Designing structures and devices that protect the body from shock and vibrations during high-velocity impacts is a universal challenge.
Scientists and engineers focusing on this challenge might make advances by studying the unique morphology of the woodpecker, whose body functions as an excellent anti-shock structure.
This is a schematic of the pecking process of a woodpecker and the Mises stress at different times: (a) and (e) are moments of readiness to peck; (b) and (d) are the moments of departure and return, respectively; (c) is the moment of collision; arrows on the beaks show velocity direction.
Credit: ©Science China Press
The woodpecker's brain can withstand repeated collisions and deceleration of 1200 g during rapid pecking. This anti-shock feature relates to the woodpecker's unique morphology and ability to absorb impact energy.
Using computed tomography and the construction of high-precision three-dimensional models of the woodpecker, Chinese scientists explain its anti-shock biomechanical structure in terms of energy distribution and conversion.
Their findings, presented in a new study titled "Energy conversion in the woodpecker on successive pecking and its role in anti-shock protection of the brain" and published in the Beijing-based journal SCIENCE CHINA Technological Sciences, could provide guidance in the design of anti-shock devices and structures for humans.
To build a sophisticated 3D model of the woodpecker, scientist Wu Chengwei and colleagues at the State Key Lab of Structural Analysis for Industrial Equipment, part of the Department of Engineering Mechanics at the Dalian University of Technology in northeastern China, scanned the structure of the woodpecker and replicated it in remarkable detail.
"CT scanning technology can be used to obtain the images of internal structures of objects … which is widely used in the medical field and expanded to mechanical modeling of biological tissue," they explain in the study.
"Based on the CT scanning technology (CT scanner, LightSpeed VCT XT, GE, USA), detailed inner structure images of the head were obtained and then imported to Mimics software to form a scattered-points model," they state. "Then a geometric model of the head was set up using the facet feature and remodeling module of Pro/E for the surface fitting. After the geometric repairs, the FE [finite element] model meshed by tetrahedron elements was established using Abaqus software."
The woodpecker's structure was recreated through intricate geometric modeling. "The final FE model has 940000 fine elements with a minimum size of 0.07 mm in the head, 70000 coarse elements with a maximum size of 3.5 mm in the body and 20000 elements with a minimum size of 0.16 mm in the trunk," the researchers state.
Discoveries made during the study could have applications in the design of spacecraft, automobiles, and wearable protective gear, explains Professor Wu.
"High-speed impacts and collisions can destroy structures and materials," Wu states. "In the aerospace industry, spacecraft face the constant danger of collisions with space debris and micrometeoroids," Wu adds. "If a spacecraft's structure or scientific instruments were destroyed by impact, the economic loss would be huge."
In cities worldwide, Wu says, automobile accidents are a persistent threat to human safety, and head injuries are common.
Challenges presented in minimizing these threats and injuries have led to widespread efforts to understand and replicate or improve on anti-shock mechanisms found in nature.
The woodpecker stands out in this field of study: it can peck trees at high frequency (up to 25 Hz) and high speed (up to 7 m/s and 1200 g deceleration) without suffering any brain injury.
"This unique anti-shock ability inspires scientists to uncover the related bio-mechanisms," Wu states, for potential engineering of similar devices and structures based on principles of biomimicry.
Wu and colleagues used 3D models of the woodpecker to test how impact energy was handled by its specially adapted structure.
Figure 1 shows the pecking process of a woodpecker and the Mises stress at different times.
The results showed that the body not only supports the woodpecker to peck on the tree, but also stores the majority of the impact energy in the form of strain energy, significantly reducing the quantity of impact energy that enters the brain.
"Most of the impact energy in the pecking is converted into the strain energy stored in the body (99.7%) and there is only a small fraction of it in the head (0.3%)," the researchers reported.
Structures in the head including the beak, skull, and hyoid bone further reduce the strain energy of the brain. The small fraction of impact energy that enters the brain will be eventually dissipated in form of heat, causing a rapid temperature increment in the brain. As a consequence of this, the woodpecker has to peck intermittently.
This research project received funding in the form of grants from the National Science Foundation of China (Grant No. 11272080), the Doctoral Education Foundation of China Education Ministry (Grant No. 20110041110021), and the Fundamental Research Funds for the Central Universities of China (Grant No. DUT14LK36).
See the article: Zhu Zhaodan, Zhang Wei and Wu Chengwei. "Energy conversion in the woodpecker on successive peckings and its role on anti-shock protection of the brain."
SCIENCE CHINA Technological Science. 2014, 57(7): 1269-1275. http://link.springer.com/article/10.1007%2Fs11431-014-5582-5
SCIENCE CHINA Technological Science is produced by Science China Press, a leading publisher of scientific journals in China that operates under the auspices of the Chinese Academy of Sciences. Science China Press presents to the world leading-edge advancements made by Chinese scientists across a spectrum of fields. http://www.scichina.com/english/
Wu Chengwei | Eurek Alert!
Multi-year study finds 'hotspots' of ammonia over world's major agricultural areas
17.03.2017 | University of Maryland
Diabetes Drug May Improve Bone Fat-induced Defects of Fracture Healing
17.03.2017 | Deutsches Institut für Ernährungsforschung Potsdam-Rehbrücke
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
29.03.2017 | Materials Sciences
29.03.2017 | Physics and Astronomy
29.03.2017 | Earth Sciences