Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Researchers find the macroscopic Brownian motion phenomena of self-powered liquid metal motors

02.07.2015

Classical Brownian motion theory was established over one hundred year ago, describing the stochastic collision behaviors between surrounding molecules. Recently, researchers from Technical Institute of Physics and Chemistry, Chinese Academy of Sciences discovered that the self-powered liquid metal motors in millimeter scale demonstrated similar Brownian like motion behaviors in alkaline solution. And the force comes from the hydrogen gas stream generated at the interface between liquid metal motor and its contacting substrate bottom.

Ever since the irregular motions of suspended grains in water was observed by Brown in 1827, tremendous efforts have been made on establishing a theory to characterize the Brownian motion. After almost a half century later, the kinetic theories of heat developed by Maxwell, Boltzmann and others were merging as a possible explanation.


This video shows hydrogen bubble tails generated from a swarm of self-powered liquid metal tiny motors which were distinguished through high contrast optical images. It indicates that these tiny motors kept swiftly traveling here and there, just like a fairy.

Credit: ©Science China Press

In 1905, Einstein published a theoretical paper interpreting the stochastic process using particle diffusion constant and the fluid viscosity. This relationship bridges the microscopic dynamics with the macroscopic phenomenon, which inspired many subsequent works regarding both thermodynamics and statistical physics. Such theory was later demonstrated by the well-known Perrin's experiments.

So far, most of the classical Brownian motions refer to the molecules activities that occur in microscale. There are very limited reports to investigate such phenomena in macroscale. And the ever tackled phenomena are mainly focused on the particle motions caused by the surrounding liquid molecules.

In this study, researchers disclosed that macroscopic liquid metal motors in millimeter scale showed similar Brownian motion behavior in alkaline solution. The authors dispersed the premixed liquid metal and Al (mass percentage 1%) alloy into a glass Petri dish. It was observed that each tiny motor in millimeter scale began to move swiftly and randomly on Petri dish glass.

Contrary to the classical Brownian motion behavior, the main driving force of such motion comes from the hydrogen bubbles generated at the bottom of the tiny motors. Such tiny motor differs in moving mechanism with its counterpart large size self-fueled liquid metal machine which was mainly driven by the electrochemically induced surface tension.

Further, an optical platform with high image contrast, which works somewhat like the Wilson Cloud Chamber, was introduced to clearly depict the hydrogen bubble stream left behind the running motors.

The present findings add important new knowledge to the liquid metal motor as well as the classical Brownian motion phenomenon. The established optical image contrast method also provides an important experimental tool for further investigations along this direction.

###

This research was partially supported by the Research Funding of the Chinese Academy of Sciences (No. KGZD-EW-T04-4).

See the article:

B. Yuan, S. Tan, Y. Zhou, J. Liu, "Self-powered macroscopic Brownian motion of spontaneously running liquid metal motors," Sci. Bull. (2015) 60(13):1203-1210. http://link.springer.com/article/10.1007%2Fs11434-015-0836-6

Liu Jing | EurekAlert!

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>