Before the development, thin films used in electronic circuits have been designed from synthetic polymers that are derived from petroleum, reports EE Times India. But these films have limitations: their minimal structural resolution is around 20 nanometers and cannot be reduced further.

“This limit has been one of the main obstacles to the development of new generations of very-high-resolution flexible electronic devices,” say the researchers. The collaboration was spearheaded by the Centre National de la Recherche Scientifique. The development was reported in ACS Nano.

Before new generations of microprocessors can be designed, lithography, the technique used for printing electronic circuits, has to be revolutionized to allow for even smaller circuit architecture, reports AzoNano.com. The scientific team, headed by Redouane Borsali, designed a hybrid material, combining sugar-based and petroleum-derived (silicon containing polystyrene) polymers with different physical and chemical properties.

This copolymer is similar to an oil bubble attached to a small water bubble. This type of structure can organize itself into sugar cylinders with a petroleum-based lattice, each structure with a size of five nanometers. The new size would represent a six-fold increase in storage capacity, such as that used in flash drives. Researchers are now trying to improve the control of the lattices’ organization and design in their self-forming structures.

Source: “Thin Copolymer Films to Speed Up Microprocessors,” EE Times India, 5/17/12
Source: “Thin-Film Bio-Copolymer Raises Physical Limit to Microprocessor Performance,” AzoNano.com, 5/13/12
Image by Luestling, used under Fair Use: Reporting.

“Mixing polymers to subgrade soils, instead of the conventional practice of mechanical stabilization, resulted in higher strengths and stiffness than cement and more elasticity,” says Dr. Eyad Masad, a professor in mechanical engineering at the university. He gave a presentation about the development at TAMUQ’s first annual Research-Industry Partnership Showcase.

“Our research findings will contribute to long-lasting and better roads,” Dr. Masad says. The university is talking with Qatar’s public works authority to incorporate the method into infrastructure projects in that country, writes Bonnie James of Gulf Times.

The polymer mixed with subgrade soils decreases the brittleness of the road and prevents it from breaking and cracking because of heavy use. The mixture also reduces the amount of rutting, the creation of grooves, or the sinking of the road surface because of the passage of the vehicles.

“Asphalt roads in Qatar are constructed on loose soil,” Dr. Masad says, one of the reasons for road failure there. Researchers in laboratories at TAMUQ took soil samples used for road construction and mixed them with cement and the polymers. The polymer-mix soils failed only gradually, and extended the lifespan of the road and increased its durability, the researchers say.

If developed commercially, the method could be one of several similar products on the market that use polymers to strengthen roads, such as PolyPavement, Water$ave Flobind, and Ecobond. The products also prevent soil erosion and improve water-wicking capabilities.

Source: “New Design Method for Better Roads,” Gulf Times, 5/22/12
Image by Gyanibash, used under its Creative Commons license.

Their instability means that proteins must be shipped and stored at regulated temperatures, increasing costs. Sometimes they must be discarded because their properties that make them effective degrade. In a study published in the Journal of the American Society of Chemistry, UCLA researchers describe how they synthesized polymers to attach to proteins to stabilize them during shipping and storage.

“Our polymers were synthesized by a controlled radical polymerization technique called reversible addition-fragmentation chain transfer polymerization in order to have end groups that can attach to proteins to form what is called a protein-polymer conjugate,” says Heather Maynard, a UCLA associate professor of chemistry and biochemistry, who worked on the project, in a press release. “We found that the polymers significantly stabilized the protein we used — lysozyme — better to lyophilization (freeze-drying, in which water is removed from the protein) and to heat than did the protein with no additives.”

The polymers are made with a polystyrene backbone and side chains of trehalose, a disaccharide found in various plants and animals that can live for long periods with very little or no water. These chemicals were employed in the 1960s with the popular “Sea Monkeys” kit. When the product was dropped into water, the powder became small shrimp whose long tails were said to resemble those of monkeys. Trehalose is an additive in several protein drug formulations, approved by the U.S. Food and Drug Administration, and known to stabilize proteins when water is removed.

The researchers found that attaching the polymer covalently (forming a protein-polymer conjugate) to the protein stabilized the protein to lyophilization better than adding the non-conjugated polymer at the same concentration. The team also found that the polymers stabilized the protein, lysozyme, significantly better than currently used stabilizers, such as polyethylene glycol, depending on the stress and conditions used.

