Human brain's ultimate barrier to open for first time - health - 18 June 2014 - New Scientist

Human brain's ultimate barrier to open for first time - health - 18 June 2014 - New Scientist: Next is a treatment called high-intensity focused ultrasound. The volunteers will wear a cap that contains an array of transducers that direct ultrasound waves into their brain. Just as the sun's rays can be focused by a magnifying glass, ultrasound waves can be concentrated inside the body to get the microbubbles to vibrate.

The vibrating bubbles will expand and contract about 200,000 times a second, which will force apart the endothelial cells that form the BBB. The idea is that this will allow the chemotherapy drug in the bloodstream to sneak through the gaps in the barrier and into any nearby tumour cells...

Watch a singularity form in a stretchy soap film - physics-math - 28 May 2014 - New Scientist

Watch a singularity form in a stretchy soap film - physics-math - 28 May 2014 - New Scientist

Air bubbles could be the secret to artificial skin

Air bubbles could be the secret to artificial skin: On a uniform elastomeric substrate, traction tests revealed the creation of micro-fissures in the metallic layer, which would eventually result in the rupture of the conducting network. But with foam substrates, these cracks only occurred above the air bubbles. "Between the bubbles, the metal remained intact. The conducting network is thus maintained and can function," she explains. "Our measurements showed that we could achieve a level of elasticity over 100% without disrupting the network. These metallic pathways built upon foam could thus be used as electrodes, sensors or interconnections for the electronic skin that we're developing."

Video: Micro-Robots Made of Bubbles That Are Powered by Lasers | Popular Science

Video: Micro-Robots Made of Bubbles That Are Powered by Lasers | Popular Science: Using nothing more than a fine-tipped syringe filled with air and saline solution, Ohta and his colleagues in the U.H. Department of Electrical Engineering have created a system that uses a 400 mW infrared laser to propel bubbles around their environment. The laser is shone straight through the bubble, where it heats the far side...
The velocity of the bubbles correlates to the intensity of the laser, so speed can be manipulated by dialing the laser up or down...
Unlike other micromechanical machines, which are often controlled by magnetic fields, they are also independently steerable--each bubble simply requires its own laser source. Where a swarm of microbots controlled via magnetism would tend to clump together as they respond to a common magnetic field, the laser-controlled bubble-bots can be steered separately with an array of infrared lasers.

colloidaldisplay

colloidaldisplay: We developed an ultra thin and flexible BRDF screen using the mixture of two colloidal liquids. There have been several researches on dynamic BRDF display in the past. However, our work is different in several points. Our membrane screen can be controlled using ultrasonic vibrations. Membrane can change its transparency and surface states depending on the scales of ultrasonic waves. Based on these facts, we developed several ap- plications of the membranes such as 3D volume screen.
The combination of the ultrasonic waves and ultra thin membranes makes more realistic, distinctive, and vivid imageries on screen. This system contributes to open up a new path for display engineering with sharp imageries, transparency, BRDF and flexibility.

Engineers use short ultrasound pulses to reach neurons through blood-brain barrier

Engineers use short ultrasound pulses to reach neurons through blood-brain barrier: Up until now, scientists have thought that long ultrasound pulses, which can inflict collateral damage, were required. But in this new study, the Columbia Engineering team show that extremely short pulses of ultrasound waves can open the blood-brain barrier -- with the added advantages of safety and uniform molecular delivery -- and that the molecule injected systemically could reach and highlight the targeted neurons non invasively...
Konofagou and her team have designed a focused ultrasound method that can target only the area of the hippocampus that is affected in early Alzheimer's. In this study, they administered microbubbles to enhance the intended mechanical effect, and a high-field MRI to detect and map the area of BBB opening as well as quantify the permeability of the opened BBB...
The blood-brain barrier has been shown to recover within the range of three hours to three days depending on the aforementioned parameters used...

Bubbles exhibit weird sandy behaviour - physics-math - 30 April 2011 - New Scientist

Bubbles exhibit weird sandy behaviour: To investigate whether bubbles behave in a similar way, Rémi Lespiat and his colleagues at the University of Paris-East in France squirted nitrogen gas into a chamber of water and monitored the resulting bubbles' passage through a tube.
At low densities, the bubbles flowed. But when they filled 64 per cent of the tube, they jammed just like the grains (Physical Review Letters, DOI: 10.1103/PhysRevLett.106.148302). The result suggests there may be a universal rule that kicks in when objects fill 64 per cent of a space.

Sonic doom: Making a sound barrier - tech - 01 March 2011 - New Scientist

Sonic doom: Making a sound barrier: Sonic crystals are really not much more than arrangements of objects that scatter sound waves, but they have one very alluring feature: with careful design they can stop sound dead...
The key to this effect lies in the spacing between pipes. If incoming sound waves have a wavelength roughly equal to the distance between any two pipes, the sounds are reflected and interfere destructively...
Physicist Juan Sánchez-Pérez at UPV is aiming for a similar effect by using pipes of different diameters arranged in a pattern based on a fractal arrangement called a Sierpinski triangle...

Pop goes the plasma: extreme conditions inside imploding bubbles | Engineering at Illinois

Pop goes the plasma: extreme conditions inside imploding bubbles | Engineering at Illinois: "High-intensity ultrasound waves traveling through liquid leave bubbles in their wake. Under the right conditions, these bubbles implode spectacularly, emitting light and reaching very high temperatures, a phenomenon called sonoluminescence. Researchers have observed imploding bubble conditions so hot that the gas inside the bubbles ionizes into plasma, but quantifying the temperature and pressure properties has been elusive.

Plasma emission from collapsing bubbles: The imploding bubbles move around after each collapse, tracing out a lit path, like a person flinging their arm around while holding a flashlight.
In a paper published in the June 27 issue of Nature Physics, University of lllinois professor Kenneth S. Suslick and former student David Flannigan, now at the California Institute of Technology, experimentally determine the plasma electron density, temperature and extent of ionization."