University of Texas engineering researchers say they have made a big breakthrough in a tiny, tiny, tiny field.
A team, led by professor Yuebing Zheng, has patented a new technique for manipulating nanoparticles, allowing scientists to move around incredibly small pieces of gold, silicon and other materials. Those materials are used to build optical computers and tiny machines, and they could even be used in medicine in the near future to do such things as delivering medications.
How tiny are these particles? Well, we probably would need to say tiny nine times in a row. Nanoparticles are between one and 100 nanometers. One nanometer is one billionth of a meter, or 10-9 meters — or, to harken back to SAT analogies, about what a tennis ball is to the Earth.
The particles are small enough that they exist on the scale between microscopic objects and atoms. That is the point at which the behavior of matter changes, said Sanjay Banerjee, director of the Microelectronics Research Center at UT. The very laws of physics make objects behave differently at the nanoscale level than they do at the microscopic or atomic level.
“Things at the nanoscale aren’t just smaller,” Banerjee said, “they have different properties.”
Such tiny particles could be combined into “meta materials” with properties that don’t exist in nature, Zheng said when the university announced the publication of the findings in the Jan. 13 issue of the science journal Nano Letters.
As an example of another use that could soon be available, Banerjee pointed to ultraefficient, light-emitting diodes that are beginning to replace traditional light bulbs. LEDs already consume far less energy than traditional light bulbs. They tend to last between 10,000 and 100,000 hours, compared with 2,000 hours for traditional bulbs. Nanoparticles could allow LEDs to be made from even tinier materials. And because nanoparticles of different sizes produce different colors, if the particles could be moved precisely, they could also be used create intricate patterns of, say, red, green and blue. They have even been used to mimic something very close to natural sunlight.
Nanoparticles can also be made from magnetic materials, such as cobalt. Though still too expensive for widespread use in the foreseeable future, magnetic nanoparticles could be used in special cases to create ultraefficient hard discs for storing information, Banerjee said.
Working with such tiny particles is tough, though. The most-used methods aren’t precise enough to reliably move them to a specific location or to keep them there. The way the researchers found to move those particles around is called “bubble pen lithography,” according to the press release. Basically, they used a tiny laser to create and move a tiny bubble of vaporized water. The bubble attracts the nanoparticle, which the laser then steers to a particular spot.
How precise is it? In a video, the researchers use the laser-bubble to capture a collection of nanoparticles and then move the bubble around, leaving behind the particles in a pattern — the Longhorn symbol, of course.