Featured Research

from universities, journals, and other organizations

Spontaneous combustion in nanobubbles inspires compact ultrasonic loudspeaker

Date:
September 29, 2011
Source:
University of Twente
Summary:
Nanometer-sized bubbles containing the gases hydrogen and oxygen can apparently combust spontaneously, although nothing happens in larger bubbles. For the first time, researchers have demonstrated this spontaneous combustion. They intend to use the phenomenon to construct a compact ultrasonic loudspeaker.

Formation of bubbles at the electrodes during electrolysis (can be seen in a and b). Situations c, d, and e show the formation of both hydrogen and oxygen on the left, hydrogen alone in the middle and oxygen alone on the right. Situation e shows combustion taking place on the left. No bubbles can be seen on the electrodes.
Credit: Image courtesy of University of Twente

Nanometre-sized bubbles containing the gases hydrogen and oxygen can apparently combust spontaneously, although nothing happens in larger bubbles. For the first time, researchers at the University of Twente's MESA+ Institute for Nanotechnology have demonstrated this spontaneous combustion in a publication in Physical Review E. They intend to use the phenomenon to construct a compact ultrasonic loudspeaker.

Related Articles


The fact that a violent reaction takes place is already evident from the damage incurred by the electrodes with which the reaction is initiated. These electrodes are used to make hydrogen and oxygen by electrolysis, in the usual manner, in an ultra-small reaction chamber. If the plus and minus poles are continually alternated, tiny bubbles containing both gases arise.

The frequency with which the poles are alternated determines the size of the bubbles: the higher the frequency, the smaller the bubbles. Combustion only takes place in bubbles that are smaller than 150 nanometres (a nanometre is a millionth of a millimetre); nothing happens in larger bubbles. Early experiments in microreactors also showed that nothing happened in larger bubbles; the heat can dissipate to the larger internal surface.

Metres per second

Researcher Vitaly Svetovoy was working on the construction of an actuator for rapidly building pressure when he came across this phenomenon. Such actuators are, for example, used in loudspeakers for ultrasonic frequencies undetectable by the human ear in the medical world. None of the mechanical techniques currently available are suitable for making a very compact loudspeaker of this kind and still achieving a 'deflection' of metres per second on this scale. Svetovoy thought, however, that it might be possible by building up pressure with bubbles. The problem was that the bubbles could be made very rapidly but that they did not disappear quickly enough. The combustion reaction that has now been demonstrated might solve this problem. But it causes other problems too, such as the damage to the electrodes. "That is what we now have to look at," Svetovoy said.


Story Source:

The above story is based on materials provided by University of Twente. Note: Materials may be edited for content and length.


Journal Reference:

  1. Vitaly Svetovoy, Remko Sanders, Theo Lammerink, Miko Elwenspoek. Combustion of hydrogen-oxygen mixture in electrochemically generated nanobubbles. Physical Review E, 2011; 84 (3) DOI: 10.1103/PhysRevE.84.035302

Cite This Page:

University of Twente. "Spontaneous combustion in nanobubbles inspires compact ultrasonic loudspeaker." ScienceDaily. ScienceDaily, 29 September 2011. <www.sciencedaily.com/releases/2011/09/110928185909.htm>.
University of Twente. (2011, September 29). Spontaneous combustion in nanobubbles inspires compact ultrasonic loudspeaker. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2011/09/110928185909.htm
University of Twente. "Spontaneous combustion in nanobubbles inspires compact ultrasonic loudspeaker." ScienceDaily. www.sciencedaily.com/releases/2011/09/110928185909.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Matter & Energy News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Building Google Into Cars

Building Google Into Cars

Reuters - Business Video Online (Dec. 19, 2014) Google's next Android version could become the standard that'll power your vehicle's entertainment and navigation features, Reuters has learned. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com
AP Review: Nikon D750 and GoPro Hero 4

AP Review: Nikon D750 and GoPro Hero 4

AP (Dec. 19, 2014) What to buy an experienced photographer or video shooter? There is some strong gear on the market from Nikon and GoPro. The AP's Ron Harris takes a closer look. (Dec. 19) Video provided by AP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
Powered by NewsLook.com
Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins