Research in Brief

Taming the divas of the nanoworld

Physicist Yoke Khin Tap has discovered how to grow carpets of boron nitride nanotubes on substrates of simple catalysts.
Image Courtesy of Yoke Khin Yap

Boron nitride nanotubes are the divas of the nanoworld. In possession of alluring properties, they are also notoriously temperamental.

On the plus side, they can withstand incredibly high heat, well over 1,100 degrees Celsius, says Yoke Khin Yap, an associate professor of physics. Their electrical properties are remarkably uniform. Perfect insulators, boron nitride nanotubes could be doped with other materials to form designer semiconductors that could be used in high-powered electronics.

Unfortunately, making nanotubes from boron and nitrogen has been easier said than done. They have always required special instrumentation, dangerous chemistry, or temperatures of over 1,500 degrees Celsius to assemble. Even at that, the products are shot through with impurities.

"We've been stuck for more than ten years because nobody could grow them well on substrates," says Yap. "But now we can."

Yap and his team have grown virtual Persian carpets of tiny, perfect fibers on a substrate made from simple catalysts, magnesium oxide, iron, or nickel. And they have managed it using the same instrumentation for growing carbon nanotubes, at about 1,100 degrees Celsius.

The boron nitride nanotubes can be made to assemble exclusively on these catalysts, so the researchers can control precisely where they grow. "You could write 'Michigan Tech' in nanotubes," says Yap.

These transparent nanotube sheets have another interesting property: they shed water like a duck's back, a quality known as the lotus effect. "Water just slides away," he says. "Anything coated with it would not only be stain resistant, it would be protected from anything water-soluble." This superhydrophobicity holds at all pH levels, so anything coated with it would be protected from even the strongest acids and alkalies.


History of greed, power, and the Golden Gate receives accolades

Historian Louise Nelson Dyble has received the Abel Wolman Award for her 2009 book on the world's most famous bridge. Presented by the Public Works Historical Society, it recognizes the best new work in public works history.

Paying the Toll: Local Power, Regional Politics, and the Golden Gate Bridge tells the tale of the Golden Gate Bridge from 1923, when it was a mere twinkle in the eyes of Northern California boosters, who hoped to lure tourists and their dollars north, and San Francisco leaders, who felt a link with Marin County would cement their city's position as the region's main metropolis.

Dyble then tracks the history of the Golden Gate Bridge and Highway District—a special agency formed only to finance and build the bridge. Although voters were originally promised that the bridge would be free once it was paid for, the bridge district didn't want to die. Instead, it fought for survival and won, despite a growing reputation for extravagance and corruption. For the toll-paying public, the district became a loathed symbol of government gone hideously wrong.

Paying the Toll is a cautionary tale for communities faced with financing a major public works project. To cash-strapped state and local governments, handing projects over to quasi-independent authorities can seem like an ideal solution. But yielding control often has a price down the road. "If the only focus is on building infrastructure and getting it financed quickly and cheaply, you can get in trouble," says Dyble. "You have to consider the long-term consequences of how you do it." The winners may not be who you think.


Using mining waste to grow an industry

Ralph Hodek with a handful of stamp sand, a copper-rich waste product of mining that brings fungicidal properties to roofing shingles.
Jonathan May photo

A project is under way to use the Keweenaw's stamp sand, a barren and unsightly leftover of the copper mining in the region, as the bedrock of an economic boon.

Aesthetically unattractive, the sands are a financial beauty—expansive, accessible, and ideal for making roofing shingles, which are the biggest part of the $9 billion roofing industry.

Shingles are 30 percent asphalt and 70 percent rock granules. Those rocky granules are expensive: Manufacturers have to mine the rock, crush it, and add copper to retard the growth of moss, lichen, fungus, and algae. Stamp sand has already been mined and crushed, and it contains the copper naturally.

"We can use material that we already have," says Ralph Hodek, an associate professor of civil and environmental engineering. "Recycling stamp sand is a very, very good thing. We're hoping not only to make a major financial impact for the area, but also to remove this unsightly material."

Hodek devised an additive and a process to better adhere the stamp sand to the asphalt. "It has to bind and hang on for twenty to thirty years," he says.

