Featured Research

from universities, journals, and other organizations

High-speed camera captures dancing droplets for scientific 'photo album'

Date:
August 6, 2013
Source:
Cornell University
Summary:
The splash from rain hitting a windowpane or printer ink hitting paper all comes down to tiny droplets hitting a surface, and what each of those droplets does. Researchers have produced a high-resolution “photo album” of more than 30 shapes an oscillated drop of water can take. The results, a fundamental insight into how droplets behave, could have applications in everything from inkjet printing to microfluidics.

Water droplet patterns were captured by a high-speed camera at Cornell University.
Credit: Cornell University

The splash from rain hitting a windowpane or printer ink hitting paper all comes down to tiny droplets hitting a surface, and what each of those droplets does. Cornell University researchers have produced a high-resolution "photo album" of more than 30 shapes an oscillated drop of water can take. The results, a fundamental insight into how droplets behave, could have applications in everything from inkjet printing to microfluidics.

Susan Daniel, assistant professor of chemical and biomolecular engineering, led the study, to be published in Physical Review E, Aug. 9. First author Chun-Ti Chang, a Cornell graduate student, designed and performed the experiments, which involved a high-speed, high-resolution camera. Paul Steen, professor of chemical and biomolecular engineering, and his former student, Josh Bostwick, led the theoretical portion of the study.

"What is really special about this study is the high-quality imaging we were able to capture of these oscillating droplets," Daniel said. "We created an imaging platform where we could look at the drop from the top, to enable us to see the characteristic shapes better than anyone has before."

The imaging platform, which Chang has named the "Omniview" because of the different angles at which the droplet can be observed, consists of a glass slide, the droplet sitting on top, and a 50-micron-square metal mesh, like a window screen, underneath. A light is shined through the mesh holes, and deflection of the drop's surface refracts the light, which is seen as a deformation of the mesh and captured by a high-speed camera.

The researchers mechanically oscillated the drops at varying frequencies, and observed and recorded their movements. The oscillation can be likened to when a violin string is plucked; certain natural frequencies correspond to a given length of string, the same way certain frequencies correspond to the shape of a drop of a specific size.

The researchers created a detailed table of droplet shapes according to frequency, as well as comparing these results to previous theoretical predictions involving the dynamics of oscillating droplets. Classical theories don't capture the dynamics entirely, but new predictions, made by collaborators Steen and Bostwick, take into account the physical effect of the solid substrate in contact with the droplet and match the images in the photo album.

The researchers also observed that some of the droplets take on multiple shapes when vibrated with a single driving frequency -- akin to physicists observing two different energy states simultaneously in an excited molecule.

"Without the high-speed imaging, we wouldn't have been able to see the drops exhibiting these kinds of mixed behaviors," Daniel said.

The detailed, clear table of oscillating drop modes should lend insight into further fundamental studies, as well as a host of applications, Daniel said. For example, NASA is interested in understanding how droplets on surfaces move in low gravity. And in high-resolution printing, the spread of a drop as it touches a surface will dictate image resolution. The surface chemistry of the roller, printer and ink will have profound effects on the technology.

More images and animations: https://cornell.app.box.com/droplets


Story Source:

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


Journal Reference:

  1. Chun-Ti Chang, Joshua B. Bostwick, Paul H. Steen, and Susan Daniel. Substrate constraint modifies the Rayleigh spectrum of vibrating sessile drops. Physical Review E, 2013

Cite This Page:

Cornell University. "High-speed camera captures dancing droplets for scientific 'photo album'." ScienceDaily. ScienceDaily, 6 August 2013. <www.sciencedaily.com/releases/2013/08/130806132536.htm>.
Cornell University. (2013, August 6). High-speed camera captures dancing droplets for scientific 'photo album'. ScienceDaily. Retrieved April 21, 2014 from www.sciencedaily.com/releases/2013/08/130806132536.htm
Cornell University. "High-speed camera captures dancing droplets for scientific 'photo album'." ScienceDaily. www.sciencedaily.com/releases/2013/08/130806132536.htm (accessed April 21, 2014).

Share This



More Matter & Energy News

Monday, April 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Why Did Nike Fire Most Of Its Nike FuelBand Team?

Newsy (Apr. 19, 2014) Nike fired most of its Digital Sport hardware team, the group behind Nike's FuelBand device. Could Apple or an overcrowded market be behind layoffs? Video provided by Newsy
Powered by NewsLook.com
Small Reactors Could Be Future of Nuclear Energy

Small Reactors Could Be Future of Nuclear Energy

AP (Apr. 17, 2014) After the Fukushima nuclear disaster, the industry fell under intense scrutiny. Now, small underground nuclear power plants are being considered as the possible future of the nuclear energy. (April 17) Video provided by AP
Powered by NewsLook.com
Horseless Carriage Introduced at NY Auto Show

Horseless Carriage Introduced at NY Auto Show

AP (Apr. 17, 2014) An electric car that proponents hope will replace horse-drawn carriages in New York City has also been revealed at the auto show. (Apr. 17) Video provided by AP
Powered by NewsLook.com
Honda's New ASIMO Robot, More Human-Like Than Ever

Honda's New ASIMO Robot, More Human-Like Than Ever

AFP (Apr. 17, 2014) It walks and runs, even up and down stairs. It can open a bottle and serve a drink, and politely tries to shake hands with a stranger. Meet the latest ASIMO, Honda's humanoid robot. Duration: 00:54 Video provided by AFP
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:
from the past week

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