Engineered surface unsticks sticky water droplets

The leaves of the lotus flower, and other natural surfaces that repel water and dirt, have been the model for many types of engineered liquid-repelling surfaces. As slippery as these surfaces are, however, tiny water droplets still stick to them. Now, Penn State Univ. researchers have developed nano/micro-textured, highly slippery surfaces able to outperform these naturally inspired coatings, particularly when the water is a vapor or tiny droplets.

Enhancing the mobility of liquid droplets on rough surfaces could improve condensation heat transfer for power-plant heat exchangers, create more efficient water harvesting in arid regions, and prevent icing and frosting on aircraft wings.

“This represents a fundamentally new concept in engineered surfaces,” said Tak-Sing Wong, assistant professor of mechanical engineering and a faculty member in the Penn State Materials Research Institute. “Our surfaces combine the unique surface architectures of lotus leaves and pitcher plants in such a way that these surfaces possess both high surface area and a slippery interface to enhance droplet collection and mobility. Mobility of liquid droplets on rough surfaces is highly dependent on how the liquid wets the surface. We have demonstrated for the first time experimentally that liquid droplets can be highly mobile when in the Wenzel state.”

Liquid droplets on rough surfaces come in one of two states: Cassie, in which the liquid partially floats on a layer of air or gas, and Wenzel, in which the droplets are in full contact with the surface, trapping or pinning them. The two states are named for the physicists who first described them. While the Wenzel equation was published in 1936 in a highly cited paper, it has been extremely challenging to verify the equation experimentally.

“Through careful, systematic analysis, we found that the Wenzel equation does not apply for highly wetting liquids,” said Birgitt Boschitsch Stogin, graduate student in Wong’s group and co-author of “Slippery Wenzel State,” published online in ACS Nano.

“Droplets on conventional rough surfaces are mobile in the Cassie state and pinned in the Wenzel state. The sticky Wenzel state results in many problems in condensation heat transfer, water harvesting and ice removal. Our idea is to solve these problems by enabling Wenzel state droplets to be mobile,” said Xianming Dai, postdoctoral scholar in Wong’s group and the lead author on the paper.

In the last decade, tremendous efforts have been devoted to designing rough surfaces that prevent the Cassie-to-Wenzel wetting transition. A key conceptual advance in the current study is that both Cassie- and Wenzel-state droplets can retain mobility on the slippery rough surface, foregoing the difficult process of preventing the wetting transition.

In order to make Wenzel state droplets mobile, the researchers etched micrometer scale pillars into a silicon surface using photolithography and deep reactive-ion etching, and then created nanoscale textures on the pillars by wet etching. They then infused the nanotextures with a layer of lubricant that completely coated the nanostructures, resulting in greatly reduced pinning of the droplets. The nanostructures also greatly enhanced lubricant retention compared to the microstructured surface alone.

The same design principle can be easily extended to other materials beyond silicon, such as metals, glass, ceramics and plastics. The authors believe this work will open the search for a new, unified model of wetting physics that explains wetting phenomena on rough surfaces.

Source: Penn State Univ.

The Mac Pro Can Run Six 4K Monitors at 60Hz With Just the Built-In Graphics Cards

YouTube tech reviewer Adam Matthews has discovered that the Mac Pro is capable of driving six 4K monitors using just the built-in graphics cards.

Since Apple lists the Mac Pro as only supporting three 4K monitors, Matthews went about developing a custom external solution to support the additional three monitors. He purchased a Corsair CX750 power supply, an AMD7970 GPU, and a Sonnet case to make it happen.

Supposedly the Mac Pro 2013 trash can can only support 3 x 4k monitors so i built an external GPU (eGPU) via thunderbolt. It uses the Sonnet Thunderbolt chassis and in this case an AMD 7970 GPU. Although you can use GTX970, GTX 980, Titan etc. This is how i did it.

To Matthews’ surprise when he tried to plug his six Dell P715Q displays into the Mac Pro directly, it actually ran all six at 60Hz.