"We significantly improved the tenacity."

Michigan Tech alumnus Domenic Popko, of Big Traverse Bay, is the entrepreneur behind this enterprise. While at the Institute for Materials Processing, he began his inquiry into exploiting the antimicrobial properties of stamp sands.

In the short term, the team hopes to establish a local plant that could employ up to forty people supplying stamp sand to the roofing industry. Eventually, they would like to develop a facility for manufacturing shingles that would employ three hundred people.

One man's trash is another man's treasure? "That's what they say," says Popko. "We'll see."


Stressed-out poplars

People aren't the only things that suffer from stress. Trees deal with it too.

Too much or too little water can stress a tree, as can pollution, climate change, or scarcity of a nutrient.

Helping trees and crops adapt to stress is a key goal of plant biologists worldwide. Now research led by Victor Busov, associate professor in the School of Forest Resources and Environmental Science, has identified the molecular mechanism that Populus—common poplars, cottonwoods, and aspens—uses to adapt to changing soil conditions, as well as some of the genes that turn the process off or on. They hope to apply what they've learned to find ways to make them more stress-tolerant.

With colleagues at Michigan Tech, the University of Georgia, Oregon State University, and the Beijing Forestry University, Busov searched through thousands of genes in the Populus genome for the mechanism that regulates the plant's decision to grow tall or to spread out its roots to find what it needs.

The key players turned out to be a family of hormones called gibberellins, referred to as GAs.

The researchers found that GAs interact with other plant hormones to tell the plant whether to reach for the sky or build a bigger, better network of roots.

The scientists compared the root and stem growth of GA-deficient trees to others that contained moderate amounts of GAs and a control group of wild-type plants with normal GAs. They found that the more GAs, the more a plant's stem flourished, while its roots remained spindly. When production of GAs was shut down, the plants looked dwarfed, while their lateral roots grew luxuriant and full.

"Our hope is that by understanding how this works, we can manipulate the system so the plants can adapt faster and better to stressful conditions," Busov explains.

The researchers reported on their work in the March 2010 issue of The Plant Cell.


Bridges in trouble: diagnosing their ills from a distance

Tess Ahlborn leads a $2.8 million project to identify technologies that cna alert officials when bridges are in trouble.
Ryan Schumacher photo

Tess Ahlborn believes we could learn a lot from bridges, if only we could hear what they have to say. Now, she aims to find the best ways to listen in.

Ahlborn, a professor of civil and environmental engineering, leads a team of two dozen Michigan Tech researchers working to identify the best remote-sensing technologies for monitoring

the health of bridges. The goal of the $2.8 million project goes beyond preventing disasters like the one that befell Minneapolis's I-35W bridge in August 2007. "We hope this will help decision makers make informed choices about what bridge should be repaired next."

And there are so many choices. "Our bridges are in rotten condition," she says. "The US got a grade of C overall on the condition of its bridges, and Michigan got a whopping D."
The project is funded by $1.4 million from the US Department of Transportation's Research and Innovative Technology Administration, in-kind services from the Michigan Department of Transportation and the nonprofit Center for Automotive Research, and additional support from Michigan Tech. Researchers on the multidisciplinary project are drawn from the on-campus Michigan Tech Transportation Institute and the Michigan Tech Research Institute in Ann Arbor.

As with people, bridges start getting sick long before they develop obvious symptoms. "Lots of things are involved in a bridge's condition," says Ahlborn. Water can seep into minute fissures and form cracks as it freezes and thaws. Forces ranging from heavy traffic to tiny earthquakes can take their toll. And with on-site inspections occurring only once every two years, monitoring a bridge's condition has been a difficult challenge. But technologies developed in recent years could very well make the inspector's job easier.

"We can use remote sensing to do everything from diagnosing illnesses to finding wetlands," Ahlborn says. "We ought to be able to use it to find out what's wrong with bridges."

The aim of the research is not to develop new remote-sensing technologies, she stresses. "We want to identify existing technologies that show promise and are affordable."

In addition to monitoring and accessing bridge conditions, the technology must also make information easily available for those responsible for bridge maintenance and repair. "This isn't meant to eliminate bridge inspectors," Ahlborn stressed. "It should be a tool that allows them to do their jobs better."

