Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Laser-induced bubbles liven things up in lab-on-a-chip

24.05.2007
Thanks to tiny and rapidly imploding gas bubbles, scientists of the University of Twente succeed in speeding up the fluid flow in a micro channel.

Apart from that, the bubbles form a strong new way of mixing fluids within a lab-on-a-chip, without the need of complicated external components. The scientists led by dr. Claus-Dieter Ohl of the MESA+ Institute for Nanotechnology present their results in a June 2007 edition of Physical Review Letters.

‘Controlled cavitation’ is the basis for the new technique: using a laser, a bubble is induced in the micro channel, by local heating and low pressure. This bubble has a short life: it rapidly implodes caused by the higher pressure in the channel. This causes the fluid flow to go up to 20 meters per second. Near a channel wall, the effect is spectacular. There a jet is formed, together with to tiny bubbles around which a strong circular flow forms. This is an ideal way of mixing fluids.

Simple and fast

In micro fluidics, other physical laws become dominant over those valid for large-scale systems. Viscous forces take over, and this implies that often additional components –for example micromechanical devices- are necessary for mixing and speeding up the flow. Those components , in turn, require additional electronics and wiring and can make a lab-on-a-chip fairly complicated. The laser can be directed to any spot where mixing or acceleration is needed, this is even made easier by the fact that micro fluidic systems are often transparent. The MESA+ scientists therefore see their new approach as a powerful new tool in micro fluidics and lab-on-a-chip systems.

The special project website http://stilton.tnw.utwente.nl/people/ohl/controlled_cavitation.html

shows some videos about the application of the bubbles in various geometries.

The research has been done in a multidisciplinary team of scientists from the MESA+ Institute for Nanotechnology of the University of Twente: from the Physics of Fluids group of prof. Detlef Lohse and the BIOS Lab-on-a-chip group of prof. Albert van den Berg. They cooperated with Shimadzu Europe.

Wiebe van der Veen | alfa
Further information:
http://www.utwente.nl

More articles from Physics and Astronomy:

nachricht Seeing the quantum future... literally
16.01.2017 | University of Sydney

nachricht Airborne thermometer to measure Arctic temperatures
11.01.2017 | Moscow Institute of Physics and Technology

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: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

Im Focus: Bacterial Pac Man molecule snaps at sugar

Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.

The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...

Im Focus: Newly proposed reference datasets improve weather satellite data quality

UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration

"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...

Im Focus: Repairing defects in fiber-reinforced plastics more efficiently

Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.

Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Multiregional brain on a chip

16.01.2017 | Power and Electrical Engineering

New technology enables 5-D imaging in live animals, humans

16.01.2017 | Information Technology

Researchers develop environmentally friendly soy air filter

16.01.2017 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>