Android smartwatches get in time with iPhone

SAN FRANSISCO: Google on Monday broke down the wall between Android smart watches and iPhones, taking on Apple Watch on its home turf.

A version of Android Wear smart watch software tailored for Apple’s mobile operating system made its debut, paired for now only with LG Watch Urbane, according to a Google blog post.

“Today, Android Wear for iOS works with the LG Watch Urbane,” Google said.

“All future Android Wear watches, including those from Huawei, Asus, and ..

Read more at:

How to spot a psychopath

August 31, 2015

An article in International Business Times (UK) says recent studies show that there are other indicators of psychopathy aside from the classic lack of empathy.

Researchers say contagious yawning is a sign of empathy, and that psychopaths are less likely to yawn after seeing someone else yawn. Another clue is an impaired sense of smell, and certain speech patterns.

The article mentions a related UBC study, which found that psychopaths tended to use the past tense in describing their crime, and used more “uhms” and “ahs.”


Particles don’t obey the same rules as people. Poke a particle, and another one far away can instantly respond the touch — without any messages passing through the space between, as if the two particles were one. “Entanglement” is what quantum physics calls the intimate connection.
Einstein called it “spooky.” To his dying day, he refused to believe that nature could be so unreasonable.
But a new research paper from the Netherlands might have convinced even the father of relativity that he was wrong. Posted online on August 24, it describes the first experiment that meets the mathematical gold standard for proving entanglement, set down more than half a century ago. The paper hasn’t yet gone through peer review; it’s currently under review at a scientific journal, but it’s already causing a stir in the quantum physics community.
To his dying day, Einstein refused to believe that nature could be so unreasonable.
“It’s a shame that Einstein didn’t live long enough to learn about this,” say Christoph Simon, a theoretical quantum physicist at the University of Calgary in Alberta, Canada. “The universe is not as reasonable as he wanted it to be.”
The Quantum Quest
The idea that two seemingly separate objects can fuse into a single quantum entity dates to the 1930s or earlier. But it wasn’t until 1964 that physicist John Stewart Bell first pinned down the criteria for entanglement. A groundbreaking paper he published in an obscure journal set statistical limits on how particles can behave in relation to each other without defying the physics governing life at human scales.
It would take nearly two decades for researchers making pairs of light particles in France to find, for the first time, behavior that violated this limit. For many, that was proof enough that the particles had been entangled.
But there were problems. Because of limits on their light detectors, some of the French particles had gone missing. Also the photons had been kept close enough together to, perhaps, pass secret messages. Skeptics of entanglement pointed out the loopholes and suggested other hidden factors at work.
“Extraordinary claims require extraordinary evidence,” says Matthew Leifer, a theoretical quantum physicist at the Perimeter Institute for Theoretical Physics in Waterloo, Ontario, Canada. “Most quantum physicists such as myself have been fully convinced that entanglement exists, but there are a few people out there with alternative theories.”
“Extraordinary claims require extraordinary evidence.”
In the late 90s a team in Vienna separated entangled photons by hundreds of meters, far enough to fix the distance problem. At the beginning of the 21st century, U.S. scientists built instruments good enough to keep track of nearly all the charged atoms they tried to rope together, closing the detection loophole. But until now no one had devised a single, iron-clad experiment that addresses both limitations at the same time.
“There’s been a race going on, with several groups trying to do this,” says Simon.
Diamond In The Rough

