A team of researchers from the University of Notre Dame and Purdue University has received a three-year grant of $500,000 from the U.S. Department of Agriculture to develop a new technology that can rapidly test milk and other dairy products for harmful pathogens.

Though the research will be applicable to many microorganisms, the team’s first goal is to reduce the incidence of brucellosis, a condition caused by infection from Brucella bacteria, various strains of which are found in sheep, goats, cattle and swine. Brucellosis is the most common animal-to-human infection worldwide, with more than 500,000 new cases reported each year. It rarely causes death, but it can result in prolonged health problems.

“The infection is usually acquired by ingestion of contaminated animal products, typically raw milk and other unpasteurized dairy products such as soft cheeses,” says Ramesh Vemulapalli, professor of veterinary immunology and microbiology at Purdue and a collaborating investigator on the project.

“Although it is rarely seen in developed countries, there is growing concern that these pathogens are spreading because of increased global tourism and immigration.”

The researchers are using the USDA funding to design and build a portable device that can analyze a food sample and provide a reading within 15 minutes.

The technology is based on a microfluidic detection platform developed in the of project leader , Bayer Professor of at Notre Dame and an investigator in the University’s .

“Our system is very sensitive and selective,” explains Chang. “We can take a sample, concentrate the microorganisms in it and then detect fewer than a hundred bacteria per milliliter.”

One major technical challenge is pretreating the milk before it hits the instrument’s sensors.

“There are many solids and large molecules, such as fat, in milk,” says co-investigator Arun Bhunia, professor of food science at Purdue. “We are working on a way to incorporate a quick and seamless pretreatment phase into the system.”

Team members are also focused on usability and design, because they want the device to be functional for people without high levels of technical training.

Advanced Diagnostics and Therapeutics — a component of Notre Dame’s initiative — is dedicated to developing tools and technologies to combat disease, promote health and safeguard the environment.

Contact: Chia Chang, 574-631-5697, hchang@nd.edu

Researchers at the University of Notre Dame and Pennsylvania State University have announced breakthroughs in the development of tunneling field-effect transistors (TFETs), a semiconductor technology that takes advantage of the quirky behavior of electrons at the quantum level.

Transistors are the building blocks of the electronic devices that power the digital world, and much of the growth in computing power over the past 40 years has been made possible by increases in the number of transistors that can be packed onto silicon chips.

But that growth, if left to current technology, may soon be coming to an end.

Many in the semiconductor field think the industry is fast approaching the physical limits of transistor miniaturization. The major problem in modern transistors is power leakage leading to the generation of excessive heat from billions of transistors in close proximity.

The recent advances at Notre Dame and Penn State — who are partners in the (MIND) — show that TFETs are on track to solve these problems by delivering comparable performance to today’s transistors, but with much greater energy efficiency.

They do this by taking advantage of the ability of electrons to “tunnel” through solids, an effect that would seem like magic at the human scale but is normal behavior at the quantum level.

“A transistor today acts much like a dam with a moveable gate” says , professor of electrical engineering at Notre Dame and the Frank M. Freimann Director of MIND. “The rate at which water flows, the current, depends on the height of the gate.

“With tunnel transistors, we have a new kind of gate, a gate that the current can flow through instead of over. We adjust the thickness of the gate electrically to turn the current on and off.

“Electron tunneling devices have a long history of commercialization,” adds Seabaugh. “You very likely have held more than a billion of these devices in a USB flash drive. The principle of quantum mechanical tunneling is already used for data storage devices.”

While TFETs don’t yet have the energy efficiency of current transistors, papers released in December 2011 by Penn State and March 2012 by Notre Dame demonstrate record improvements in tunnel transistor drive current, and more advances are expected in the coming year.

“Our developments are based on finding the right combination of semiconductor materials with which to build these devices,” says Suman Datta, professor of electrical engineering at Penn State.

“If we’re successful, the impact will be significant in terms of low-power integrated circuits. These, in turn, raise the possibility of self-powered circuits which, in conjunction with energy-harvesting devices, could enable active health monitoring, ambient intelligence and implantable medical devices.”

Another benefit of tunneling transistors is that using them to replace existing technology wouldn’t require a wholesale change in the semiconductor industry. Much of the existing circuit design and manufacturing infrastructure would remain the same.

