Posts Tagged ‘Virginia Tech’

Nonfood to food: transforming cellulose

Thursday, April 18th, 2013

With concerns about having enough food to feed everyone, the news that researchers from Virginia Tech have found a way to transform cellulose into starch is encouraging. From the Apr. 17, 2013 news item on Azonano,

A team of Virginia Tech researchers has succeeded in transforming cellulose into starch, a process that has the potential to provide a previously untapped nutrient source from plants not traditionally thought of as food crops.

Y.H. Percival Zhang, an associate professor of biological systems engineering in the College of Agriculture and Life Sciences and the College of Engineering, led a team of researchers in the project that could help feed a growing global population that is estimated to swell to 9 billion by 2050. Starch is one of the most important components of the human diet and provides 20-40 percent of our daily caloric intake.

The Apr. 15, 2013 Virginia Tech news release, which originated the news item, describes cellulose and some of the other benefits to be had from transforming it into starch,

Cellulose is the supporting material in plant cell walls and is the most common carbohydrate on earth. This new development opens the door to the potential that food could be created from any plant, reducing the need for crops to be grown on valuable land that requires fertilizers, pesticides, and large amounts of water. The type of starch that Zhang’s team produced is amylose, a linear resistant starch that is not broken down in the digestion process and acts as a good source of dietary fiber. It has been proven to decrease the risk of obesity and diabetes.

This discovery holds promise on many fronts beyond food systems.

“Besides serving as a food source, the starch can be used in the manufacture of edible, clear films for biodegradable food packaging,” Zhang said.  “It can even serve as a high-density hydrogen storage carrier that could solve problems related to hydrogen storage and distribution.”

The news release goes on to provide details about the new process,

“Cellulose and starch have the same chemical formula,” Zhang said. “The difference is in their chemical linkages. Our idea is to use an enzyme cascade to break up the bonds in cellulose, enabling their reconfiguration as starch.”

The new approach takes cellulose from non-food plant material, such as corn stover, converts about 30 percent to amylose, and hydrolyzes the remainder to glucose suitable for ethanol production. Corn stover consists of the stem, leaves, and husk of the corn plant remaining after ears of corn are harvested. However, the process works with cellulose from any plant.

This bioprocess called “simultaneous enzymatic biotransformation and microbial fermentation” is easy to scale up for commercial production. It is environmentally friendly because it does not require expensive equipment, heat, or chemical reagents, and does not generate any waste. The key enzymes immobilized on the magnetic nanoparticles can easily be recycled using a magnetic force.

Zhang designed the experiments and conceived the cellulose-to-starch concept. Zhang and Virginia Tech visiting scholar Hongge Chen are the inventors of the cellulose-to-starch biotransformation, which is covered under a provisional patent application. [emphasis mine] Chun You, a postdoctoral researcher from China at Virginia Tech, and Chen conducted most of the research work.

I think we’re still a long way from being able to munch on corn stalks instead of corn. Also, it’s with some interest I note the researchers’ patent application. Exactly what are they trying to patent?

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Posted in agriculture, food, nanotechnology | No Comments »

It takes more than research to change energy sources and use

Thursday, February 14th, 2013

Much of the talk about reducing or eliminating dependency on fossil fuels is focused on research to accomplish these goals or policies to support and promote new patterns of energy use as opposed to the details needed to implement a change in the infrastructures. For example, one frequently sees news about various energy research efforts such as this one at the University of Texas at Dallas featured in a Feb. 14, 2013 news item on Azonano,

University of Texas at Dallas researchers and their colleagues at other institutions are investigating ways to harvest energy from such diverse sources as mechanical vibrations, wasted heat, radio waves, light and even movements of the human body.

The goal is to develop ways to convert this unused energy into a form that can self-power the next generation of electronics, eliminating or reducing the need for bulky, limited-life batteries.

Beyond the more familiar wind and solar power, energy harvesting has a wide range of potential applications. These include: powering wireless sensor networks placed in “intelligent” buildings, or in hard-to-reach or dangerous areas; monitoring the structural health of aircraft; and biomedical implants that might transmit health data to your doctor or treat a chronic condition.

The Feb. 14, 2013 University of Texas at Dallas news release, which originated the news item, describes a recent energy research event and highlights some of the work being performed by the Center for Energy Harvesting Materials and Systems (CEHMS) consortium (Note: A link has been removed),

At a recent scientific conference held at UT Dallas, experts from academia, industry and government labs gathered to share their latest research on energy harvesting. Energy Summit 2013 focused on research initiatives at UT Dallas, Virginia Tech and Leibniz University in Germany, which form a consortium called the Center for Energy Harvesting Materials and Systems (CEHMS).

Founded in 2010, CEHMS is an Industry/University Cooperative Research Center funded in part by the National Science Foundation. It includes not only academic institutions, but also corporate members who collaborate on research projects and also provide funding for the center.  Roger Nessen, manager of sales and marketing at Exelis Inc. is chairman of the CEHMS advisory board.

