, scientists have found a new way of separating water molecules that differ only in their nuclear spin states and, under normal conditions, do not part ways. Since water is such a fundamental molecule in the universe, the recent study may impact a multitude of research areas ranging from biology to astrophysics.
A mechanical engineering student at EPFL in Switzerland wanted to understand the reason behind the formation of a “foam volcano” after tapping the neck of a bottle of beer. He studied the phenomenon with a high-speed camera and compared it to the outcome of applying the same action to sparkling water. His work offers insights into the behavior of cavitation nuclei.
A new study has investigated the effects of small but finite inertia on the propulsion of micro- and nano-scale swimming machines. Scientists have found that the direction of propulsion made possible by such inertia is opposite to that induced by a viscoelastic fluid. The findings could help to optimize the design of swimming machines to improve their mobility in medical applications.
More than a decade ago, news of a Namibian desert beetle’s efficient water collection system inspired engineers to try and reproduce these surfaces in the laboratory. Small-scale advances in fluid physics, materials engineering and nanoscience since that time have brought them close to succeeding. And their work could have impact on a wide range of industries at the macroscale.
Recent research shows that, in the presence of charged substances, water molecules favor associating with elements with a negative electrical charge rather than a positive electric charge. A study on the subject that employed advanced optical spectroscopy techniques could provide new insights on the processes of cell formation.
Using something called a microchannel heat sink to simulate the warm environment of a working computer, researchers in Malaysia have analyzed three nanofluids for the traits that are important in an effective coolant. The results of their study show that the nanofluids, which are made of metallic nanoparticles that have been added to a liquid, such as water, all performed better than water as coolants, with one mixture standing out.
Known as the “world's longest experiment”, an experiment at the University of Queensland in Australia was famous for taking ten years for a drop of pitch, a black, sticky material, to fall from a funnel. A new test in the U.K. is using a different bitumen, or pitch, which is 30 times less viscous than the Queensland experiment, so that the flow can be seen at a faster rate and hopefully provide more insights.
Whenever there is a major spill of oil into water, the two tend to mix into a suspension of tiny droplets, called an emulsion, that is extremely hard to separate and can cause severe damage to ecosystems. A new membrane developed by Massachusetts Institute of Technology researchers can separate even these highly mixed fine oil-spill residues.
Physicists in Europe have solved a mystery that has puzzled scientists for half a century. it has long been known that the distance between the graphene oxide layers depends on the humidity, not the actual amount of water added. But now, with the help of powerful microscopes, it can be seen how distance between graphite oxide layers gradually increases when water molecules are added, and why this phenomenon occurs.
A physicist in Russia, Alexander Rozhkov, has presented theoretical calculations which indicate the possible existence of fermionic matter in a previously unknown state. It is defined as a 1-D liquid, which cannot be described within the framework of existing models. According to Rozhkov, the 1-D liquid state of matter is not necessarily one that can be observed with the naked eye on a macroscopic scale.
Simple solid-state lasers consist of only one material. But quantum cascade lasers are made of a perfectly optimized layer system of different materials so the wavelength of the laser can be tuned. Now a method has been developed in Austria to create a laser and a detector at the same time, on one single chip, in such a way that the wavelength of the laser perfectly matches the wavelength to which the detector is sensitive.
Essential oils have boomed in popularity as more people seek out alternatives to replace their synthetic cleaning products, anti-mosquito sprays and medicines. Now scientists are tapping them as candidates to preserve food in a more consumer-friendly way. Recent research has led to new edible films containing oils from clove and oregano that preserve bread longer than commercial additives.
Bacteria use threadlike appendages, called pili, to creep along a surface, and some disease-causing microbes extend pili in all directions to move. But until now researchers have been unable to explain why bacteria like these are able to travel in a straight line consistently. A new model developed to describe this movement shows that bacteria do not act as randomly as they appear to when moving.
Although lubricants for machinery are widely used, almost no fundamental innovations for this type of product has been made in the last 20 years, according researchers in Germany who have been working on a new class of lubricating substance. Their new liquid crystalline lubricant enable nearly frictionless sliding because although it is a liquid, the molecules display directional properties like crystals do.
Brigham Young Univ. engineering professors Julie Crockett and Dan Maynes have created a sloped channel that is super-hydrophobic, and causes water to bounce like a ball as it rolls down the ramp. Their recent study finds surfaces with a pattern of microscopic ridges or posts, combined with a hydrophobic coating, produces an even higher level of water resistance, depending on how the water hits the surface.
A simple new technique to form interlocking beads of water in ambient conditions could prove valuable for applications in biological sensing, membrane research and harvesting water from fog. Researchers have developed a method to create air-stable water droplet networks known as droplet interface bilayers. These interconnected water droplets have many roles in biological research because their interfaces simulate cell membranes.
Scientists at Rice Univ. have mixed very low concentrations of diamond nanoparticles with mineral oil to test the nanofluid’s thermal conductivity and how temperature would affect its viscosity. They found it to be much better than nanofluids that contain higher amounts of oxide, nitride or carbide ceramics, metals, semiconductors, carbon nanotubes and other composite materials. In short, it is the best nanofluid for heat transfer.
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