. 24/7 Space News .
SPACE TRAVEL
Conch shells may inspire better helmets, body armor
by Staff Writers
Boston MA (SPX) May 29, 2017


Researchers at MIT have explored the secrets behind the conch shell's extraordinary impact resilience. The findings are reported in a new study by MIT graduate student Grace Gu (right), postdoc Mahdi Takaffoli (left), and McAfee Professor of Engineering Markus Buehler. Photo: Melanie Gonick/MIT

The shells of marine organisms take a beating from impacts due to storms and tides, rocky shores, and sharp-toothed predators. But as recent research has demonstrated, one type of shell stands out above all the others in its toughness: the conch.

Now, researchers at MIT have explored the secrets behind these shells' extraordinary impact resilience. And they've shown that this superior strength could be reproduced in engineered materials, potentially to provide the best-ever protective headgear and body armor.

The findings are reported in the journal Advanced Materials, in a paper by MIT graduate student Grace Gu, postdoc Mahdi Takaffoli, and McAfee Professor of Engineering Markus Buehler.

Conch shells "have this really unique architecture," Gu explains. The structure makes the material 10 times tougher than nacre, commonly known as mother of pearl. This toughness, or resistance to fractures, comes from a unique configuration based on three different levels of hierarchy in the material's internal structure.

The three-tiered structure makes it very hard for any tiny cracks to spread and enlarge, Gu says. The material has a "zigzag matrix, so the crack has to go through a kind of a maze" in order to spread, she says.

Until recently, even after the structure of the conch shell was understood, "you couldn't replicate it that well. But now, our lab has developed 3-D printing technology that allows us to duplicate that structure and be able to test it," says Buehler, who is the head of the Department of Civil and Environmental Engineering.

Part of the innovation involved in this project was the team's ability to both simulate the material's behavior and analyze its actual performance under realistic conditions. "In the past, a lot of testing [of protective materials] was static testing," Gu explains. "But a lot of applications for military uses or sports involve highly dynamic loading," which requires a detailed examination of how an impact's effects spread out over time.

For this work, the researchers did tests in a drop tower that enabled them to observe exactly how cracks appeared and spread - or didn't spread - in the first instants after an impact. "There was amazing agreement between the model and the experiments," Buehler says.

That's partly because the team was able to 3-D print composite materials with precisely controlled structures, rather than using samples of real shells, which can have unpredictable variations that can complicate the analysis. By printing the samples, "we can use exactly the same geometry" as used in the computer simulations, "and we get very good agreement." Now, in continuing the work, they can focus on making slight variations "as a basis for future optimization," Buehler says.

To test the relative importance of the three levels of structure, the team tried making variations of the material with different levels of hierarchy. Higher levels of hierarchy are introduced by incorporating smaller length-scale features into the composite, as in an actual conch shell. Sure enough, lower-level structures proved to be significantly weaker than the highest level pursued in this study, which consisted of the cross-lamellar features inherent in natural conch shells.

Testing proved that the geometry with the conch-like, criss-crossed features was 85 percent better at preventing crack propagation than the strongest base material, and 70 percent better than a traditional fiber composite arrangement, Gu says.

Protective helmets and other impact-resistant gear require a key combination of both strength and toughness, Buehler explains. Strength refers to a material's ability to resist damage, which steel does well, for example. Toughness, on the other hand, refers to a material's ability to dissipate energy, as rubber does. Traditional helmets use a metal shell for strength and a flexible liner for both comfort and energy dissipation. But in the new composite material, this combination of qualities is distributed through the whole material.

"This has stiffness, like glass or ceramics," Buehler says, but it lacks the brittleness of those materials, thanks to the integration of materials with different degrees of strength and flexibility within the composite structure. Like plywood, the composite is made up of layers whose "grain," or the internal alignment of its materials, is oriented differently from one layer to the next.

Because of the use of 3-D printing technology, this system would make it possible to produce individualized helmets or other body armor. Each helmet, for example, could be "tailored and personalized; the computer would optimize it for you, based on a scan of your skull, and the helmet would be printed just for you," Gu says.

The research was supported by the Office of Naval Research, a National Defense Science and Engineering Graduate Fellowship, the Defense University Research Instrumentation Program (DURIP), the Institute for Soldier Nanotechnologies (ISN), and the Natural Sciences and Engineering Research Council of Canada.

Research paper

SPACE MEDICINE
Researchers create artificial materials atom-by-atom
Helsinki, Finland (SPX) Mar 29, 2017
Researchers at Aalto University have manufactured artificial materials with engineered electronic properties. By moving individual atoms under their microscope, the scientists were able to create atomic lattices with a predetermined electrical response. The possibility to precisely arrange the atoms on a sample bring 'designer quantum materials' one step closer to reality. By arranging atoms in ... read more

Related Links
Massachusetts Institute of Technology
Space Tourism, Space Transport and Space Exploration News


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

SPACE MEDICINE
Conch shells may inspire better helmets, body armor

MIT researchers engineer shape-shifting food

DARPA Picks Design for Next-Generation Spaceplane

SDL-Supported SmallSat Launched from International Space Station

SPACE MEDICINE
Successful launch puts New Zealand in space race

Russia to create new Super-Heavy Class rocket after 2025

Neptune: Neutralizer-free plasma propulsion

Spaceflight buys Electron Rocket from Rocket Lab

SPACE MEDICINE
Preparations Continue Before Driving into 'Perseverance Valley'

Schiaparelli landing investigation completed

HI-SEAS Mission V Mars simulation marks midway point

Deciphering the fluid floorplan of a planet

SPACE MEDICINE
California Woman Charged for Trying to Hand Over Sensitive Space Tech to China

A cabin on the moon? China hones the lunar lifestyle

China tests 'Lunar Palace' as it eyes moon mission

China to conduct several manned space flights around 2020

SPACE MEDICINE
Government space program spending reaches 62B dollars in 2016

New Target Date for Second Iridium NEXT Launch

Satellite industry supports FCC proposal to reduce internet regulations for service providers

AsiaSat 9 ready for shipment

SPACE MEDICINE
New Zealand company partners with U.S. Army for engineered skin

New method allows real-time monitoring of irradiated materials

Neutron lifetime measurements take new shape for in situ detection

Solving the riddle of the snow globe

SPACE MEDICINE
Water forms superstructure around DNA, new study shows

How RNA formed at the origins of life

NASA Scientist Parlays Experience to Build Ocean Worlds Instrument

Scientists propose synestia, a new type of planetary object

SPACE MEDICINE
A whole new Jupiter with first science results from Juno

First results from Juno show cyclones and massive magnetism

Jupiters complex transient auroras

NASA's Juno probe forces 'rethink' on Jupiter









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.