Oil spill cleanup by sponge: Madison scientists tout tidy technology

By Thomas Content of the Journal Sentinel

In a development arising from nanotechnology research, scientists in Madison have created a spongelike material that could provide a novel and sustainable way to clean up oil spills.

It's known as an aerogel, but it could just as well be called a "smart sponge."

To demonstrate how it works, researchers add a small amount of red dye to diesel, making the fuel stand out in a glass of water. The aerogel is dipped in the glass and within minutes, the sponge has soaked up the diesel. The aerogel is now red, and the glass of water is clear.

"It was very effective," said Shaoqin "Sarah" Gong, who runs a biotechnology-nanotechnology lab at the Wisconsin Institute for Discovery in Madison.

"So if you had an oil spill, for example, the idea is you could throw this aerogel sheet in the water and it would start to absorb the oil very quickly and efficiently," said Gong, a University of Wisconsin-Madison associate professor of biomedical engineering. "Once it's fully saturated, you can take it out and squeeze out all the oil."

The material's absorbing capacity is reduced somewhat after each use, but the product "can be reused for a couple of cycles," Gong said.

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Research Paves Path for Hybrid Nano-Materials That Could Replace Human Tissue or Today's Pills

Brooklyn, New York—A team of researchers has uncovered critical information that could help scientists understand how protein polymers interact with other self-assembling biopolymers. The research helps explain naturally occurring nano-material within cells and could one day lead to engineered bio-composites for drug delivery, artificial tissue, bio-sensing, or cancer diagnosis.

Results of this study, “Bionanocomposites: Differential Effects of Cellulose Nanocrystals on Protein Diblock Copolymers,” were recently published in the American Chemical Society’s BioMacromolecules. The findings were the result of a collaborative research project from the Polytechnic Institute of New York University (NYU-Poly) Montclare Lab for Protein Engineering and Molecular Design under the direction of Associate Professor of Chemical and Biomolecular Engineering Jin K. Montclare.

Bionanocomposites provide a singular area of research that incorporates biology, chemistry, materials science, engineering, and nanotechnology. Medical researchers believe they hold particular promise because—unlike the materials that build today’s medical implants, for example—they are biodegradable and biocompatible, not subject to rejection by the body’s immune defenses. As biocomposites rarely exist isolated from other substances in nature, scientists do not yet understand how they interact with other materials such as lipids, nucleic acids, or other organic materials and on a molecular level. This study, which explored the ways in which protein polymers interact with another biopolymer, cellulose, provides the key to better understanding how biocomposite materials would interact with the human body for medical applications.

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Nanoparticles could power 'electronic skin' in the future

By Devin Coldewey

July 10, 2013

A new development in nanotechnology may enable "electronic skin" for robots and prosthetic limbs, offering sensitivity not just to pressure, but to humidity and temperature — and it's even flexible.

The new material is developed by chemical engineers at the Israel Institute of Technology, who found that a certain type of gold nanoparticle changed how it conducted electricity based on pressure.

These nanoparticles are only 5-8 nanometers in diameter, comprising a gold core and a spiky, protective outer layer. When sandwiched into a special film, the way that film is bent or pressed may cause the nanoparticles to spread out or bunch together, changing how well electricity passes between them.

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Institute of Bioengineering and Nanotechnology, IBM reveal new antimicrobial hydrogel

Researchers from IBM (NYSE: IBM) and the Institute of Bioengineering and Nanotechnology revealed today an antimicrobial hydrogel that can break through diseased biofilms and completely eradicate drug-resistant bacteria upon contact. The synthetic hydrogel, which forms spontaneously when heated to body temperature, is the first-ever to be biodegradable, biocompatible and non-toxic, making it an ideal tool to combat serious health hazards facing hospital workers, visitors and patients.

Traditionally used for disinfecting various surfaces, antimicrobials can be found in traditional household items like alcohol and bleach. However, moving from countertops to treating drug resistant skin infections or infectious diseases in the body are proving to be more challenging as conventional antibiotics become less effective and many household surface disinfectants are not suitable for biological applications.

IBM Research and its collaborators developed a remoldable synthetic antimicrobial hydrogel, comprised of more than 90% water, which, if commercialized, is ideal for applications like creams or injectable therapeutics for wound healing, implant and catheter coatings, skin infections or even orifice barriers.

