The lightweight skeletons of organisms such as sea sponges display a strength that far exceeds that of manmade products constructed from similar materials.
Scientists have long suspected that the difference has to do with the hierarchical architecture of the biological materials—the way the silica-based skeletons are built up from different structural elements, some of which are measured on the scale of billionths of meters, or nanometers. Now engineers at the California Institute of Technology (Caltech) have mimicked such a structure by creating nanostructured, hollow ceramic scaffolds, and have found that the small building blocks, or unit cells, do indeed display remarkable strength and resistance to failure despite being more than 85 percent air.
“Inspired, in part, by hard biological materials and by earlier work by Toby Schaedler and a team from HRL Laboratories, Caltech, and UC Irvine on the fabrication of extremely lightweight microtrusses, we designed architectures with building blocks that are less than five microns long, meaning that they are not resolvable by the human eye,” says Julia R. Greer, professor of materials science and mechanics at Caltech. “Constructing these architectures out of materials with nanometer dimensions has enabled us to decouple the materials’ strength from their density and to fabricate so-called structural metamaterials which are very stiff yet extremely lightweight.”
At the nanometer scale, solids have been shown to exhibit mechanical properties that differ substantially from those displayed by the same materials at larger scales. For example, Greer’s group has shown previously that at the nanoscale, some metals are about 50 times stronger than usual, and some amorphous materials become ductile rather than brittle. “We are capitalizing on these size effects and using them to make real, three-dimensional structures,” Greer says.
In an advance online publication of the journal Nature Materials, Greer and her students describe how the new structures were made and responded to applied forces.
The largest structure the team has fabricated thus far using the new method is a one-millimeter cube. Compression tests on the the entire structure indicate that not only the individual unit cells but also the complete architecture can be endowed with unusually high strength, depending on the material, which suggests that the general fabrication technique the researchers developed could be used to produce lightweight, mechanically robust small-scale components such as batteries, interfaces, catalysts, and implantable biomedical devices.
Greer says the work could fundamentally shift the way people think about the creation of materials. “With this approach, we can really start thinking about designing materials backward,” she says. “I can start with a property and say that I want something that has this strength or this thermal conductivity, for example. Then I can design the optimal architecture with the optimal material at the relevant size and end up with the material I wanted.”
The team first digitally designed a lattice structure featuring repeating octahedral unit cells—a design that mimics the type of periodic lattice structure seen in diatoms. Next, the researchers used a technique called two-photon lithography to turn that design into a three-dimensional polymer lattice. Then they uniformly coated that polymer lattice with thin layers of the ceramic material titanium nitride (TiN) and removed the polymer core, leaving a ceramic nanolattice. The lattice is constructed of hollow struts with walls no thicker than 75 nanometers.
“We are now able to design exactly the structure that we want to replicate and then process it in such a way that it’s made out of almost any material class we’d like—for example, metals, ceramics, or semiconductors—at the right dimensions,” Greer says.
The Latest Bing News on:
- Defects may help scientists understand the exotic physics of topologyon January 21, 2021 at 4:53 am
Real-world materials are usually messier than the idealized scenarios found in textbooks. Imperfections can add complications and even limit a material's usefulness. To get around this, scientists ...
- Groundbreaking New One-Step Process for Creating Self-Assembled Metamaterialson January 16, 2021 at 11:50 pm
In general, metamaterials are materials made in the lab to provide ... During what is called a “first-order structural phase transition” process, the material moved into a mixed-phase in which some ...
- Researchers develop new one-step process for creating self-assembled metamaterialson January 12, 2021 at 11:00 am
A team led by University of Minnesota Twin Cities researchers has discovered a groundbreaking one-step process for creating materials with unique properties, ca ...
- New One-Step Process Helps Create Tunable, Self-Assembled Metamaterialson January 12, 2021 at 7:33 am
Metamaterials are essentially materials that are created ... During the so-called “first-order structural phase transition” process, the novel material changed to a mixed-phase, where certain portions ...
- New one-step process for creating self-assembled metamaterialson January 11, 2021 at 12:06 pm
In general, metamaterials are materials made in the ... During what is called a "first-order structural phase transition" process, the material moved into a mixed-phase in which some parts of ...
- Researchers develop new one-step process for creating self-assembled metamaterialson January 10, 2021 at 4:00 pm
During what is called a “first-order structural phase transition” process ... tunable nanostructure to create metamaterials in just one step. The researchers were able to tune the ability to store ...
- What are metamaterials?on August 18, 2020 at 1:09 pm
The core concept of metamaterials is to craft materials by using artificially designed and fabricated structural units to achieve the desired properties and functionalities. These structural units – ...
- Dr. Laura Redmondon October 14, 2018 at 7:59 pm
analysis and testing of novel metamaterials Research Group Website: The research at Clemson Advanced Structures Laboratory (CASL) focuses on creating models for complex material and structural ...
- Akyurtlu Alkimon February 27, 2016 at 6:25 am
(Principal), Barry, C. (Principal) Nanostructured Sensing Elements for Structural Health Surveillance (2010), Grant - Army Research Laboratory Akyurtlu, A. (Co-Principal) Three Dimensional Isotropic ...
The Latest Google Headlines on:
The Latest Bing News on:
Fix the internet
- Pop Culture Fix: “Batwoman” and “Queen Sugar” Preview Their #BlackLivesMatter Storylineson January 25, 2021 at 2:44 pm
Lily Singh explores her impact on the internet, the trailer for Black Lightning season four, the highest paid queer celebs, JoJo Siwa is happier than she's ever been, and more!
- 10 Things to Fix Face Mask Problemson January 25, 2021 at 12:00 pm
From mask chains and filters to extenders and pouches, we've scoured the internet to find hacks that will make mask-wearing more comfortable!
- macOS Apple News bug causing huge background downloads, here’s how to fix iton January 25, 2021 at 6:18 am
This guide with screenshots take a look at how to fix the Apple News download bug in macOS Big Sur that's causing massive background activity.
- Northern internet company secures new satellite to fix shortageon January 25, 2021 at 4:00 am
SSi Canada previously had to stop taking on new customers because of a strain on internet capacity in the fall.
- How To Fix Minecraft Server Connection Timed Out Error On Windowson January 24, 2021 at 9:20 pm
Minecraft was first released in 2021 and still considered to be one of the best selling game since then. Although Minecraft is a solid video game there are instances wherein certain issues can occur ...
- Opinion: To Fix Gaps, New York Must Map Internet Coverageon January 22, 2021 at 8:44 am
The state’s digital divide stems from a lack of data on the availability and cost of high-speed broadband Internet statewide, which is why Gov. Andrew Cuomo should sign the Comprehensive Broadband ...
- NY must map broadband internet coverage so it can fix gaps (Commentary)on January 21, 2021 at 8:09 am
AARP, Public Utility Law Project urge Gov. Andrew Cuomo to sign a bill mandating collection of such data at a deeper level than feds require.
- Web’s inventor says news media bargaining code could break the internet. He’s right — but there’s a fixon January 20, 2021 at 6:43 pm
The code could require Google and Facebook to pay up for simply including links to news articles from other sites. This has never been a requirement on the web.
- The Internet Is a Crime Sceneon January 20, 2021 at 10:56 am
How we conceptualize the role social media played in the Capitol siege will set the stage for information governance across the globe.
- How to Fix ‘Res IEFrame DLL ACR_Error.HRM’ Error in Internet Explorer?on January 18, 2021 at 9:59 am
Some Windows users are reporting that they end up seeing the 'Res IEFrame DLL ACR_Error.HRM' error whenever they attempt to reopen a previously closed ...