Dr. Chunlei Guo at the University of Rochester has developed a method of altering the properties of metal so that it will even help water defy gravity. The trick is in changing the metal using a laser,but not just any laser – a femtosecond laser.
Dr. Guo is a professor of optics at the University of Rochester. He and his assistant, Anatoliy Vorobyev have been experimenting with the effect that a femtosecond laser has on metal. He has changed the color of such metals as Platinum, silver and aluminum by changing the properties of the metals using the laser. The femtosecond laser works as follows:
A femtosecond laser produces pulses lasting only a few quadrillionths of a second — a femtosecond is to a second what a second is to about 32 million years. During its brief burst, Guo’s laser unleashes as much power as the entire electric grid of North America does, all focused onto a spot the size of a needlepoint.
The laser causes the surface properties of the metal to change by forming nanostructures on the surface. These nanostructures can change the color of silver to blue permanently or allow metal to redirect water to flow up instead of down.
This research has profound effects. For instance, changing the surface of a microchip so that it can be cooled by minute drops of water that flow around the chip without touching it. Or altering the metal in hospitals, clinics, doctor’s offices and research labs so that it repels bacteria or other substances.
The laser can create nanoscale pits, strands and globules on the metal changing the way metal molecules and liquid molecules react. The water can be attracted, repelled or channeled through microscopic groves.
Dr. Guo and his assistant are working to refine the laser process and are exploring further ways that the femtosecond laser can alter metals for new or improved uses. Besides permanently changing the color of silver and platinum, altering the normal reactions of water and metal, he has also changed the tungsten filament in an incandescent light bulb.
The nanostructures built on the filament by the laser, allow normal incandescent bulbs to become brighter and even change the color of the light. By developing a 60 watt bulb that emits the light of a 100 watt bulb cuts down on the energy needed to provide more light making incandescent light bulbs more efficient.
There is no telling where this research may eventually lead. Who knows what inventions or un-thought of uses this technology may hold.
Photo from the University of Rochester Institute of Optics