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Nanotech patent jungle set to become denser in 2013

17 January 2013

Simon Hadlington

As we welcome in 2013, will nanotechnology continue to dominate many of the scientific headlines in the coming year, just as it has done over the past decade? The huge activity across nanotechnology in recent years, reflected in an ever-increasing number of patents, suggests that it will.

In 2012 the US patent office published some 4000 patents under its class ‘977 – nanotechnology’. This was a record, up from 3439 the previous year, 2770 in 2010 and 1449 in 2009.

Do these figures herald an exciting dawn of technological innovation based around components measured at the atomic and molecular scale? Emphatically not and on the contrary, argues Joshua Pearce, who runs the Open Sustainability Technology lab at Michigan Technological University in the US. The problem is that in the rush to patent potentially lucrative new discoveries, a forest of broad and overlapping patents have been filed around the world by commercial and academic researchers. If someone wishes to develop a new product that uses single-walled carbon nanotubes, for example, there is a dense ‘thicket’ of hundreds of patents to be negotiated.

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Nano-infused paint can detect strain

Mike Williams

Rice University’s fluorescent nanotube coating can reveal stress on planes, bridges, buildings A new type of paint made with carbon nanotubes at Rice University can help detect strain in buildings, bridges and airplanes.

The Rice scientists call their mixture “strain paint” and are hopeful it can help detect deformations in structures like airplane wings. Their study, published online this month by the American Chemical Society journal Nano Letters details a composite coating they invented that could be read by a handheld infrared spectrometer.

This method could tell where a material is showing signs of deformation well before the effects become visible to the naked eye, and without touching the structure. The researchers said this provides a big advantage over conventional strain gauges, which must be physically connected to their read-out devices. In addition, the nanotube-based system could measure strain at any location and along any direction.

Rice chemistry professor Bruce Weisman led the discovery and interpretation of near-infrared fluorescence from semiconducting carbon nanotubes in 2002, and he has since developed and used novel optical instrumentation to explore nanotubes’ physical and chemical properties.

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Nanotechnology could recover energy

WEST LAFAYETTE, Ind., April 17 (UPI) -- U.S. researchers say a new technique could harvest energy from hot pipes or engine components to recover energy wasted in factories, power plants and cars.

Scientists at Purdue University say they've used nanotechnology techniques to coat glass fibers with a new "thermoelectric" material they developed.

When thermoelectric materials are heated on one side, electrons flow to the cooler side, generating an electrical current.

Fibers treated in this manner could be wrapped around industrial pipes in factories and power plants, as well as on car engines and automotive exhaust systems, to recapture much of the wasted energy, the researchers said.

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Nanotube therapy takes aim at breast cancer stem cells

WINSTON-SALEM, N.C. – Feb. 9, 2012 – Wake Forest Baptist Medical Center researchers have again proven that injecting multiwalled carbon nanotubes (MWCNTs) into tumors and heating them with a quick, 30-second laser treatment can kill them.

The results of the first effort involving kidney tumors was published in 2009, but now they've taken the science and directed it at breast cancer tumors, specifically the tumor initiating cancer stem cells. These stem cells are hard to kill because they don't divide very often and many anti-cancer strategies are directed at killing the cells that divide frequently.

The Wake Forest Baptist research findings are reported online ahead of April print publication in the journal Biomaterials. The research is a result of a collaborative effort between Wake Forest School of Medicine, the Wake Forest University Center for Nanotechnology and Molecular Materials, and Rice University. Lead investigator and professor of biochemistry Suzy V. Torti, Ph.D., of Wake Forest Baptist, said the breast cancer stem cells tend to be resistant to drugs and radiotherapy, so targeting these particular cells is of great interest in the scientific community.

"They are tough. These are cells that don't divide very often. They just sort of sit there, but when they receive some sort of trigger – and that's not really well understood – it's believed they can migrate to other sites and start a metastasis somewhere else," Torti explained. "Heat-based cancer treatments represent a promising approach for the clinical management of cancers, including breast cancer."

Link to the study.


A Single Cell Endoscope Berkeley Lab Researchers Use Nanophotonics for Optical Look Inside Living Cells

An endoscope that can provide high-resolution optical images of the interior of a single living cell, or precisely deliver genes, proteins, therapeutic drugs or other cargo without injuring or damaging the cell, has been developed by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab). This highly versatile and mechanically robust nanowire-based optical probe can also be applied to biosensing and single-cell electrophysiology.

