Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New nanoscale electrical phenomenon discovered

19.05.2010
At the scale of the very small, physics can get peculiar. A University of Michigan biomedical engineering professor has discovered a new instance of such a nanoscale phenomenon—one that could lead to faster, less expensive portable diagnostic devices and push back frontiers in building micro-mechanical and "lab on a chip" devices.

In our macroscale world, materials called conductors effectively transmit electricity and materials called insulators or dielectrics don't, unless they are jolted with an extremely high voltage. Under such "dielectric breakdown" circumstances, as when a bolt of lightening hits a rooftop, the dielectric (the rooftop in this example) suffers irreversible damage.

This isn't the case at the nanoscale, according to a new discovery by Alan Hunt, an associate professor in the Department of Biomedical Engineering. Hunt and his research team were able to get an electric current to pass nondestructively through a sliver of glass, which isn't usually a conductor.

A paper on the research is newly published online in Nature Nanotechnology.

"This is a new, truly nanoscale physical phenomenon," Hunt said. "At larger scales, it doesn't work. You get extreme heating and damage.

"What matters is how steep the voltage drop is across the distance of the dielectric. When you get down to the nanoscale and you make your dielectric exceedingly thin, you can achieve the breakdown with modest voltages that batteries can provide. You don't get the damage because you're at such a small scale that heat dissipates extraordinarily quickly."

These conducting nanoscale dielectric slivers are what Hunt calls liquid glass electrodes, fabricated at the U-M Center for Ultrafast Optical Science with a femtosecond laser, which emits light pulses that are only quadrillionths of a second long.

The glass electrodes are ideal for use in lab-on-a-chip devices that integrate multiple laboratory functions onto one chip just millimeters or centimeters in size. The devices could lead to instant home tests for illnesses, food contaminants and toxic gases. But most of them need a power source to operate, and right now they rely on wires to route this power. It's often difficult for engineers to insert these wires into the tiny machines, Hunt said.

"The design of microfluidic devices is constrained because of the power problem," Hunt said. "But we can machine electrodes right into the device."

Instead of using wires to route electricity, Hunt's team etches channels through which ionic fluid can transmit electricity. These channels, 10 thousand times thinner than the dot of this "i," physically dead-end at their intersections with the microfluidic or nanofluidic channels in which analysis is being conducted on the lab-on a-chip (this is important to avoid contamination). But the electricity in the ionic channels can zip through the thin glass dead-end without harming the device in the process.

This discovery is the result of an accident. Two channels in an experimental nanofluidic device didn't line up properly, Hunt said, but the researchers found that electricity did pass through the device.

"We were surprised by this, as it runs counter to accepted thinking about the behavior of nonconductive materials," Hunt said. "Upon further study we were able to understand why this could happen, but only at the nanometer scale."

As for electronics applications, Hunt said that the wiring necessary in integrated circuits fundamentally limits their size.

"If you could utilize reversible dielectric breakdown to work for you instead of against you, that might significantly change things," Hunt said.

The paper is called "Liquid glass electrodes for nanofluidics." This research is funded by the National Institutes of Health.

The university is pursuing patent protection for the intellectual property, and is seeking commercialization partners to help bring the technology to market.

The University of Michigan College of Engineering is ranked among the top engineering schools in the country. At $160 million annually, its engineering research budget is one of the largest of any public university. Michigan Engineering is home to 11 academic departments and a National Science Foundation Engineering Research Center. The college plays a leading role in the Michigan Memorial Phoenix Energy Institute and hosts the world-class Lurie Nanofabrication Facility. Michigan Engineering's premier scholarship, international scale and multidisciplinary scope combine to create The Michigan Difference. Find out more at www.engin.umich.edu.

Contact: Nicole Casal Moore
Phone: (734) 647-7087

Nicole Casal Moore | EurekAlert!
Further information:
http://www.umich.edu

Further reports about: Ferchau Engineering Science TV microfluidic device toxic gas

More articles from Physics and Astronomy:

nachricht Long-lived storage of a photonic qubit for worldwide teleportation
12.12.2017 | Max-Planck-Institut für Quantenoptik

nachricht Telescopes team up to study giant galaxy
12.12.2017 | International Centre for Radio Astronomy Research

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

Im Focus: Successful Mechanical Testing of Nanowires

With innovative experiments, researchers at the Helmholtz-Zentrums Geesthacht and the Technical University Hamburg unravel why tiny metallic structures are extremely strong

Light-weight and simultaneously strong – porous metallic nanomaterials promise interesting applications as, for instance, for future aeroplanes with enhanced...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Long-lived storage of a photonic qubit for worldwide teleportation

12.12.2017 | Physics and Astronomy

Multi-year submarine-canyon study challenges textbook theories about turbidity currents

12.12.2017 | Earth Sciences

Electromagnetic water cloak eliminates drag and wake

12.12.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>