Here are some examples of the research,

For example, Dr. Mario Rotea, the Erik Jonsson Chair and head of the Department of Mechanical Engineering at UT Dallas, discussed some of his work aimed at advancing the development of wind energy systems. He represents UT Dallas in a proposed new consortium of universities and companies called WindSTAR that would collaborate with CEHMS on wind energy science and technology issues.

On the chemistry front, Smith’s [Dennis Smith, co-director of CEHMS and the Robert A. Welch Distinguished Chair in Chemistry at UT Dallas] synthetic chemistry lab is working with advanced materials that use piezoelectrics. If a piezoelectric material is deformed by a mechanical stress – such as stepping on it or subjecting it to vibrations – it produces an electric current. Smith’s lab is investigating whether the addition of nanoparticles to certain piezoelectric materials can boost this so-called piezoelectric effect.

CEHMS co-director Dr. Shashank Priya, professor of mechanical engineering and the James and Elizabeth Turner Fellow of Engineering at Virginia Tech, collaborates with Smith on piezoelectric research. Among many projects, researchers at Virginia Tech are incorporating piezoelectrics into “smart” tiles that produce electricity when stepped upon, as well as into materials that might be applied like wallpaper to gather light and vibrational energy from walls.

Other university and industry projects include:

  • Investigating how to redesign systems to require less power.
  • An intelligent tire system that harvests energy from the vibrations in a rotating tire, powering embedded sensors that gather and report data on tire pressure, tire conditions and road conditions.
  • A new class of magnetoelectric materials that can simultaneously convert magnetic fields and vibrations into energy.
  • A textile-type material that converts wasted thermal energy into electricity, which could be wrapped around hot pipes or auto exhaust pipes to generate power.
  • Flexible solar cells that could be integrated into textiles, and worn by hikers or soldiers to power portable electronic devices far away from an electric socket.

It’s exciting to talk about research, startups, and policies but at some point one needs to develop an infrastructure to support these efforts as Kyle Vanhemert points out (in an elliptical fashion) in his Feb.14, 2013 article, A Deeply Thought-Out Plan for EV [electric vehicle] Charging Stations, on the Fast Company website,

Currently, the best estimates suggest that upwards of 80% of electric vehicle charging happens at home. … If we want to see wider adoption of EVs, however, one thing is obvious: We need to make it possible for drivers to charge in places other than their garage. It’s a more complex problem than it might seem, but a series of reports by the New York-based architecture and design studio WXY will at least give urban planners and prospective charging station entrepreneurs a place to start.

The studies, sponsored by the U.S. Department of Energy and the New York State Energy Research and Development Authority, address a major obstacle standing in the way of more ubiquitous charging–namely, that no one knows exactly what ubiquitous charging looks like. And in fairness, that’s because it doesn’t look like any one thing.  …

The WXY design studio has developed guidelines for these hypothetical EV charging stations,

The study identifies 22 design elements in all, divided into three categories: installation, access, and operation. The first looks at the infrastructural nuts and bolts of the site, including factors like physical dimensions of the station and its proximity to the power grid. Access deals with the factors that shape the basic user experience, things like proximity to traffic and building entrances, lighting, and signage. …

Vanhemert’s article includes some design diagrams, more details about these charging stations, and links to the design studio’s report and other reports that have been commissioned for the US Northeast Electric Vehicle Network.

Thank you to Kyle Vanhemert for a thought-provoking article, which raises questions about what kinds of changes will need to be made to infrastructure and everyday gadgets as we transition to new energy sources.

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Posted in energy, science policy | No Comments »

It really is a nanoscale window into the biological world

Friday, December 21st, 2012

The researchers at Virginia Tech Carilion Research Institute (VTC Research Institute) have sandwiched together a couple of chips, each with a hole (window) in the middle giving themselves a peek into biological processes as they occur, they hope. Here’s a more technical explanation from the Dec. 20, 2012 news release on EurekAlert,

Investigators at the Virginia Tech Carilion Research Institute have invented a way to directly image biological structures at their most fundamental level and in their natural habitats. The technique is a major advancement toward the ultimate goal of imaging biological processes in action at the atomic level.

…

The technique involves taking two silicon-nitride microchips with windows etched in their centers and pressing them together until only a 150-nanometer space between them remains. The researchers then fill this pocket with a liquid resembling the natural environment of the biological structure to be imaged, creating a microfluidic chamber.

Then, because free-floating structures yield images with poor resolution, the researchers coat the microchip’s interior surface with a layer of natural biological tethers, such as antibodies, which naturally grab onto a virus and hold it in place.

The lead researcher describes the difference between the usual imaging techniques and their newly developed technique (from the EurekAlert news release),

“It’s sort of like the difference between seeing Han Solo frozen in carbonite and watching him walk around blasting stormtroopers,” said Deborah Kelly, an assistant professor at the VTC Research Institute and a lead author on the paper describing the first successful test of the new technique. “Seeing viruses, for example, in action in their natural environment is invaluable.”