Source: “UCLA researchers develop way to strengthen proteins with polymers,” UCLA Newsroom, 5/21/12
Image by Bmramon, used under its GNU Free Documentation license.

Graphene is one hundred times stronger than steel. In fact, it’s one of the strongest materials tested by man. Because plastics and polymers are so plentiful in products, graphene-oxide-reinforced polymers could open a new range of light, yet strong, material possibilities, according to a William & Mary press release.

Jaeton Glover, a post-doctoral chemist at William & Mary who helped develop the process, says:

You can make a structure — an airplane wing or a component of a car — and it can give you the strength that you need for your specifications. But, because graphene-reinforced polymers are so light in comparison to metal, there is less material there, there is less weight. And then you start talking about fuel efficiency because you’re pushing less material through the air or on the road.

Glover was the lead author of a paper, titled “In Situ Reduction of Graphene Oxide in Polymers,” that describes how the process was developed. It was published in Macromolecules. Other authors include: Minzhen Cai, a graduate student in applied science; Kyle R. Overdeep, a graduate student in chemistry, now at Johns Hopkins; David E. Kranbuehl, emeritus professor of chemistry;  and Hannes Schniepp, assistant professor of applied science.

Graphene oxide can be manipulated with varying thermal treatments to tap into its intrinsic semiconducting characteristics, Glover says. These properties can be exploited for opto-electronic applications, such as solar cells.

“You can have a pretty fine control on the opto-electronic properties of your material,” Glover says. “Once you do that, we’re getting to the point that we can think about designing new kinds of solar cells or printed microchips, and, well, who knows what else?”

Graphene-oxide also can be manipulated to change the color of the material it is in. Glover notes that such a property isn’t as important as strength and conductivity, but it could be useful for applications, such as windows and roof coatings, where screening of sunlight is desired.

Another benefit of the process is that it can save manufacturers money. Graphene is inexpensive, almost literally dirt cheap, Glover says. Also, incorporating graphene into polymers is relatively environmentally friendly: the process uses, simply, water. No toxic chemicals are required for making the polymer-graphene oxide composite, Glover says. The college has applied for a patent for its process.

Source: “Lighter, stronger, better,” College of William & Mary press release, 5/11/12
Image by Krapnik, used under its Creative Commons license.

The device, called a Flexure-FET biosensor, combines a mechanical sensor that identifies a bio-molecule based on its mass and size with an electrical sensor that identifies molecules based on their electrical charge, according to a Purdue University press release. Researchers claim the device could be several hundred more times more sensitive than other biosensors.

“Individually, both of these types of biosensors have limited sensitivity, but when you combine the two you get something that is better than either,” says Muhammad A. Alam, a Purdue University professor of electrical and computer engineering. The research’s findings are published in the Proceedings of the National Academy of Sciences.

The sensor detects both charged and uncharged bio-molecules, allowing a broader range of applications than either type of sensor alone. One application is in personalized medicine, in which the sensor records an inventory of proteins and DNA from individual patients so that doctors can make more precise diagnostics and treatment decisions.

This medical device also could be deployed to detect cancer and other diseases earlier than other similar tools. The device has this advantage because it can detect small quantities of DNA fragments and proteins deformed by cancer long before the disease is visible through imaging and other methods, Alam says.

The sensor uses a vibrating cantilever, a sliver of silicon that resembles a tiny diving board. The university explains further how the device works:

Located under the cantilever is a transistor, which is the sensor’s electrical part. In other mechanical biosensors, a laser measures the vibrating frequency or deflection of the cantilever, which changes depending on what type of biomolecule lands on the cantilever. Instead of using a laser, the new sensor uses the transistor to measure the vibration or deflection. The sensor maximizes sensitivity by putting both the cantilever and transistor in a ‘bias.’ The cantilever is biased using an electric field to pull it downward as though with an invisible string.

“This pre-bending increases the sensitivity significantly,” says Ankit Jain, a graduate student who helped write the paper. The device can be made to detect almost any molecule as long as the sensor is configured property, Alam adds. The university has applied for a patent.

Source: “Ultrasensitive Biosensor Promising for Medical Diagnostics,” Purdue University press release, 5/14/12
Image by Purdue University, used with permission.