“Strong university research on novel devices such as TFETs is critical for continuing the rapid pace of technology development,” said Jeff Welser, director of the . “Much of the industry recognizes that it will take collaborations with both academia and government agencies to find and develop these new concepts.”

Two other partners in the MIND center — Purdue University and The University of Texas at Dallas — have made significant contributions to the development of TFETs through the development of key modeling and analytical tools.

MIND is one of four centers funded by the Semiconductor Research Corporation’s Nanoelectronics Research Initiative (NRI). The goal of NRI and its university-based centers is to demonstrate novel computing devices capable of replacing the complementary metal oxide semiconductor transistor as a logic switch. Established in 2008, MIND is led by Notre Dame and includes Penn State, Purdue and University of Texas-Dallas.

Contacts: Alan Seabaugh, 574-631-4473, Alan.C.Seabaugh.1@nd.edu; Suman Datta, 814-865-0519, sdatta@engr.psu.edu

Reflecting its worldwide leadership in the search for new computing technologies, the University of Notre Dame has received two of 12 prestigious grants for cutting-edge nanoelectronics research that were awarded recently by the Semiconductor Research Corporation’s Nanoelectronics Research Initiative (SRC-NRI) and the National Science Foundation.

“Universities were only allowed to submit two proposals each to the program,” says , McCloskey Dean of the . “The fact that both of Notre Dame’s proposals were funded is a sign of the high quality and competitiveness nationally of our research in this critical field.”

According to the program solicitation, the aim of the joint 12-grant program, which totals $20 million over four years, is to support the search for new technologies that can replace today’s transistors. They build on previous research fostered by the SRC-NRI, which represents global computer chip manufacturers IBM, Intel, Texas Instruments, GLOBALFOUNDRIES and Micron Technology.

The two funded teams at Notre Dame—led by , Frank M. Freimann Professor of Electrical and Computer Engineering and director of the (NDnano); and , Frank M. Freimann Professor of Engineering—are truly multidisciplinary, bringing together electrical engineers, chemists, physicists, computer scientists and biologists to tackle problems of immense complexity.

Porod and co-investigators , , , and Gyorgy Csaba, received $1.8 million ($1.6 million from the NSF and $200,000 from the SRC-NRI) to explore a radical new approach to computational “thinking”—an approach based not on the familiar binary logic of 1s and 0s, but on physics-inspired and brain-like wave activity. The research envisions a future in which computer chips contain millions of cores, and processing elements in networks model the brain’s biological structure.

“This work will not merely lead to incremental improvements in information processing systems,” says Porod, “but will open the door to an entirely new approach to computing and computer architecture.”

Lent, along with colleagues , , and , were awarded $1.75 million ($1.55 million from NSF and $200,000 from SRC-NRI) to advance a similarly unconventional type of computing known as Quantum-dot Cellular Automata (QCA), which was pioneered at Notre Dame. In QCA, the familiar switches of current silicon-based transistors are replaced by single molecules that interact with neighboring molecules through changes in charge.

“Such molecular level computing has the potential to generate ultra-small devices that use very little power,” says Lent. “Generating heat has been the limiting factor in making computer circuits smaller and smaller. In this collaborative effort between Engineering and Chemistry our aim is to design and build molecules specifically suited to the task.”

Notre Dame has been focused on nanoelectronics research since the 1980s and is the lead institution in the SRC-NRI-funded (MIND), which is part of a network of 24 universities conducting nanotechnology research around the United States.

“The search for a new semiconductor device that will provide the U.S. with a leadership position in the global era of nanoelectronics relies on making discoveries at these kinds of advanced universities,” said Jeff Welser, director of the Nanoelectronics Research Initiative for SRC. “These schools have the talent and capabilities needed to produce critical research that helps to raise both our national competitiveness and economic progress.”

Contact: Wolfgang Porod, 574-631-6376, porod@nd.edu; Craig Lent, 574-631-6992, lent@nd.edu

The behavior of fluids seems simple and intuitive—rivers flow downhill, drinks take the shape of the glass they’re in, etc.

But at extremely small scales, fluids follow a physics that can seem strange to us. The effects of gravity and inertia, for example, give way to more powerful forces like surface tension and viscosity. By understanding and exploiting these properties, engineers in the young field of “microfluidics” have developed a wide range of useful applications, including well-known ones in the home (inkjet printers) and on police dramas (DNA analyzers).

