Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > Researchers create first nanofluidic transistor

Abstract:
UC Berkeley, LBNL researchers shuttle ions through nanochannels to produce first nanofluidic transistor

Researchers create first nanofluidic transistor

Berkeley, CA | June 28, 2005

University of California, Berkeley, researchers have invented a variation on the standard electronic transistor, creating the first "nanofluidic" transistor that allows them to control the movement of ions through sub-microscopic, water-filled channels.

The researchers - a chemist and a mechanical engineer - predict that, just as the electronic transistor became the main component of microprocessors and integrated circuits, so will nanofluidic transistors anchor molecular processors, allowing microscopic chemical plants on a chip that operate without moving parts. No valves to get stuck, no pumps to blow, no mixers to get clogged.

"A transistor is like a valve, but you use electricity to open or close it," explained Arun Majumdar, professor of mechanical engineering at UC Berkeley. "Here, we use a voltage to open or close an ion channel. Now that we've shown you can make this building block, we can hook it up to an electronic chip to control the fluidics."

One application Majumdar and colleague Peidong Yang, UC Berkeley professor of chemistry, are exploring is cancer diagnosis. A nanoscale chemical analysis chip could, theoretically, take the contents of as few as 10 cancer cells and pull out protein markers that can tip doctors to the best means of attacking the cancer.

"This is an ideal way to open up cells and identify the proteins or enzymes inside," he said. "An enzyme profile would tell doctors a lot about the kind of cancer, especially in its early stages when there are only a few cells around."

Yang, who built a variation of the transistor using nanotubes, is equally intrigued by the computational possibilities of the device.

"It may sound a little bit far fetched, but we're thinking about whether we can do the same thing with nanofluidic transistors as we can currently with MOSFETs," he said, referring to the Metal-Oxide Semiconductor Field Effect Transistors used in most of today's microprocessor chips. "Using molecules to process information gives you a fundamentally different information processing device."

Majumdar, Yang and colleagues Rohit Karnik, a mechanical engineering graduate student; Rong Fan, a chemistry graduate student; and mechanical engineering students Min Yue and Deyu Li reported their success - the product of three years of effort - in the May issue of the journal Nanoletters. Yang and Majumdar are also faculty scientists at Lawrence Berkeley National Laboratory.

One big advantage of nanofluidic transistors, Majumdar said, is that they could be made using the same manufacturing technology that today produces integrated circuits. Nanofluidic channels could be integrated with electronics on a single silicon chip, with the electronics controlling the operation of the nanofluidics. The only microscale parts of the device are the microchannels for injecting liquid.

Majumdar and Yang's team constructed a 35-nanometer-high channel between two silicon dioxide plates, then filled the channel with water and potassium chloride salt. They showed that by applying a voltage across the channel by means of electrodes attached to the plates, they could shut off the flow of potassium ions through the water. This is analogous to the control of electron flow through a transistor by means of a gate voltage.

Such ion manipulations are not possible through microscopic channels because ions in the liquid quickly move to the plates and cancel out the voltage, basically shielding the interior of the liquid from the electric field. Channels less than 100 nanometers across, however, are so small that this shielding doesn't occur, so ions in the bulk liquid can be pushed or pulled by electric voltages.

If the ions are proteins, they can be shuttled through channels lined with fluorescent antibodies for detecting or sensing. If the ions are pieces of DNA, they can be sorted and sequenced. In fact, the authors say, any highly sensitive biomolecular sensing down to the level of a single molecule could be performed with nanofluidic transistors. They demonstrated that labeled, charged DNA fragments could be manipulated in their transistor.

Yang, who is adept at making nanoscale lasers, tubes, wires and other devices, created a version of the transistor using nanotubes with internal diameters of 20 nanometers, proving that the same sort of molecular processing can be done with these innovative structures. While Majumdar foresees putting electronic and nanofluidic transistors on the same chip to provide computer control of chemical processing, Yang foresees the computing and chemical processing being done by the same nanofluidic channels.

"With nanotubes, you have access to much smaller dimensions compared to conventional nanofabrication, but in terms of integration, it's more difficult," Yang said. "For the future, both processes are fundamentally interesting, and eventually devices will combine both."

Majumdar and Yang acknowledge that a lot more work needs to be done, including understanding the surface effects inside nanochannels. In addition, the voltage required to shut off ion flow is now 75 volts, far too high for any of today's integrated circuits. But their team has a few other papers waiting to appear in Nanoletters and in the Physical Review Letters that push the technology farther than this initial paper. They hope to beat the time lag between invention of the transistor in 1947 and creation of the first integrated circuit in 1960.

"We want to be the first to build integrated circuits with just three transistors able to do sorting and eluting, just as a two- or three-bit processor can do multiplexing and addressing," Majumdar said.

The work was supported by the National Cancer Institute's Innovative Molecular Analysis Technologies program and by the Department of Energy. Current work is being funded by the National Science Foundation.

####


Note: Arun Majumdar can be reached at (510) 643-8199 or majumdar@me.berkeley.edu. Peidong Yang is at (510) 643-1545 or p_yang@berkeley.edu

Contact:
Robert Sanders
(510) 643-6998
rsanders@berkeley.edu

Copyright © University of California, Berkeley

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Nanotubes/Buckyballs

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Beyond LEDs: Brighter, new energy-saving flat panel lights based on carbon nanotubes - Planar light source using a phosphor screen with highly crystalline single-walled carbon nanotubes (SWCNTs) as field emitters demonstrates its potential for energy-efficient lighting device October 14th, 2014

Nanomedicine

RF Heating of Magnetic Nanoparticles Improves the Thawing of Cryopreserved Biomaterials October 23rd, 2014

Bipolar Disorder Discovery at the Nano Level: Tiny structures found in brain synapses help scientists better understand disorder October 22nd, 2014

Journal Nanotechnology Progress International (JONPI), 2014, Volume 5, Issue 1, pp 1-24 October 22nd, 2014

TARA Biosystems and Harris & Harris Group Form Company to Improve Safety and Efficacy of New Therapies October 22nd, 2014

Nanoelectronics

NIST offers electronics industry 2 ways to snoop on self-organizing molecules October 22nd, 2014

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Announcements

SUNY Polytechnic Institute Invites the Public to Attend its Popular Statewide 'NANOvember' Series of Outreach and Educational Events October 23rd, 2014

Advancing thin film research with nanostructured AZO: Innovnano’s unique and cost-effective AZO sputtering targets for the production of transparent conducting oxides October 23rd, 2014

Strengthening thin-film bonds with ultrafast data collection October 23rd, 2014

RF Heating of Magnetic Nanoparticles Improves the Thawing of Cryopreserved Biomaterials October 23rd, 2014

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More














ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE