Nav: Home

The stiffest porous lightweight materials ever

December 12, 2018

3D printing and other additive production techniques make it possible to manufacture materials with internal structures of previously unimaginable complexity. This is interesting for lightweight construction, too, as it enables the development of materials that have the highest possible share of interior voids (to make the materials as light as possible) but are simultaneously as robust as possible. Achieving this requires that the internal structures be intelligently organised for maximum efficiency.

A research team from ETH Zurich and MIT led by Dirk Mohr, Professor of Computational Modeling of Materials in Manufacturing, has developed and fabricated material architectures that are equally strong in all three dimensions, and that are simultaneously extremely stiff.

It is possible to determine mathematically just how stiff materials with internal voids can theoretically become; Mohr's structures have been shown to come extremely close to this theoretical maximum stiffness. Put another way, it's practically impossible to develop other material structures that are stiffer for the given weight.

Plates replacing trusses

A characteristic feature of the design is that the stiffness in the material's interior is achieved through plate-lattices rather than trusses.

"The truss principle is very old; it has long been used for half-timbered houses, steel bridges and steel towers, such as the Eiffel Tower. We can see through truss lattices, so they are often perceived as ideal lightweight structures," says Professor Mohr. "However, using computer calculations, theory and experimental measurements, we have now established a new family of plate-lattice structures that are up to three times stiffer than truss-lattices of the same weight and volume." And it is not just the stiffness (resistance to elastic deformation) of these structures that approaches theoretical maximum values: their strength (resistance to irreversible deformation) does, too.

The ETH researchers initially developed these lattices on the computer, calculating their properties in the process. Then they produced them at the micrometre scale from plastic through 3D printing. Mohr emphasises, however, that the advantages of this design are universally applicable - for all constituent materials and also on all length scales, from the very small (nanometre-sized) to the very large.

Ahead of their time

Mohr and his research team are ahead of their time with these new lattices: at present, manufacturing with 3D printing is still relatively expensive. "If these kinds of lattices were to be additively manufactured from stainless steel today, they would cost as much per gram as silver," says Mohr. "But the breakthrough will come when additive manufacturing technologies are ready for mass production. Lightweight construction, the current cost of which limits its practical use to aircraft manufacturing and space applications, could then also be used for a wide array of applications in which weight plays a role." In addition to making structures lighter, the numerous voids also reduce the amount of raw materials needed, and thus also the material costs.

There's no limit to the potential applications, Mohr says. Medical implants, laptop casings and ultralight vehicle structures are just three of many possible examples. "When the time is right, as soon as lightweight materials are being manufactured on a large scale," Mohr says, "these periodic plate lattices will be the design of choice."
-end-
Reference

Tancogne-Dejean T, Diamantopoulou M, Gorji MB, Bonatti C, Mohr D: 3D Plate-Lattices: An Emerging Class of Low-Density Metamaterial Exhibiting Optimal Isotropic Stiffness. Advanced Materials 2018, 30: 1803334, doi: 10.1002/adma.201803334 [http://dx.doi.org/10.1002/adma.201803334]

ETH Zurich

Related Manufacturing Articles:

Highest throughput 3D printer is the future of manufacturing
Northwestern University researchers have developed a new, futuristic 3D printer that is so big and so fast it can print an object the size of an adult human in just a couple of hours.
A new manufacturing process for aluminum alloys
Using a novel Solid Phase Processing approach, a research team at Pacific Northwest National Laboratory eliminated several steps that are required during conventional extrusion processing of aluminum alloy powders, while also achieving a significant increase in product ductility.
Researchers develop new lens manufacturing technique
Researchers from Washington State University and Ohio State University have developed a low-cost, easy way to make custom lenses that could help manufacturers avoid the expensive molds required for optical manufacturing.
Nanocrystal 'factory' could revolutionize quantum dot manufacturing
A new system for synthesizing quantum dots across the entire spectrum of visible light drastically reduces manufacturing costs, can be tuned on demand to any color and allows for real-time process monitoring to ensure quality control.
NIST: Blockchain provides security, traceability for smart manufacturing
Engineers at the National Institute of Standards and Technology (NIST) needed a way to secure smart manufacturing systems using the digital thread , so they turned to the new kid on the block ... blockchain, that is.
Microbial manufacturing
Led by Emily Balskus, Professor of Chemistry and Chemical Biology, a team of researchers has untangled how bacteria found in soil are able to manufacture streptozotocin, showing for the first time that the compound is produced through an enzymatic pathway and revealing the novel chemistry that drives the process.
Research to improve welding process for manufacturing industries
New research, led by the University of Leicester, will optimise the welding and additive and manufacturing process
Near-infrared spectroscopy could improve flu vaccine manufacturing
Recent research outlines how near-infrared spectroscopy could be used to make cell-culture-based flu vaccine manufacturing faster and more efficient.
New technology improves hydrogen manufacturing
INL researchers demonstrated high-performance electrochemical hydrogen production at a lower temperature than had been possible before.
Atomic-scale manufacturing now a reality
Scientists at the University of Alberta have applied a machine learning technique using artificial intelligence to perfect and automate atomic-scale manufacturing, something which has never been done before.
More Manufacturing News and Manufacturing Current Events

Top Science Podcasts

We have hand picked the top science podcasts of 2019.
Now Playing: TED Radio Hour

In & Out Of Love
We think of love as a mysterious, unknowable force. Something that happens to us. But what if we could control it? This hour, TED speakers on whether we can decide to fall in — and out of — love. Guests include writer Mandy Len Catron, biological anthropologist Helen Fisher, musician Dessa, One Love CEO Katie Hood, and psychologist Guy Winch.
Now Playing: Science for the People

#543 Give a Nerd a Gift
Yup, you guessed it... it's Science for the People's annual holiday episode that helps you figure out what sciency books and gifts to get that special nerd on your list. Or maybe you're looking to build up your reading list for the holiday break and a geeky Christmas sweater to wear to an upcoming party. Returning are pop-science power-readers John Dupuis and Joanne Manaster to dish on the best science books they read this past year. And Rachelle Saunders and Bethany Brookshire squee in delight over some truly delightful science-themed non-book objects for those whose bookshelves are already full. Since...
Now Playing: Radiolab

An Announcement from Radiolab