For more information visit mtti.mtu.edu/bridgecondition.


Clean genes

Birds do it, bees do it. Even scientists in labs do it. But the scientists can't hold a candle to the birds and the bees, who can make gobs of primo DNA without even thinking about it.

DNA is a critical element of gene therapy, and scientists working to develop cures for diseases make it with synthesizers. Unfortunately, synthesizers don't do nearly as good a job as cells in stringing nucleic acids together to make DNA, and many of the resulting sequences—called truncated DNA—are too short and must be discarded.

Isolating perfect DNA sequences is so expensive that some clinical trials for gene therapy drugs have been put on hold for lack of funding. A discovery by Shiyue Fang, an associate professor of chemistry, could change that.

"Our method can provide high-quality, pure synthetic DNA by the kilogram at a much lower cost," he says. It could also be used to purify RNA and other biological molecules, such as peptides, that have potential as pharmaceuticals.

Fang adds monomers—molecules that can link together into polymers—to the nucleic acids in a stock DNA synthesizer. Truncated DNA won't attach to the monomers, but all other strands of DNA will. Then, once the synthesis is complete, the monomers join together to form a long polymer hanging with perfect DNA sequences, like clean laundry on a clothesline. "Then we just snip them off," says Fang. "It's a nice trick."

Fang's process does not weed out those few DNA sequences that are too long or are missing a nucleic acid. "Fortunately, these impurities exist only in minute quantities," he says.

Fang is now tweaking the process so that the monomers attach only to the truncated DNA. It's relatively easy to wash the polymers out of the solution, leaving behind the perfect strands.

Fang has filed a patent application on the process and hopes it can soon be put to good use by medical researchers. And, as DNA drugs enter the market, his purification method could drastically reduce manufacturing costs.

Fang's work has been funded by the National Science Foundation.


Book illuminates why aunts matter

Perhaps she let you do things Mom and Dad didn't. Maybe she made you work hard but paid you for your chores. There are myriad other examples of relationships most of us have had with aunts, and a new book explores their importance in our lives.

Humanities professor Patty Sotirin has authored Aunting: Cultural Practices that Sustain Family and Community Life, published by Baylor Press and coauthored by Laura Ellingson of Santa Clara University. The book uncovers many stories and some surprising nuances about our interactions with our aunts—those to whom we are related and those whom we choose.

Many of the strong connections with aunts exist because this role is more flexible than parenting, Sotirin says. And aunts don't have to be related, either, hence the new verb, "aunting," a set of practices that supports personal, familial, and community bonds through material, emotional, and symbolic means.

"Even a stepmom or a mentor at school can do aunting," says Sotirin. "Laura (Ellingson) and I realized early that aunting was a rich and complex topic."

Aunting involves emotional and socialization aspects that are both varied and flexible.

"We heard stories of aunts who indulged their nieces and nephews, aunts who were strict and demanding, and eccentric aunts," she says.

"Aunts can operate with different rules—outside but not necessarily contrary to—those in your house."

Also, aunts show both nephews and nieces that there are many life choices possible.

"Each aunt shows a different life path. One may be a career woman, another a stay-at-home mom," Sotirin says. "One aunt may seem like a great role model, another's situation may make a niece or nephew realize the consequences of certain choices."

Sotirin and Ellingson are already busy on their next project: aunts in popular culture. "Aunt Bee on Andy Griffith, Auntie Em in The Wizard of Oz, and Auntie Mame all take care of a nephew or niece, but they each do that very differently," Sotirin says. "These aunts may reaffirm family values and ideals, but they can also be seen as examples of more alternative, more eccentric families."


A research center for the Great Lakes

The new Great Lakes Research Center will provide a framework for studying a system containing 22 percent of the world's fresh water. Artist's rendering courtesy of FTC&H

The University broke ground in August for a facility that will embody a major component of Michigan Tech's research. A thriving program in water resources studies and education makes Tech a natural location for the Great Lakes Research Center.

The $25.3 million center on the campus waterfront will include aquatic laboratories, a hydraulics lab, coastal research instrumentation, boathouse facilities, offices, and conference rooms—all housing interdisciplinary research and education related to the Great Lakes.