Ken Kingery’s Dec. ??, 2012 Virginia Tech Carilion Research Institute article, which originated the news release, describes the specific virus the researchers used the ‘window’ to spy on,

Rotavirus is the most common cause of severe diarrhea among infants and children. By the age of five, nearly every child in the world has been infected at least once. And although the disease tends to be easily managed in the developed world, in developing countries rotavirus kills more than 450,000 children a year.

At the second step in the pathogen’s life cycle, rotavirus sheds its outer layer, which allows it to enter a cell, and becomes what is called a double-layered particle. Once its second layer is exposed, the virus is ready to begin using the cell’s own infrastructure to produce more viruses. It was the viral structure at this stage that the researchers imaged in the new study.

Kelly and McDonald [Sarah McDonald, an assistant professor at the VTC Research Institute] coated the interior window of the microchip with antibodies to the virus. The antibodies, in turn, latched onto the rotaviruses that were injected into the microfluidic chamber and held them in place. The researchers then used a transmission electron microscope to image the prepared slide.

The technique worked perfectly.

The experiment gave results that resembled those achieved using traditional freezing methods to prepare rotavirus for electron microscopy, proving that the new technique can deliver accurate results. “It’s the first time scientists have imaged anything on this scale in liquid,” said Kelly.

There’s more to work to be done of course as the researchers refine the technique and try to ‘spy’ on more of the processes. In the meantime, the paper about this latest imaging research will be published in print in 2013 or it can be viewed online now (this is a open access article in a journal published by the Royal Society of Chemistry [RSC], you will need to sign up but this too is free),

Visualizing viral assemblies in a nanoscale biosphere
Brian L. Gilmore ,  Shannon P. Showalter ,  Madeline J. Dukes ,  Justin R. Tanner ,  Andrew C. Demmert ,  Sarah M. McDonald and Deborah F. Kelly

Lab Chip, 2013,13, 216-219

DOI: 10.1039/C2LC41008G Received 15 Jun 2012, Accepted 13 Nov 2012 First published on the web 19 Nov 201

 

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Posted in medicine, nanotechnology | No Comments »

Robotic sea jellies (jellyfish) and carbon nanotubes

Friday, March 23rd, 2012

After my recent experience at the Vancouver Aquarium (Jan.19.12 posting) where I was informed that jellyfish are now called sea jellies, I was not expecting to see the term jellyfish still in use. I gather the new name is not being used universally yet, which explains the title for a March 23, 2012 news item on Nanowerk, Robotic jellyfish built on nanotechnology,

Researchers at The University of Texas at Dallas and Virginia Tech have created an undersea vehicle inspired by the common jellyfish that runs on renewable energy and could be used in ocean rescue and surveillance missions.

In a study published this week in Smart Materials and Structures (“Hydrogen-fuel-powered bell segments of biomimetic jellyfish”), scientists created a robotic jellyfish, dubbed Robojelly, that feeds off hydrogen and oxygen gases found in water.

“We’ve created an underwater robot that doesn’t need batteries or electricity,” said Dr. Yonas Tadesse, assistant professor of mechanical engineering at UT Dallas and lead author of the study. “The only waste released as it travels is more water.”

Engineers and scientists have increasingly turned to nature for inspiration when creating new technologies. The simple yet powerful movement of the moon jellyfish made it an appealing animal to simulate.

The March 22, 2012 press release from the University of Texas at Dallas features images and a video in addition to its text. From the press release,

The Robojelly consists of two bell-like structures made of silicone that fold like an umbrella. Connecting the umbrella are muscles that contract to move.

Here’s a computer-aided image,

A computer-aided model of Robojelly shows the vehicle's two bell-like structures.

Here’s what the robojelly looks like,

The Robojelly, shown here out of water, has an outer structure made out of silicone.

This robojelly differs from the original model,which was battery-powered. Here’s a video of the original robojelly,

The new robojelly has artificial muscles(from the Mar. 22, 2012 University of Texas at Dallas press release),

In this study, researchers upgraded the original, battery-powered Robojelly to be self-powered. They did that through a combination of high-tech materials, including artificial muscles that contract when heated.

These muscles are made of a nickel-titanium alloy wrapped in carbon nanotubes, coated with platinum and housed in a pipe. As the mixture of hydrogen and oxygen encounters the platinum, heat and water vapor are created. That heat causes a contraction that moves the muscles of the device, pumping out the water and starting the cycle again.

“It could stay underwater and refuel itself while it is performing surveillance,” Tadesse said.

In addition to military surveillance, Tadesse said, the device could be used to detect pollutants in water.

This is a study that has been funded by the US Office of Naval Research. At the next stage, researchers want to make the robojelly’s legs work independently so it can travel in more than one direction.

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Posted in biomimcry, environment, military, nanotechnology | 1 Comment »