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 Smallest transistor worldwide switches current with a single atom in solid electrolyte
17.08.2018 | Karlsruher Institut für Technologie (KIT)

nachricht Protecting the power grid: Advanced plasma switch for more efficient transmission
17.08.2018 | DOE/Princeton Plasma Physics Laboratory

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: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Quantum bugs, meet your new swatter

20.08.2018 | Information Technology

A novel synthetic antibody enables conditional “protein knockdown” in vertebrates

20.08.2018 | Life Sciences

Metamolds: Molding a mold

20.08.2018 | Information Technology

VideoLinks
Science & Research
Overview of more VideoLinks >>>