material sciences

5 things you didn’t know about...robot skin

Credit: Cornell University

1.  A technology has been developed allowing robots to feel their surroundings internally – similar to how humans do.

2. The core and the outer surface of the waveguide, which houses the LED and the photodiode, were produced through a four-step lithography process

3. The photodiode detects loss of light through the core as the robot hand moves. This variable amount of light allows the hand to feel its surroundings.

4. The hand is able to grasp objects and sense shape and texture. The team used it to scan three tomatoes and decide which was the ripest based on softness.

5. It has potential uses in prosthetics and orthotics.

Find out more about this on page 9 of the February issue of Materials World, or go to the Materials World website.

Materials science for Minecraft

Credit: University of Texas, Dallas.

Researchers at the University of Texas, USA, have created an alternative tool for teaching their students about materials science. Their creation, Polycraft World, is a mod for the video game Minecraft that features petrochemical refining and harvesting of new ore types, and the construction of polymers, plastics and specialty items. 

The team says that the students can learn, and try, 2,000 production methods to make over 100 polymers in game, including processed such as distillation, chemical synthesis and various manufacturing processes.

Polycraft uses Minecraft to approach a university-level subject in a way that even those who have not studied it before can take apart and begin to learn the ins-and-outs of materials science.

This supercapacitor battery can be recharged 30,000 times

A thin, flexible supercapacitor boasts high energy and power densities. Credit: University of Central Florida

Everyone and anyone with a smartphone know it is not long before your phone holds a charge for less and less time as the battery begins to degrade. But new research by scientists at the NanoScience Technology Center at the University of Central Florida (UCF), USA, could change that. The team have developed a new method for producing flexible supercapacitors that can store greater amounts of energy and can be recharged over 30,000 times without degradation. This new method could transform technology such as electric vehicles and mobile phones in the future.

‘If you were to replace the batteries with these supercapacitors, you could charge your mobile phone in a few seconds and you wouldn’t need to charge it again for over a week,’ said University of Central Florida researcher Nitin Choudhary.

The UCF team has attempted to apply newly discovered 2D materials that measure just a few atoms thick to supercapacitors. Other scientists have also tried formulations with other 2D materials including graphene, but had only limited success. The new supercapacitors are composed of millions of nanometre-thick wires coated with shells of 2D materials. The core facilitates the super-fast charging and discharging that makes supercapacitors powerful, and the 2D coating delivers the energy storage ability.

‘We developed a simple chemical synthesis approach so we can very nicely integrate the existing materials with the two-dimensional materials,’ said Yeonwoong Eric Jung, assistant professor of the study. Jung is working with UCF’s Office of Technology Transfer to patent the new process. ‘It’s not ready for commercialisation,’ Jung said. ‘But this is a proof-of-concept demonstration, and our studies show there are very high impacts for many technologies.’

Three uranium minerals found

The uranyl mineral leószilárdite. Credit: Travis Olds

Scientists discovered three new uranium minerals, or uranyl minerals, growing on the walls of an abandoned uranium mine in Utah, USA. The three new minerals, discovered by researchers at Michigan Technological University, USA,  leesite, leószilárdite and redcanyonite, are uranium oxide compounds, born of reactions between uranium and oxygen. 

Manganese and ammonium give redcanyonite a slightly darker than the other two newly discovered uranyl mineral.

The mineral leesite is bright yellow with blade-like crystals up to 1mm long arranged in stacks. It is a member of the schoepite mineral family, discovered in the Jomac Mine. Leószilárdite (as seen above) was discovered in the Markey Mine in Utah’s Red Canyon. It is a carbonate mineral with bladed crystals of a slightly paler yellow colour, and can partly dissolve in water. 

When uranium-rich ores interact with water and air they form bright yellow crystalline minerals, as seen with leesit. 

The third mineral, redcanyonite, is a striking yellow colour and was found in the Blue Lizard Mine, also in the Red Canyon. It is structurally similar to the uranium mineral zippeite, also found in old uranium mines. Redcanyonite is the rarest of the finds, and can only form where there is manganese as well as rock rich in organic material.

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First Aid Advance for Serious Trauma

Researchers are reporting a new sprayable foam that can stop major internal or external bleeding without needing to compress the wound, a first-aid advance desperately needed by first responders and trauma surgeons. 

