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.
This image shows a possible application of chemical micromotors.
Credit: Daigo Yamamoto/Doshisha
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 | EurekAlert!
Exploring the mysteries of supercooled water
01.03.2017 | American Institute of Physics
Optical generation of ultrasound via photoacoustic effect
01.03.2017 | American Institute of Physics
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.
On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...
In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport
Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...
The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.
The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...
13.02.2017 | Event News
10.02.2017 | Event News
09.02.2017 | Event News
01.03.2017 | Health and Medicine
01.03.2017 | Physics and Astronomy
01.03.2017 | Life Sciences