Featured Research

from universities, journals, and other organizations

Straighten Up And Fly Right: Moths Benefit More From Flexible Wings Than Rigid

Date:
July 10, 2009
Source:
University of Washington
Summary:
New research using high-speed digital imaging shows that, at least for some insects, wings that flex and deform, something like what happens to a heavy beach towel when you snap it to get rid of the sand, are the best for staying aloft.

The wing of a Manduca sexta, or tobacco hawkmoth, reveals the extent of deformation during flight.
Credit: Armin Hinterwirth, University of Washington

Most scientists who create models trying to understand the mechanics and aerodynamics of insect flight have assumed that insect wings are relatively rigid as they flap.

Related Articles


New University of Washington research using high-speed digital imaging shows that, at least for some insects, wings that flex and deform, something like what happens to a heavy beach towel when you snap it to get rid of the sand, are the best for staying aloft.

"The evidence indicates that flexible wings are producing profoundly different air flows than stiff wings, and those flows appear to be more beneficial for generating lift," said Andrew Mountcastle, a UW doctoral student in biology.

He used particle image velocimetry, a technique commonly used to determine flow velocities in fluids, to study how air flows over the wings of Manduca sexta, or tobacco hawkmoths. The method combined laser light and high-speed digital video to model air flow.

A hawkmoth's wings are controlled by muscles on the insect's body and have no internal muscles of their own. The bulk of the wing is something like fabric stretched back from a stiff leading edge, fabric that is elastic and bends from inertia as the wing accelerates or decelerates through each stroke.

To test the wings' function, they were attached to mechanical "flappers" that moved back and forth 25 times a second, the same frequency at which the moths flap their wings, with the focus on how the wings deformed with each motion reversal. While the machine placed the wings at the same dominant angle as in normal moth flight, it could only approximate natural motion in one axis of rotation, compared with the three axes controlled in actual moth flight.

For the research, wings were removed from moths and tested in the mechanical "flapper" immediately, while they maintained most of their natural elasticity. After that the wings were allowed to dry for 12 to 24 hours and covered with enough spray paint to restore their original mass, then the wings were tested again in their more rigid state. The high-speed video, when viewed in slow motion, provided graphic detail of how the wings deformed as they flapped.

"That gave us two profoundly different deformations when we flapped the wings at natural wing-beat frequencies," Mountcastle said.

The "fresh," or flexible, wings had a mean deformation of 1.6 millimeters (about 64-thousandths of an inch) for each of five motion reversals, while the dry, stiff wings had a mean deformation of 1.15 millimeters (about 46-thousandths of an inch). By comparison, a freely hovering moth had a mean deformation of 1.52 millimeters (about 61-thousandths of an inch).

"Our results show that the flexible wings are doing a better job of generating lift-favorable momentum than are the stiff wings. They also are inducing airflow with greater overall velocity, which suggests the production of greater force for flight," Mountcastle said.

He is the lead author of a paper on the work, published in May in the journal Experiments in Fluids. Co-author is Thomas Daniel, a UW biology professor. The work was funded by the Defense Advanced Research Projects Agency, the National Science Foundation and the Joan and Richard Komen Endowed Chair.

"As a biologist, I am interested in the evolutionary implications of what we see here. To understand the selective pressures that have acted on wings through their evolution, we have to understand the functional implication of wing forms and their material properties," Mountcastle said.

He noted that insect wings have a wide variety of shapes and functions, and trying to understand how such diversity came about "is a really interesting biological question."

"There also is interest in developing tiny insect-like flapping robots, and certainly these results are relevant to that field," he said.


Story Source:

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


Journal Reference:

  1. Mountcastle et al. Aerodynamic and functional consequences of wing compliance. Experiments in Fluids, 2009; 46 (5): 873 DOI: 10.1007/s00348-008-0607-0

Cite This Page:

University of Washington. "Straighten Up And Fly Right: Moths Benefit More From Flexible Wings Than Rigid." ScienceDaily. ScienceDaily, 10 July 2009. <www.sciencedaily.com/releases/2009/06/090629200836.htm>.
University of Washington. (2009, July 10). Straighten Up And Fly Right: Moths Benefit More From Flexible Wings Than Rigid. ScienceDaily. Retrieved November 26, 2014 from www.sciencedaily.com/releases/2009/06/090629200836.htm
University of Washington. "Straighten Up And Fly Right: Moths Benefit More From Flexible Wings Than Rigid." ScienceDaily. www.sciencedaily.com/releases/2009/06/090629200836.htm (accessed November 26, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Wednesday, November 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Classic Hollywood Memorabilia Goes Under the Hammer

Classic Hollywood Memorabilia Goes Under the Hammer

Reuters - Entertainment Video Online (Nov. 26, 2014) The iconic piano from "Casablanca" and the Cowardly Lion suit from "The Wizard of Oz" fetch millions at auction. Sara Hemrajani reports. Video provided by Reuters
Powered by NewsLook.com
Pet Dogs to Be Used in Anti-Ageing Trial

Pet Dogs to Be Used in Anti-Ageing Trial

Reuters - Innovations Video Online (Nov. 26, 2014) Researchers in the United States are preparing to discover whether a drug commonly used in human organ transplants can extend the lifespan and health quality of pet dogs. Video provided by Reuters
Powered by NewsLook.com
From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

From Popcorn To Vending Snacks: FDA Ups Calorie Count Rules

Newsy (Nov. 25, 2014) The US FDA is announcing new calorie rules on Tuesday that will require everywhere from theaters to vending machines to include calorie counts. Video provided by Newsy
Powered by NewsLook.com
Feast Your Eyes: Lamb Chop Sent Into Space from UK

Feast Your Eyes: Lamb Chop Sent Into Space from UK

Reuters - Light News Video Online (Nov. 25, 2014) Take a stab at this -- stunt video shows a lamb chop's journey from an east London restaurant over 30 kilometers into space. Rough Cut (no reporter narration). 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


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