Research lead
Scientists of the University of Twente have developed a method for speeding up fluid flows in microfluidics systems. The technique also makes it possible to mix fluids in situ without the need for external devices.
The researchers, led by Claus-Dieter Ohl of the MESA+ Institute for Nanotechnology, have harnessed cavitation effects in the new technique. A laser is used to induce the formation of bubbles in the micro channel, through local heating and low pressure.
These bubbles have a short life, rapidly imploding. This causes the fluid to flow at up to 20 metres per second. Near a channel wall, the effect is more marked and a jet is formed, creating strong circular flows, and thus mixing fluids.
In microfluidics different physical laws apply from those in force in larger-scale systems. Viscous forces take over, meaning that additional components – for example micromechanical devices – are needed for mixing and speeding up flow. These components, in turn, require additional electronics and wiring, adding complexity to lab-on-a-chip systems.
The laser can be directed to any spot where mixing or acceleration is needed. The MESA+ scientists therefore believe their new system will be a powerful tool in microfluidics and lab-on-a-chip systems.
The research was carried out by a multidisciplinary team from the MESA+ Institute for Nanotechnology of the University of Twente, the Physics of Fluids group of Professor Detlef Lohse and the BIOS Lab-on-a-chip group of Professor Albert van den Berg.
The project website has more details of potential applications.
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