Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Microstructure-induced biomechanical responses of dragonfly wing veins

03.06.2011
Wang's research team discovered the sandwich microstructure of dragonfly wing veins [Wang et al. Compos Sci & Technol, 2008; 68: 186-192] and recently revealed the organic junction between these longitudinal veins and membranes of the dragonfly wing [Chen and Wang et al. Chinese Sci Bull, 2011; 56: 1658-1660].

Based on observed microstructural model and previously reported model about the main longitudinal veins and membrane, in which the former is based on the tubular model with sandwich structure in thickness of tubular, and the latter is based on the sample tubular model with the same material in thickness of tubular, they were used to simulate and characterize the biomechanical responses of dragonfly wings under symmetrical loading.

The results indicated that the effect of different microstructural models on the flapping frequency, trajectories, and corrugated and torsional behaviors of the wing cannot be ignored. This is because the sandwich microstructure, consisting of soft matter with fibers in the protein layer and hierarchical structure in the chitin layer, of the longitudinal vein plays an important role in improving aerodynamic efficiency by creating self-adaptability in the flapping, torsion and camber variations of the wing as it twists. Understanding the complete structure of the wing, including the microstructural features and the organic junction between veins and membranes, provides new insight into the flight mechanism of the dragonfly and the wing's biomechanical responses, as shown by the study reported in issue 56 of the Chinese Science Bulletin and to be reported in the future.

The organic junction with the hierarchical microstructure optimizes the dragonfly wing's biomechanics including to the strength, stiffness and toughness (see Figure 1). The organic junctions enable the corrugation of the total wing along the chord direction, which improves the warping rigidity, while the hierarchical microstructure at the nano scale in the thickness of chitin layer increases the flapping strength of the wing and lift coefficients, but not the torsional rigidity of wing. As the dragonfly wings twist during flapping process, the soft matter with fibers in the protein layer at the micro scale assists the turning performance and allows structural responses between the longitudinal veins and membranes that form the camber of the wing during the three dimensional changes. The camber and zigzag cross-section along the chord direction could enhance the aerodynamic efficiency of the wing [Ennos AR. J Exp Bio, 1988, 140: 137-160; Sane SP. J Exp Bio, 2003; 206: 4191-4208] by creating more vortices under upstrokes and downstrokes, as shown in Figure 2. Moreover, the corrugated wing has an important effect on torsion deformation under sample aerodynamic loading, and it is more flexible than a wing without sandwich longitudinal veins. Thus, the organic junction between the vein and membrane contributes to the dragonfly wing's remarkable biomechanical behavior. In addition, with the help of these two salient features, the wing can easily adjust the its chordwise length by changing the corrugated angle and allowing response to different flight environments. Although it is highly speculative, we believe that the wing possesses some self-adaptabilities to cope with the challenges of flight. From the view of energy, the authors suggest that this kind of self-adaptability helps the dragonfly reduce the amount of energy consumed during flight. Potentially, this research could inspire engineers to design self-adaptable and energy-saving flexible wings for micro aerial vehicles.

The authors are affiliated to the Department of Engineering Mechanics, School of Aerospace, Tsinghua University. This laboratory is conducting research mainly in biomechanics, fatigue damage and fracture mechanics of advanced materials.

Xi Shu Wang | EurekAlert!
Further information:
http://www.tsinghua.edu.cn

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>