Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New method manipulates particles for sensors, crime scene testing

08.06.2010
Researchers at Purdue University have developed a potential new tool for medical diagnostics, testing food and water for contamination, and crime-scene forensics.

The technique uses a combination of light and electric fields to position droplets and tiny particles, such as bacteria, viruses and DNA, which are contained inside the drops.

Other methods using either light or electric fields separately are able to position droplets or the particles they contain, but the new "hybrid optoelectric" device is able to do both, making it potentially practical for sensors and industrial processes, said mechanical engineering doctoral student Aloke Kumar.

Ordinarily, the particles inside droplets are detected when they randomly fall on a sensor's surface. However, the new method could improve sensor efficiency by actively moving particles to specific regions on an electronic chip for detection or analysis.

"This new hybrid technique is universal in the sense that we can manipulate a range of droplet and particle sizes, going all the way from microliter drops to particles a few nanometers long," said Steven T. Wereley, a professor of mechanical engineering who is working with Kumar.

The method offers promise for future "lab-on-a-chip" technology, using electronic chips to analyze biological samples for medical and environmental applications. Sensors based on the technique could make possible a new class of chemical analyses, or assays, with point-of-care devices in a doctor's office or hospitals.

Such sensors might be used to quickly analyze blood, urine and other bodily fluids for a range of applications, including drug screening; paternity testing; detecting coronary artery disease, tumors and various inherited diseases including cystic fibrosis; and detecting infectious diseases and bacteria, viruses and fungi that are difficult to culture using conventional laboratory methods.

"This technique also would be good for DNA tests, such as those used on the TV program 'CSI,' to identify crime suspects using only a small blood sample," Wereley said. "The idea is to use a chip to quickly carry out laboratory procedures called polymerase chain reaction and capillary electrophoresis. The new technology also should be good for testing food and water for pathogens such as E. coli or salmonella."

Critical to the technology are electrodes made of indium tin oxide, a transparent and electrically conductive material commonly used in consumer electronics for touch-screen displays. Liquid drops are positioned on the electrodes, and the infrared laser heats up both the electrodes and the droplets. Then electric fields in the electrodes cause the heated liquid to produce a "microfluidic vortex" of circulating liquid. This vortex enables researchers to position the particles in the circulating liquid by moving the infrared laser. The particles accumulate only where the laser is shined.

"Sensors are one of the immediate applications of this technology," said Kumar, who may continue the work as a postdoctoral researcher at the Oak Ridge National Laboratories, where he will complete a two-year Eugene Wigner Fellowship starting this month. "We should be able to improve the efficiency of sensors at least 10 times."

Findings were detailed in a research paper appearing June 1 in the journal Langmuir. The paper was written by Kumar, Wereley and former Purdue doctoral student Han-Sheng Chuang, now a postdoctoral researcher at the University of Pennsylvania. The research is based at the Birck Nanotechnology Center at Purdue's Discovery Park.

Purdue has filed a U.S. patent application on the design.

The technique might be used to manufacture sensors and other devices by modifying a phenomenon called the coffee-ring effect, which causes residue to form when liquid evaporates. Because the particles in the residue form only where the infrared laser shines, the procedure might be used to precisely position particles to create structures and circuits for biosensors and electronics.

"We have successfully used this technique to create spatially controlled microassemblies, and we hope that this would interest other research groups looking into the coffee-ring effect," Kumar said.

The work has been supported with funding from the National Science Foundation and the Micro/Nano Fluidics Fundamentals Focus (MF3) Center at the University of California, Irvine.

Emil Venere | EurekAlert!
Further information:
http://www.purdue.edu
http://www.purdue.edu/newsroom/research/2010/100607WereleyHybrid.html

Further reports about: Biosensors DNA Sensors coffee-ring effect electric field manufacture sensors

More articles from Power and Electrical Engineering:

nachricht Electron sandwich doubles thermoelectric performance
20.06.2018 | Hokkaido University

nachricht Agrophotovoltaics Goes Global: from Chile to Vietnam
20.06.2018 | Fraunhofer-Institut für Solare Energiesysteme ISE

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Temperature-controlled fiber-optic light source with liquid core

In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.

Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...

Im Focus: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Creating a new composite fuel for new-generation fast reactors

20.06.2018 | Materials Sciences

Game-changing finding pushes 3D-printing to the molecular limit

20.06.2018 | Materials Sciences

Could this material enable autonomous vehicles to come to market sooner?

20.06.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>