The nanotechnology polymer, polytetrafluoroethylene, is a key component of a trademarked product, Cold-Plus, an oil and bonding agent, that is used on exchanger coil surfaces. The polymer is in the same family of polymers that are used on surfaces of non-stick cookware.

One of the ways the compound is useful is that it limits the reduction of an air conditioners’ capacity. A study in the 1990s by the American Society of Heating, Refrigeration, and Air-Conditioning Engineers found that on average, air-conditioning and refrigeration systems lose 7% cooling capacity in their first year, 5% in their second, and 2% each year thereafter. This means that a five-ton system would produce only four tons of cooling but still consume enough energy to produce five tons of cooling.

The reduction in cooling capacity occurs when refrigeration oil forms a plaque on the exchanger coils. However, that buildup can be reversed by adding  Cold-Plus, reports Refrigerated Transporter. On new systems, the product will prevent the oil buildup from ever occurring. Other benefits include a reduction in the electricity needed to start up the compressor, colder evaporator temperature, better moisture removal, less run time, and less system maintenance.

Refrigerated Transporter discusses other benefits of the product:

Addition of Cold-Plus will increase refrigerant flow 5% to 8% on new and older systems while using slightly less horsepower, and improving heat transfer and efficiency. Cold-Plus is a permanent, one time metal treatment that lasts the life time of the system and prevents restricted or plugged capillary tubes or sticky expansion valves.

Installation of the product requires that the technician be EPA-certified. The installation process takes about 30 minutes. The manufacturer claims increases in performance of the air-conditioning system of between 15% and 20% are common.

Source: “Better Refrigeration, Air-Conditioning Performance Through Nanotechnology,” Refrigerated Transporter, 5/10/12
Image by Achim Hering, used under its Creative Commons license.

The smartphone-turned-into-medical-device is handheld and can continuously monitor a patient’s glucose level, reports ScienceDaily. The device automates much of the work to maintain safe blood sugar levels in diabetics, according to the researchers at the University of Virginia School of Medicine, where the device was created.

The first outpatient, Justin Wood, started his trial in April and says that “the device automates a lot of the tracking and monitoring I do now.” Before the trial started, he used an insulin pump but had to prick his finger five times a day to check his blood sugar level. The device should reduce that need to no more than two times per day. The machine is “a step forward in technology that could change my view and outlook on life,” he says.

Before the trial, Wood had to precisely estimate his food consumption, particularly with carbohydrates, to help properly adjust his insulin supply. But the device automatically read and balanced his blood sugar level. At mealtimes, he entered what he ate to help balance his blood sugar more quickly.

“The operating interface was very slick and very fast,” he says. “The extra second or two you save pressing buttons adds up when you have to do it every day.”

Outpatient testing will continue through 2013 at the University of Virginia and three other locations. Researchers plan to enroll 120 patients in the trial.

Source: “Artificial Pancreas Gets First U.S. Outpatient Test,” ScienceDaily, 5/14/12
Image by Mbbradford, used under Fair Use: Reporting.

A team of researchers built the nanoparticles from a polymer coated with polyethylene glycol, commonly used to deliver drugs within the body because it is nontoxic, writes Infection Control Today. The polymer also is known for its ability to travel through the bloodstream without being detected by the immune system.

An advantage that the nanoparticles have is that they can switch their charge depending on the environment. Previously used nanoparticles were designed to have a positive charge, which is attracted to bacteria’s negatively charged cell walls. However, the body’s immune system tends to clear positively charged nanoparticles from the body before they encounter the bacteria.

Because the new nanoparticles can switch charges, they move in the bloodstream with a negative charge. But when they reach the infection site, they change to a positive charge, allowing them to bind to the bacteria and release the drug.

The environment surrounding bacteria is slightly acidic. Often, antibiotics lose their effectiveness as acidity increases, but the scientists found that their antibiotics carried by the nanoparticles kept their potency better than traditional antibiotics.

The antibiotics release their drug payload over a one- to two-day period. “You don’t want just a short burst of drug because the bacteria can recover once the drug is gone,” says Aleks Radovic-Moreno, an MIT graduate student and one of the researchers, who was the lead author of a paper describing the nanoparticles in the journal, ACS Nano. “You want an extended release of drug so that bacteria are constantly being hit with high quantities of drug until they’ve been eradicated.”

Further research will continue, but the researchers hope that the high doses that can be delivered by the nanoparticles will help overcome bacterial resistance. “When bacteria are drug resistant, it doesn’t mean they stop responding, it means they respond but only at higher concentrations. And the reason you can’t achieve these clinically is because antibiotics are sometimes toxic, or they don’t stay at that site of infection long enough,” Radovic-Moreno says.

Source: “Engineers Design Nanoparticles that Deliver High Doses of Antibiotics Directly to Bacteria,” Infection Control Today, 5/4/12
Image by NIAID/RML, used under Fair Use: Reporting.

Researchers say that the advantages of implanted user interfaces over mobile and wearable user interface (UI) devices include being invisible, impervious to the weather, and never being left behind or forgotten, reports Ken Terry of InformationWeek. The researchers have developed a “powering mat” that recharges the implanted medical device when it is placed on top of the skin.

Using a cadaver, the researchers showed that one can communicate with a small UI device implanted under the skin of an arm. The device could provide sensory output, such as vibrations or sounds, alerting a patient with a pacemaker that the device’s battery is nearly discharged. The scientists also tested pressure and light sensors for entering information.

Current implanted medical devices can only perform tasks that they were programmed to do. However, those with an implanted UI device could support a wide range of applications and tasks, the researchers say. For example, if a pacemaker malfunctions, the implanted UI could reprogram it.

“But that doesn’t mean the person is entirely in control,” says one of the researchers, Christian Holz of the University of Potsdam in Germany. “A lot of these malfunctioning pacemakers can be adjusted by reprogramming them. But so far, there’s no option for anyone but the physician to do it.”

Despite security concerns, the researchers also tested Bluetooth transmissions that could send signals to a care manager or physician. The scientists learned that the data transmissions were hardly affected by the skin covering their UI device.

The researchers have more tests to be conducted before the device can be widely used. For example, they must assess the infection risks of implanted UI devices. Also, it is not clear how patients would react to the devices implanted under their skin.

Source: “Implanted User Interface Gives Patients New Options,” InformationWeek, 5/2/12
Image by KVDP, used by Fair Use: Reporting.

Jyongsik Jang, a polymer scientist at Seoul National Laboratory, says the sensor can detect nerve gas at concentrations as low as 10 parts per trillion, reports Katherine Bourzac of Chemical & Engineering News. With further development, the flexible sensor could mean that it could be worn by those needing to detect chemical weapons, the scientists hope.

The key to the sensor’s effectiveness is its increased surface area caused by the nanostructures. Bourzac explains the manufacturing process:

Jang’s sensors use the inexpensive conductive polymer poly(3,4-ethylenedioxythiophene). When chemists add hydroxyl groups to PEDOT’s sidechains, the polymer can interact with organophosphates via hydrogen bonds. This interaction changes the polymer’s electrical resistance, which simple electronics can easily measure. The more surface area a PEDOT sensor has to interact with gases in the environment, the stronger the response, Jang’s team reasoned. Based on that idea, they wanted to make hydroxylated PEDOT nanostructures to maximize surface area, and in turn produce ultrasensitive sensors.

The manufacturing process starts by electrospinning mats of the polymer to make the nanotubes. Scientists then use vapor to coat the tubes’ surfaces with nanosized nodules. The coating doubles the surface area. Scientists make resistors out of mats of these tubes and place them between two wires on a plastic sheet to give the sensing device flexibility.

To test the sensors, the researchers used dimethyl methylphosphonate, a standard gas used as a stand-in for the nerve gas, sarin. The tubes coated with nanorods performed the best, measuring changes in resistance at concentrations as low as 10 parts per trillion. This ability at detection is two to three orders of magnitude more sensitive than previously reported sensors, Jang says.

Currently, soldiers and police use mass spectroscopy-based devices to detect organophosphates, a group of chemicals that include sarin. Jang’s sensor would be less expensive, more sensitive, and lighter, he says. His team is now developing ways to make the device, with its power source and all other necessary parts, wearable.

One advantage of these sensors is that they can be used continuously because the gas molecules don’t stay bound to the polymer for long, freeing up its detection capacity, says Paul Rhodes, a team manager at the chemical-sensor company, Nanosense.

Source: “A Flexible Nerve-Gas Sensor,” Chemical & Engineering News, 5/9/12
Image by BasilioC, used under Fair Use: Reporting.