Photo of entangled photons
Paul Kwiat, University of Illinois at Urbana-Champaign and Michael Reck, University of Vienna
Ronald Hanson had an eye for diamonds. The gems he and his team favors at the Delft University of Technology in the Netherlands are deliberately imperfect. Synthesized the lab, they contain defects housing unentangled electrons.
For their latest experiment, the Dutch scientists placed two diamond chips more than three-quarters of a mile apart in different buildings on campus. Photons shot into the defects entangled themselves with the electrons. Those photons then traveled over fiber optic cables and met in a third building, where the researchers attempted to entangle them. When they succeeded, the electrons back in the diamonds swapped partners and become entangled with each other, as confirmed with measurements made on the defects.
Thanks to the ease of keeping track of the electrons and the great distance made possible by the traveling photons, the experiment seems to have closed both loopholes.
An Unhackable Internet?
What excites [Chris Monroe], an experimental quantum physicist at the Joint Quantum Institute in Maryland, about the loophole-free Bell test is its usefulness for a new kind of communications network, a quantum version of the Internet. Entangled particles sent over such a network would be protected against hackers; an eavesdropper could not tap into the information without making her presence known.
“The security of the information is guaranteed by the fundamental laws of physics,” says Monroe.
Whether such networks, if ever developed, will need to be made of diamond remains to be seen. During its nine-day run, Hanson’s glittering contraption popped out a mere 245 pairs of entangled particles. A commercially viable system would need to spit out thousands or more a minute.
With only 245 events, statistics dictates a four percent chance that the result was due to chance, meaning that Bell’s threshold may not have actually been crossed.
“In other words, there’s a 96 percent chance that they won the race,” says Paul Kwiat, an experimental quantum physicist who works with photons and is also in the race at the University of Illinois at Urbana-Champaign. “The nail’s not very deep in the coffin, and I’m certain that before long there will be results that have a much lower statistical uncertainty.

Google Maps Turned Into Cool Generative Art By Boston-Based Coder

A Boston-based computer coder has turned his hand to modifying the Google Maps API to produce some very cool generative art.

Shaun Utter has created a site that automatically generates scenes from a host of predetermined cities, colouring them in shocking fluorescent tones.

Generative art is produced automatically and often employs computer coding to take data – in this case Google’s mapping files – and to invert colour palletes or produce visual effects.

Read more: Dreamscope App Uses Google’s Deep Dream To Make Really Cool Photo Filters

And many of the scenes are familiar to city dwellers the world over…

London is one of the cities used as part of the site

The images morph into another scene every four seconds

A wide variety of colours are used

Many of the scenes appear to echo modern art

Street scenes like this one produce brightly coloured images

Scientists find how obesity gene works, a clue to treatment

Scientists have finally figured out how the key gene tied to obesity makes people fat, a major discovery that could open the door to an entirely new approach to the problem beyond diet and exercise.
The work solves a big mystery: Since 2007, researchers have known that a gene called FTO was related to obesity, but they didn’t know how, and could not tie it to appetite or other known factors.

Now experiments reveal that a faulty version of the gene causes energy from food to be stored as fat rather than being burned. Genetic tinkering in mice and on human cells in the lab suggests this can be reversed, giving hope that a drug or other treatment might be developed to do the same in people.
The work was led by scientists at MIT and Harvard University and published online by the New England Journal of Medicine.
The discovery challenges the notion that “when people get obese it was basically their own choice because they choose to eat too much or not exercise,” said study leader Melina Claussnitzer, a genetics specialist at Harvard-affiliated Beth Israel Deaconess Medical Center. “For the first time, genetics has revealed a mechanism in obesity that was not really suspected before” and gives a third explanation or factor that’s involved.
Independent experts praised the discovery.
“It’s a big deal,” said Dr. Clifford Rosen, a scientist at Maine Medical Center Research Institute and an associate editor at the medical journal.
“A lot of people think the obesity epidemic is all about eating too much,” but our fat cells play a role in how food gets used, he said. With this discovery, “you now have a pathway for drugs that can make those fat cells work differently.”
Several obesity drugs are already on the market, but they are generally used for short-term weight loss and are aimed at the brain and appetite; they don’t directly target metabolism.
Researchers can’t guess how long it might take before a drug based on the new findings becomes available. But it’s unlikely it would be a magic pill that would enable people to eat anything they want without packing on the pounds. And targeting this fat pathway could affect other things, so a treatment would need rigorous testing to prove safe and effective.
The gene glitch doesn’t explain all obesity. It was found in 44 percent of Europeans but only 5 percent of Blacks, so other genes clearly are at work, and food and exercise still matter.
Having the glitch doesn’t destine you to become obese but may predispose you to it.