For , Bayer Professor of Chemical and Biomolecular Engineering at the University of Notre Dame, the greatest uses of microfluidic technology still lie ahead, in applications that will help tackle some of the world’s toughest health and environmental problems.

Chang’s vision is of easy-to-operate, handheld devices that can rapidly detect such things as pathogens in blood, toxins in food and water, and even track invasive species as they threaten crops and ecosystems. It is a vision in which the power of a modern research lab is concentrated into a smartphone-sized tool that can be used to diagnose disease as easily in a remote village as it can in a city hospital.

And it is a vision informed by a life journey that stretches from Southeast Asia to South Bend.

Chang was born in Taiwan, but moved several times as the family followed the career path of his father, a biochemist.

“Upon arriving in Singapore,” recounts Chang, “we found that our new home was without electricity or running water. We were relatively well off and I do not remember life being particularly hard, but we had an outhouse in the yard. Bathing for me was going to the water pump in the yard and dousing myself there. Nights were spent listening to a transistor radio around a kerosene lamp, and going to school meant squeezing into a taxi with about 10 other kids. This lasted 3 years until we went to Malaysia.”

Chang started high school in Kuala Lumpur, but as a Chinese foreigner he was prevented by Malaysian policies at the time from becoming a citizen or attending college.

His prospects changed when he met Sam and Dodo Standring, math and science teachers from California. They were amazed by the young man’s sense of humor, athletic ability, and intelligence, particularly his facility with chemistry. By promising to serve as his guardians they convinced Chang’s parents to let him come back to the U.S. for his senior year of high school.

As a student (and new English speaker) at Troy High 91��Ƶ in Fullerton, Calif., Chang won a number of academic awards. In one case, he collaborated with a Cal State professor on a project that highlighted his math abilities, and this brought him to the attention of the California Institute of Technology. Caltech offered him a work-study scholarship, and he supported himself by working 10 to 20 hours a week as both a computer programmer and food service employee, and by handling odd jobs.

Despite these challenges, Dodo Standring says that it was his work ethic, instilled in him by his mother, that enabled Chang to graduate from Caltech and earn a Ph.D at Princeton by the time he was 24.

After several teaching stints around the U.S., Chang and his wife, Mei-Chi Shaw, a professor of mathematics, both found a home at Notre Dame.

Here, he expanded his research, served as chair of the department, developed several patents on microfluidic processes, wrote a definitive textbook on the field, started a leading journal, and founded the .

One of the overarching goals throughout his career has been to forge multidisciplinary collaborations focused on the biomedical applications of microfluidics.

He explains, “My scientific contribution is from the transport angle—how to concentrate and sort molecules and detect them on small devices. These are engineering challenges involving a lot of transport and flow physics, which I specialize in. They are also the key scientific issues in designing biosensors and diagnostics for in-field applications.”

More recently, Chang has become a principal investigator in Notre Dame’s new (AD&T) initiative, which is a broader program, spanning both science and engineering, to develop powerful and portable technologies for medical and environmental health.

“Chia Chang’s research goals are a great example of what Advanced Diagnostics and Therapeutics is all about” says , Arthur J. Schmitt Professor of Chemical and Biomolecular Engineering and director of the initiative. “Our purpose is to take discoveries in the lab that have great potential and, with partners from inside and outside of the University, test them, turn them into usable tools, and get those tools out into the world where they can do some real good. It’s very entrepreneurial.”

Chang adds, “The entrepreneurial spirit of AD&T is very attractive to me, as is the fact that outside companies are starting to license and develop my technologies. In this regard, the proximity of Notre Dame’s is also important.”

As one of the University’s recent , AD&T is part of Notre Dame’s commitment to serving society as a preeminent research university, and that is also part of the appeal to Chang.

“We still have a lot of growing to do, particularly in research,” he says, “and I feel I can contribute to this and make a bigger impact [at Notre Dame] than at other places.”

Though he’s mindful of where he’s come from, it is this focus on the future that continues to excite Chang. “My goal is that more diagnostic technologies, from my lab and others, be developed—technologies that can make a lasting impact on global health.”