Whether a person suffers a major injury in an auto accident or on the battlefield, one of the leading causes of death is blood loss. The National Trauma Institute says hemorrhage leads to 35 percent of all deaths that occur before an injured patient gets to a hospital. It is responsible for 40 percent of all trauma-related deaths in the first 24 hours. 

Now bioengineers and scientists at the University of Maryland, College Park and Massachusetts General Hospital say they have created a polymer-based foam that causes blood cells to clump together. Learn more below.

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More Than You Ever Wanted to Know About Mechanical Engineering: Latent Heat

Let’s look in detail at the process of boiling a pure substance.

We’ll start out with a compressed liquid. We’ll say it’s water at 25 deg C. Moreover, let’s say it’s contained in a cylinder with a piston so that the pressure inside the cylinder is always at atmospheric pressure.

If we start heating up the cylinder, the water inside will expand slightly. The pressure will remain constant as the piston moves with the water’s expansion. Once we get to 100 deg C, the water exists as a saturated liquid - any additional heat will cause it to vaporize.

If we keep adding heat to it, things get interesting. The water will start to boil. It’s volume will increase drastically, but its temperature will remain the same. All the energy you’re putting into it is going into the phase change. The amount of energy it takes to go from a liquid to a vapor is called the latent heat of vaporization. (Similarly, the amount of heat it takes for a solid to melt into a liquid is the latent heat of fusion.)  So while the water in your cylinder is in the process of boiling, it exists as a mixture of saturated liquid and saturated vapor. Its temperature will remain at a constant 100 deg C throughout the process. Although its apparent volume will increase, its specific volume - the volume per unit mass - will also remain constant.

Once all the water has been vaporized, if you continue adding heat to the cylinder, the water will start to rise in temperature again and its specific volume will start to increase. In this state, it exists as a superheated vapor.

The entire process we just described looks like this.

Note that this show temperature vs. specific volume for only one pressure - if we varied the pressure as well, things would look quite different. The interdependence of temperature, volume, and pressure will be important in our analysis of thermodynamic processes.

Dual-function nanorod LEDs could make multifunctional displays

Cellphones and other devices could soon be controlled with touchless gestures and charge themselves using ambient light, thanks to new LED arrays that can both emit and detect light.

Made of tiny nanorods arrayed in a thin film, the LEDs could enable new interactive functions and multitasking devices. Researchers at the University of Illinois at Urbana-Champaign and Dow Electronic Materials in Marlborough, Massachusetts, report the advance in the Feb. 10 issue of the journal Science.

“These LEDs are the beginning of enabling displays to do something completely different, moving well beyond just displaying information to be much more interactive devices,” said Moonsub Shim, a professor of materials science and engineering at the U. of I. and the leader of the study. “That can become the basis for new and interesting designs for a lot of electronics.”

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Making graphene with soybeans

A team of scientists at CSIRO claim to have made graphene more commercially viable using soybean oil. The new ‘GraphAir’ technology eliminates the need for a highly-controlled environment by growing graphene film in air with a natural precursor, making its production faster and simpler.

GraphAir transforms soybean oil into graphene films in a single step. With heat, soybean oil breaks down into a range of carbon building units that are essential for the synthesis of graphene. The team also transformed other types of renewable and even waste oil, such as those leftover from barbecues or cooking, into graphene films. 

‘We can now recycle waste oils that would have otherwise been discarded and transform them into something useful,’ said CSIRO scientist Dr Dong Han Seo.

The potential applications of this technology include water filtration and purification, renewable energy, sensors, as well as, personalised healthcare and medicine. 

New, long-lasting flow battery could run for more than a decade with minimum upkeep

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a new flow battery that stores energy in organic molecules dissolved in neutral pH water. This new chemistry allows for a non-toxic, non-corrosive battery with an exceptionally long lifetime and offers the potential to significantly decrease the costs of production.

The research, published in ACS Energy Letters, was led by Michael Aziz, the Gene and Tracy Sykes Professor of Materials and Energy Technologies and Roy Gordon, the Thomas Dudley Cabot Professor of Chemistry and Professor of Materials Science.

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