June 9, 2009

Scientists make metal that guides liquids

U.S. physicists are using an ultra-fast laser to create metal that can attract, repel and guide liquids.

University of Rochester scientists said they are able to create a simple slab of metal that lifts liquid using the same principle as do trees to lift water from the ground -- capillary action -- but at a much faster rate, the researchers said.

Associate Professor Chunlei Guo, who led the study, and researcher Anatoliy Vorobyev, use an ultra-fast burst of femtosecond laser light to change the surface of a metal, forming nanoscale and microscale pits, globules and strands across the metal's surface.

Imagine a huge waterway system shrunk down onto a tiny chip, like the electronic circuit printed on a microprocessor, so we can perform chemical or biological work with a tiny bit of liquid, Guo said. Blood could precisely travel along a certain path to a sensor for disease diagnostics. With such a tiny system, a nurse wouldn't need to draw a whole tube of blood for a test. A scratch on the skin might contain more than enough cells for a micro-analysis.

The research is to appear in an upcoming issue of the journal Applied Physics Letters.