Scientists studying the behavior of platinum particles immersed in hydrogen peroxide may have discovered a new way to propel microscopic machines. The new mechanism is described in The Journal of Chemical Physics, which is produced by AIP Publishing.
Micro-sized machines operate under very different conditions than their macro-sized counterparts. The high surface-area-to-mass ratio of tiny motors means they require a constant driving force to keep them going. In the past, researchers have relied on asymmetric chemical reactions on the surface of the motors to supply the force.
For example, Janus motors, are spherical particles coated with a different material on each side. One of the sides is typically made of a catalyst like platinum, which speeds up the reaction that converts hydrogen peroxide into water and oxygen. When the Janus motor is immersed in hydrogen peroxide, oxygen bubbles form more quickly on the platinum side, pushing the sphere forward.
Researchers from Doshisha University in Kyoto, Japan have now discovered, however, that two-sided materials aren't necessary to make micromotors move. The researchers placed tiny spheres made only of platinum in hydrogen peroxide and observed the particles' movement through a microscope. Although the individual spheres bounced about randomly, the researchers noticed that clumps of particles began to exhibit regular motions.
The clumps shaped like teardrops moved forward, those that resembled windmills started to spin, and the boomerang shaped clumps traveled in a circle. After creating a theoretical model of the forces at work, the researchers realized they could explain the regular motions by the asymmetrical drag generated by the different shapes.
The researchers envision combining their new type of motors with existing motors to create easily controllable machines with a versatile range of motions.
Micro- and nano-sized machines may one day ferry drugs around the body or help control chemical reactions, but the Japanese team also sees a more fundamental reason to study such tiny systems.
"Micromotors may be used not only as a power source for micromachines and microfactories, but may also give us significant insight regarding mysterious living phenomenon," said Daigo Yamamoto, a researcher in the Molecular Chemical Engineering Laboratory at Doshisha University and an author on the paper that describes the new motors.
The article, " Catalytic micromotor generating self-propelled regular motion through random fluctuation" by Daigo Yamamoto, Atsushi Mukai, Naoaki Okita, Kenichi Yoshikawa and Akihisa Shioi appears in The Journal of Chemical Physics. See: http://dx.doi.org/10.1063/1.4813791
ABOUT THE JOURNAL
The Journal of Chemical Physics publishes concise and definitive reports of significant research in the methods and applications of chemical physics. See: http://jcp.aip.org
Jason Socrates Bardi | Source: EurekAlert!
Further information: www.aip.org
More articles from Physics and Astronomy:
Supernova Blast Provides Clues to Age of Binary Star System
05.12.2013 | Chandra X-ray Center
Glimpsing the Infrastructure of a Gamma-ray Burst Jet
05.12.2013 | NASA/Goddard Space Flight Center
The Light: Global study gets underway with online user survey
Light has a fundamental impact on our sense of well-being and performance. In cooperation with Zumtobel, a supplier of lighting solutions, Fraunhofer IAO has launched a global user survey of lighting quality in offices. The objective is to identify the best lighting conditions for a variety of spaces and lighting ...
Quantum entanglement, a perplexing phenomenon of quantum mechanics that Albert Einstein once referred to as “spooky action at a distance,” could be even spookier than Einstein perceived.
Physicists at the University of Washington and Stony Brook University in New York believe the phenomenon might be intrinsically linked with wormholes, hypothetical features of space-time that in popular science fiction can provide a much-faster-than-light shortcut from one part of the universe to another.
But here’s the catch: One couldn’t actually ...
A star is formed when a large cloud of gas and dust condenses and eventually becomes so dense that it collapses into a ball of gas, where the pressure heats the matter, creating a glowing gas ball – a star is born.
New research from the Niels Bohr Institute, among others, shows that a young, newly formed star in the Milky Way had such an explosive growth, that it was initially about 100 times brighter than it is now. The results are published in the scientific journal, Astrophysical Journal Letters.
The young ...
EPFL scientists have shown how to achieve a dramatic increase in the capacity of optical fibers; Their simple, innovative solution reduces the amount of space required between the pulses of light that transport data
Optical fibers carry data in the form of pulses of light over distances of thousands of miles at amazing speeds. They are one of the glories of modern telecommunications technology.
However, their capacity is limited, because the pulses of light need to be lined up one after the other in ...
NASA's Hurricane and Severe Storms Sentinel airborne mission known as HS3 wrapped up for the 2013 Atlantic Ocean hurricane season at the end of September, and had several highlights. HS3 will return to NASA’s Wallops Flight Facility in Wallops Island, Va., for the 2014 Atlantic hurricane season.
During the 2013 mission, two unmanned Global Hawks flew from Wallops for the first time. The mission highlights included studying the Saharan Air Layer, following the genesis of a tropical storm, finding a unique hybrid core or center circulation in a redeveloped storm, obtaining measurements on the strongest side of ...
05.12.2013 | Health and Medicine
05.12.2013 | Ecology, The Environment and Conservation
05.12.2013 | Information Technology
05.12.2013 | Event News
04.12.2013 | Event News
12.11.2013 | Event News