Featured Research

from universities, journals, and other organizations

Laser, electric fields combined for new 'lab-on-chip' technologies

Date:
July 5, 2011
Source:
Purdue University
Summary:
Researchers are developing new technologies that combine a laser and electric fields to manipulate fluids and tiny particles such as bacteria, viruses and DNA for a range of potential applications, from drug manufacturing to food safety.

This graphic illustrates a new technology that combines a laser and electric fields to manipulate fluids and tiny particles such as bacteria, viruses and DNA for a range of potential applications from drug manufacturing to food safety. The technologies could bring innovative sensors and analytical devices for "lab-on-a-chip" applications.
Credit: Stuart J. Williams, University of Louisville

Researchers are developing new technologies that combine a laser and electric fields to manipulate fluids and tiny particles such as bacteria, viruses and DNA for a range of potential applications, from drug manufacturing to food safety.

The technologies could bring innovative sensors and analytical devices for "lab-on-a-chip" applications, or miniature instruments that perform measurements normally requiring large laboratory equipment, said Steven T. Wereley, a Purdue University professor of mechanical engineering.

The method, called "hybrid optoelectric manipulation in microfluidics," is a potential new tool for applications including medical diagnostics, testing food and water, crime-scene forensics, and pharmaceutical manufacturing.

"This is a cutting-edge technology that has developed over the last decade from research at a handful of universities," said Aloke Kumar, a Wigner Fellow and staff member at Oak Ridge National Laboratory.

He is lead author of an article about the technology featured on the cover of the July 7 issue of Lab on a Chip magazine, published by the Royal Society of Chemistry.

The article is written by Wereley; Kumar; Stuart J. Williams, an assistant professor of mechanical engineering at the University of Louisville; Han-Sheng Chuang, an assistant professor in the Department of Biomedical Engineering at National Cheng Kung University; and Nicolas G. Green, a researcher at the University of Southampton.

"A very important aspect is that we have achieved an integration of technologies that enables manipulation across a very wide length scale spectrum," Kumar said. "This enables us to manipulate not only big-sized objects like droplets but also tiny DNA molecules inside droplets by using one combined technique. This can greatly enhance efficiency of lab-on-a-chip sensors."

Kumar, Williams and Chuang are past Purdue doctoral students who worked with Wereley. Much of the research has been based at the Birck Nanotechnology Center at Purdue's Discovery Park.

The technologies are ready for some applications, including medical diagnostics and environmental samples, Williams said.

"There are two main thrusts in applications," he said. "The first is micro- and nanomanufacturing and the second is lab-on-a-chip sensors. The latter has demonstrated biologically relevant applications in the past couple of years, and its expansion in this field is immediate and ongoing."

The technology works by first using a red laser to position a droplet on a platform specially fabricated at Purdue. Next, a highly focused infrared laser is used to heat the droplets, and then electric fields cause the heated liquid to circulate in a "microfluidic vortex." This vortex is used to isolate specific types of particles in the circulating liquid, like a micro centrifuge. Particle concentrations replicate the size, location and shape of the infrared laser pattern.

"This works very fast," Wereley said. "It takes less than a second for particles to respond and get pulled out of solution."

Systems using the hybrid optoelectric approach can be designed to precisely detect, manipulate and screen certain types of bacteria, including particular strains that render heavy metals less toxic.

"We are shooting for biological applications, such as groundwater remediation," Wereley said. "Even within the same strain of bacteria some are good at the task and some are not, and this technology makes it possible to efficiently cull those bacteria from others. The bacteria could be injected into the contaminated ground. You seed the ground with the bacteria, but first you need to find an economical way to separate it."

Purdue researchers also are pursuing the technology for pharmaceutical manufacturing, he said.

"These types of technology are good at being very dynamic, which means you can decide in real time to grab all particles of one size or one type and put them somewhere," Wereley said. "This is important for the field of pharmacy because a number of drugs are manufactured from solid particles suspended in liquid. The particles have to be collected and separated from the liquid."

This process is now done using filters and centrifuges.

"A centrifuge does the same sort of thing but it's global, it creates a force on every particle, whereas this new technology can specifically isolate only certain particles," Wereley said. "We can, say, collect all the particles that are one micron in diameter or get rid of anything bigger than two microns, so you can dynamically select which particles you want to keep."

The technology also may be used as a tool for nanomanufacturing because it shows promise for the assembly of suspended particles, called colloids. The ability to construct objects with colloids makes it possible to create structures with particular mechanical and thermal characteristics to manufacture electronic devices and tiny mechanical parts. The nanomanufacturing applications are at least five years away, he said.

The technology also can be used to learn fundamental electrokinetic forces of molecules and biological structures, which is difficult to do with existing technologies.

"Thus there are very fundamental science applications of these technologies as well," Kumar said.


Story Source:

The above story is based on materials provided by Purdue University. The original article was written by Emil Venere. Note: Materials may be edited for content and length.


Journal Reference:

  1. Aloke Kumar, Stuart J. Williams, Han-Sheng Chuang, Nicolas G. Green, Steven T. Wereley. Hybrid opto-electric manipulation in microfluidics—opportunities and challenges. Lab on a Chip, 2011; 11 (13): 2135 DOI: 10.1039/C1LC20208A

Cite This Page:

Purdue University. "Laser, electric fields combined for new 'lab-on-chip' technologies." ScienceDaily. ScienceDaily, 5 July 2011. <www.sciencedaily.com/releases/2011/07/110705123629.htm>.
Purdue University. (2011, July 5). Laser, electric fields combined for new 'lab-on-chip' technologies. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2011/07/110705123629.htm
Purdue University. "Laser, electric fields combined for new 'lab-on-chip' technologies." ScienceDaily. www.sciencedaily.com/releases/2011/07/110705123629.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins