Featured Research

from universities, journals, and other organizations

Cicadas get a jump on cleaning

Date:
April 29, 2013
Source:
Duke University
Summary:
As cicadas on the East Coast begin emerging from their 17-year slumber, a spritz of dew drops is all they need to keep their wings fresh and clean.

This image shows a dew-dropped cicada.
Credit: Duke University

As cicadas on the East Coast begin emerging from their 17-year slumber, a spritz of dew drops is all they need to keep their wings fresh and clean.

Related Articles


Researchers at Duke University and James Cook University in Australia have shown that dew drops can be beneficial not only in cleaning cicada wings, but other water-repellant surfaces. On these so-called superhydrophobic surfaces, dew drops "jump" by themselves, carrying away the contaminants.

A team led by Chuan-Hua Chen, Alfred M. Hunt Faculty Scholar and assistant professor of mechanical engineering and materials science at Duke's Pratt School of Engineering, demonstrated that tiny particles such as pollen can be removed from cicada wings by a phenomenon he has described as jumping droplets. When growing dew drops coalesce together, the merged drop jumps off water-repellant surfaces. The jumping motion is automatic, powered entirely by the surface energy initially stored in the dew drops.

Using a specially designed high-speed video imaging system, the engineers captured the jumping water droplets on a cicada wing, as well as the associated self-cleaning processes.

"The ability of water-repellant surfaces to self-clean has conventionally been attributed to rain droplets picking up dirt particles," Chen said. "For this conventional wisdom to work, rainfall must be present and the orientation has to be favorable for gravity to effectively remove the rain droplets. These limits severely restrict the practical use of self-cleaning superhydrophobic surfaces.

"We have found, however, that the self-propelled jumping motion of the dew drops is very effective in dislodging contaminating particles, regardless of the orientation," Chen said. "These new insights can help guide the development of man-made surfaces that are not dependent on any external forces and are therefore truly self-cleaning."

The results of Chen's research were published online in the journal Proceedings of the National Academy of Sciences. Katrina Wisdom, a Duke undergraduate and a Pratt Research Fellow in Chen's lab at the time of this study, was the paper's co-first author.

Cicadas are flying insects typically a few inches long. The most common species emerge on a yearly basis, with some U.S. species arriving every 17 years. When they dig out from underground as nymphs they molt, shedding their skin to reveal their wings. They then take flight as full-grown cicadas, spending the next four to six weeks flying around searching for and attracting mates with their distinctive song. After depositing eggs in the ground, the cicadas die and the cycle begins anew.

Cicada wings are characterized by rows and rows of tiny bumps or domes of various heights and widths. They look like upside-down ice cream cones, with the conical tips projecting upward. When a water droplet lands on this type of surface, it only touches the points of the bumps, creating pockets of air underneath the droplet. The droplet is kept aloft by this cushion of air, much like the puck in an air-hockey game.

"Most cicadas are unable to clean their own wings because of their short appendages," said Gregory Watson of James Cook University. "Furthermore, these insects commonly live in areas where there is little rain over an extended period of time. However, the areas are humid, which provides the tiny dew droplets needed to 'jump clean' their wings."

"These findings point to an alternative route to achieve self-cleaning which is fundamentally different from the conventional wisdom involving rolling or colliding droplets on a superhydrophobic surface," Chen said. "Self-cleaning surfaces using the jumping-drop mechanism can work at any orientation, which is a huge advantage for applications with unfavorable orientations with respect to gravity, such as mobile electronics and building roofs."


Story Source:

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


Journal Reference:

  1. Katrina M. Wisdom, Jolanta A. Watson, Xiaopeng Qu, Fangjie Liu, Gregory S. Watson, and Chuan-Hua Chen. Self-cleaning of superhydrophobic surfaces by self-propelled jumping condensate. PNAS, April 29, 2013 DOI: 10.1073/pnas.1210770110

Cite This Page:

Duke University. "Cicadas get a jump on cleaning." ScienceDaily. ScienceDaily, 29 April 2013. <www.sciencedaily.com/releases/2013/04/130429154101.htm>.
Duke University. (2013, April 29). Cicadas get a jump on cleaning. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2013/04/130429154101.htm
Duke University. "Cicadas get a jump on cleaning." ScienceDaily. www.sciencedaily.com/releases/2013/04/130429154101.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Anglerfish Rarely Seen In Its Habitat Will Haunt You

Newsy (Nov. 22, 2014) For the first time Monterey Bay Aquarium recorded a video of the elusive, creepy and rarely seen anglerfish. Video provided by Newsy
Powered by NewsLook.com
Raw: Buffalo Residents Digging Out, Helping out

Raw: Buffalo Residents Digging Out, Helping out

AP (Nov. 22, 2014) Hundreds of volunteers joined a 'shovel brigade' in Buffalo, New York on Saturday, as the city was living up to its nickname, "The City of Good Neighbors." Video provided by AP
Powered by NewsLook.com
Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

Toyota's Hydrogen Fuel-Cell Green Car Soon Available in the US

AFP (Nov. 21, 2014) Toyota presented its hydrogen fuel-cell compact car called "Mirai" to US consumers at the Los Angeles auto show. The car should go on sale in 2015 for around $60.000. It combines stored hydrogen with oxygen to generate its own power. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
Google Announces Improvements To Balloon-Borne Wi-Fi Project

Google Announces Improvements To Balloon-Borne Wi-Fi Project

Newsy (Nov. 21, 2014) In a blog post, Google said its balloons have traveled 3 million kilometers since the start of Project Loon. Video provided by Newsy
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


Plants & Animals

Earth & Climate

Fossils & Ruins

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