A team of researchers from Berkeley Lab and the University of California (UC) Berkeley attached a tin oxide nanowire waveguide to the tapered end of an optical fibre to create a novel endoscope system. Light travelling along the optical fibre can be effectively coupled into the nanowire where it is re-emitted into free space when it reaches the tip. The nanowire tip is extremely flexible due to its small size and high aspect ratio, yet can endure repeated bending and buckling so that it can be used multiple times.

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Carbon nanotube muscles generate giant twist for novel motors

Twist per muscle length is over a thousand times higher than for previous artificial muscles and the muscle diameter is ten times smaller than a human hair.

New artificial muscles that twist like the trunk of an elephant, but provide a thousand times higher rotation per length, were announced on Oct. 13 for a publication in Science magazine by a team of researchers from The University of Texas at Dallas, The University of Wollongong in Australia, The University of British Columbia in Canada, and Hanyang University in Korea.

These muscles, based on carbon nanotubes yarns, accelerate a 2000 times heavier paddle up to 590 revolutions per minute in 1.2 seconds, and then reverse this rotation when the applied voltage is changed. The demonstrated rotation of 250 per millimeter of muscle length is over a thousand times that of previous artificial muscles, which are based on ferroelectrics, shape memory alloys, or conducting organic polymers. The output power per yarn weight is comparable to that for large electric motors, and the weight-normalized performance of these conventional electric motors severely degrades when they are downsized to millimeter scale.

These muscles exploit strong, tough, highly flexible yarns of carbon nanotubes, which consist of nanoscale cylinders of carbon that are ten thousand times smaller in diameter than a human hair. Important for success, these nanotubes are spun into helical yarns, which means that they have left and right handed versions (like our hands), depending upon the direction of rotation during twisting the nanotubes to make yarn. Rotation is torsional, meaning that twist occurs in one direction until a limiting rotation results, and then rotation can be reversed by changing the applied voltage. Left and right hand yarns rotate in opposite directions when electrically charged, but in both cases the effect of charging is to partially untwist the yarn.

Unlike conventional motors, whose complexity makes them difficult to miniaturize, the torsional carbon nanotube muscles are simple to inexpensively construct in either very long or millimeter lengths. The nanotube torsional motors consist of a yarn electrode and a counter-electrode, which are immersed in an ionically conducting liquid. A low voltage battery can serve as the power source, which enables electrochemical charge and discharge of the yarn to provide torsional rotation in opposite directions. In the simplest case, the researchers attach a paddle to the nanotube yarn, which enables torsional rotation to do useful work – like mixing liquids on "micro-fluidic chips" used for chemical analysis and sensing.

The mechanism of torsional rotation is remarkable. Charging the nanotube yarns is like charging a supercapacitor - ions migrate into the yarns to electrostatically balance the electronic charge electrically injected onto the nanotubes. Although the yarns are porous, this influx of ions causes the yarn to increase volume, shrink in length by up to a percent, and torsionally rotate. This surprising shrinkage in yarn length as its volume increases is explained by the yarn's helical structure, which is similar in structure to finger cuff toys that trap a child's fingers when elongated, but frees them when shortened.

Nature has used torsional rotation based on helically wound muscles for hundreds of millions of years, and exploits this action for such tasks as twisting the trunks of elephants and octopus limbs. In these natural appendages, helically wound muscle fibers cause rotation by contracting against an essentially incompressible, bone-less core. On the other hand, the helically wound carbon nanotubes in the nanotube yarns are undergoing little change in length, but are instead causing the volume of liquid electrolyte within the porous yarn to increase during electrochemical charging, so that torsional rotation occurs.

The combination of mechanical simplicity, giant torsional rotations, high rotation rates, and micron-size yarn diameters are attractive for applications, such as microfluidic pumps, valve drives, and mixers. In a fluidic mixer demonstrated by the researchers, a 15 micron diameter yarn rotated a 200 times larger radius and 80 times heavier paddle in flowing liquids at up to one rotation per second.

"The discovery, characterization, and understanding of these high performance torsional motors shows the power of international collaborations", said Ray H. Baughman, a corresponding author of the author of the Science article and Robert A. Welch Professor of Chemistry and director of The University of Texas at Dallas Alan G. MacDiarmid NanoTech Institute. "Researchers from four universities in three different continents that were born in eight different countries made critically important contributions."

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