Skip to Content
77 Mass Ave

Flexible diamonds

Brittle material is bendable in tiny needle form.
Courtesy of the researchers

Diamond is well known to be the strongest of all natural materials, but that strength comes at a price: brittleness. So an international team of researchers from MIT, Hong Kong, Singapore, and Korea was surprised to discover that when grown in extremely tiny, needle--like shapes, diamond can bend and stretch, much like rubber, and snap back to its original shape.

The team showed that narrow diamond needles, similar in shape to the rubber tips on the end of some toothbrushes but just a few hundred nanometers across, could flex and stretch by as much as 9 percent without breaking and then return to their original configuration. Ordinary diamond in macroscopic form stretches much less than 1 percent.

Putting crystalline materials such as diamond under very large elastic strains, as happens when these pieces flex, can change their mechanical, thermal, optical, magnetic, electrical, electronic, and chemical reaction properties in significant ways. The process could be used to design materials for specific applications through what’s known as “elastic strain engineering,” the team says.

The diamond needles, which were grown through a chemical vapor deposition process and then etched to their final shape, were observed in a scanning electron microscope while being pressed with a standard diamond-tip “nanoindenter.” The team also did simulations to interpret the results and was able to determine precisely how much stress and strain the needles could accommodate.

The unexpected find was reported this year in Science by senior author Ming Dao, a principal research scientist in MIT’s Department of Materials Science and Engineering. He says the results could open the door to a variety of diamond-based devices for applications such as sensing, data storage, actuation, biocompatible in vivo imaging, optoelectronics, and drug delivery. For example, diamond has been explored for delivering drugs into cancer cells, and if the tips are flexible, they could be more resistant to breakage. 

Keep Reading

Most Popular

A view of clouds illuminated by sunlight
A view of clouds illuminated by sunlight

We can’t afford to stop solar geoengineering research

It is the wrong time to take this strategy for combating climate change off the table.

conceptual illustration showing various women's faces being scanned
conceptual illustration showing various women's faces being scanned

A horrifying new AI app swaps women into porn videos with a click

Deepfake researchers have long feared the day this would arrive.

Death and Jeff Bezos
Death and Jeff Bezos

Meet Altos Labs, Silicon Valley’s latest wild bet on living forever

Funders of a deep-pocketed new "rejuvenation" startup are said to include Jeff Bezos and Yuri Milner.

ai learning to multitask concept
ai learning to multitask concept

Meta’s new learning algorithm can teach AI to multi-task

The single technique for teaching neural networks multiple skills is a step towards general-purpose AI.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.