applied_physics (23)

SLIPS...

A novel, highly sensitive molecular sensor together with a first-of-its-kind histamine detector comprise abbieSense, a device that can diagnose and assess the severity of an allergic reaction within five minutes. Credit: Wyss Institute at Harvard University

 

Topics: Applied Physics, Fluid Mechanics, Microfluidics, Nanofluidics, Nanotechnology

 


The need for an inexpensive, super-repellent surface cuts across a vast swath of societal sectors—from refrigeration and architecture, to medical devices and consumer products. Most state-of-the-art liquid repellent surfaces designed in the last decade are modeled after lotus leaves, which are extremely hydrophobic due to their rough, waxy surface and the physics of their natural design. However, none of the lotus-inspired materials designed so far has met the mark: they may repel water but they fail to repel oils, fail under physical stress, cannot self-heal – and are expensive to boot.

‘SLIPS’ technology, inspired by the slippery pitcher plant that repels almost every type of liquid and solid, is a unique approach to coating industrial and medical surfaces that is based on nano/microstructured porous material infused with a lubricating fluid. By locking in water and other fluids, SLIPS technology creates slick, exceptionally repellent and robust self-cleaning surfaces on metals, plastics, optics, textiles and ceramics. These slippery surfaces repel almost any fouling challenge a surface may face—whether from bacteria, ice, water, oil, dust, barnacles, or other contaminants.

 

Wyss Institute, Harvard: Slippery Liquid Infused Porous Surfaces

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Superconductors' never-ending flow of electrical current could provide new options for energy storage and superefficient electrical transmission and generation. But the signature zero electrical resistance of superconductors is reached only below a certain critical temperature and is very expensive to achieve. Physicists in Serbia believe they've found a way to manipulate superthin, waferlike monolayers of superconductors, thus changing the material's properties to create new artificial materials for future devices. This image shows a liquid phase graphene film deposited on PET substrate. Credit: Graphene Laboratory, University of Belgrade

 

Topics: Applied Physics, Superconductors, Thin Films


Superconductors' never-ending flow of electrical current could provide new options for energy storage and superefficient electrical transmission and generation, to name just a few benefits. But the signature zero electrical resistance of superconductors is reached only below a certain critical temperature, hundreds of degrees Celsius below freezing, and is very expensive to achieve.

Physicists from the University of Belgrade in Serbia believe they've found a way to manipulate superthin, waferlike monolayers of superconductors, such as graphene, a monolayer of carbon, thus changing the material's properties to create new artificial materials for future devices. The findings from the group's theoretical calculations and experimental approaches are published in the Journal of Applied Physics.

"The application of tensile biaxial strain leads to an increase of the critical temperature, implying that achieving high temperature superconductivity becomes easier under strain," said the study's first author from the University of Belgrade's LEX Laboratory, Vladan Celebonovic.

 

Strain enables new applications of 2-D materials, Phys.org

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Good Vibes...

Sounding off: theoretical force patterns for an underwater Chladni plate at two different frequencies. The force arrows illustrate why glass beads accumulate at the plate antinodes (shown in yellow and red). (Courtesy: K Latifi, H Wijaya and Q Zhou/Physical Review Letters)

 

Topics: Acoustic Physics, Applied Physics, Research


The behaviour of some particles on the vibrating surfaces of Chladni plates is reversed underwater, a new study reveals. The discovery was made by Kourosh Latifi, Harri Wijaya, and Quan Zhou at Aalto University in Finland. They observed that glass beads on a submerged vibrating plate move towards antinodes, where the plate’s amplitude of vibration is highest. The underwater effect could be useful in a variety of medical and biological applications, including the manipulation of living cells.

In 1787 the German physicist Ernst Chladni put sand on a vibrating plate and observed that the grains settle on the nodal lines where the plate’s amplitude of vibration is zero. In contrast, he observed that finer particles move towards the plate’s antinodes where the amplitude is a local maximum.

A century later, Michael Faraday explained both behaviours. He concluded that the vibrations cause the larger grains to move laterally across the plate until they reach a node – where they no longer get lateral kicks and therefore remain in place. As for why the smaller particles did the opposite, Faraday argued that air currents just above the plates tend to push the lighter particles towards the antinodes – an effect known as acoustic streaming.

 

Vibrations guide tiny glass beads through an underwater maze
Sam Jarman, Physics World

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