It will also further a research and educational partnership between Michigan Tech and the US Army Corps of Engineers' Research and Development Center Environmental Laboratory, in Vicksburg, Mississippi, the corps's water resources research facility. Michigan Tech and the Corps of Engineers will conduct cross-disciplinary research and education focusing on protection and restoration of the Great Lakes. Vicksburg scientists will work collaboratively with Michigan Tech researchers and students in both locations.

The state is paying 74 percent of the cost. Michigan Tech's share is 26 percent, approximately $6.6 million.

Construction is expected to be completed in spring 2012.


Humanities, arts in NSF's Top 100

Michigan Tech is accustomed to high rankings from the National Science Foundation when it comes to research expenditures in engineering and science. But, lately, some nonengineering fields have been getting noticed.

The Visual and Performing Arts and Humanities have both finished within the top 100 on NSF's 2008 research expenditure rankings, released in 2010. Among all universities, Visual and Performing Arts ranked fifty-ninth, while Humanities was eighty-seventh. Michigan Tech was ranked sixty-sixth among universities without medical schools.

So, why now, and why is this important?

David Reed, vice president for research, says that NSF now includes these disciplines in their annual survey of academic activities—in the past they didn't—and Tech's strength in these areas is reflected in the results.

"Michigan Tech's heritage of innovation in science and engineering is well known, but we have equally strong scholarly and creative programs in Visual and Performing Arts and in Humanities, which are sometimes not given the recognition they deserve," Reed says.

"Generations of Tech students have found these programs to be essential in their education and critical to their experience at Tech," he says. "These survey results show that the scholarly contributions of faculty, staff, and students in these areas are equally strong."

Roger Held, chair of the visual and performing arts department, agrees.

"It's also a measure of the University's commitment to the arts," he says. "And, it's a validation of our approach to integrating arts and technology—part and parcel of the twenty-first century's fluid development of new media."

A number of faculty have received external funding, including Michael Bowler, a professor of philosophy in the humanities department.

Bowler is principal investigator on a $500,000 NSF grant that involves faculty from a number of departments. "We are eager to engage in interdisciplinary research with others across campus, and the humanities department has much to contribute in this respect," Bowler said.


A sensor that knows you're sick

Craig Friedrich
Adam Johnson Photo

Your body undergoes a cascade of telltale chemical changes when you're sick. What if doctors could identify those changes from a drop of saliva and find out what might be wrong?

Such is the aim of a new partnership between Michigan Tech and Marshall University called the Center for Diagnostic Nanosystems. It is the brainchild of Craig Friedrich, director of graduate studies for the Department of Mechanical Engineering–Engineering Mechanics and holder of the Robbins Chair in Sustainable Design and Manufacturing, and Eric Blough, a Michigan Tech alumnus and an associate professor of biological sciences at Marshall University, in Huntington, West Virginia.

With $1.9 million in federal funding, they are combining Tech's strengths in nanotechnology and engineering with Marshall's expertise in medicine and biotechnology. Together, they are cooking up new microdevices that could help transform medical diagnostics.

"Human physiology is based on biochemical processes that leave a signature behind," Friedrich explains. "With nanosensing technology, we can detect a single molecule. The challenge is to know which molecule or molecules will tell the correct story."

Friedrich's group in the Multi-Scale Technologies Institute is building these nanosensors with nanowires twenty nanometers across and a micron long, etched into silicon chips. To each wire, they will attach a small molecule that will react in the presence of a specific biochemical associated with a given malady. And that reaction will change the conductivity of the nanowire, signaling the presence of the molecule—and potentially the disease.

The sensors could be used on body fluids, even saliva, depending on the target chemical. "We want to further develop a spit sensor," says Friedrich.

Marshall University will provide the medical and biochemical research on the project, while the Michigan Tech team will develop the nanowire sensing chip and related hardware.

The partnership holds promise for improving medical diagnostics and in advancing nanotechnology. Plus, says Friedrich, the science is fascinating. "We think it's going to be a lot of fun."

See Friedrich’s lecture on bio-nano hybrid materials under “Research” on Tech’s iTunes U site, accessible here: mtu.edu/ets/techonline/itunesu