Select your localized edition:

Close ×

More Ways to Connect

Discover one of our 28 local entrepreneurial communities »

Be the first to know as we launch in new countries and markets around the globe.

Interested in bringing MIT Technology Review to your local market?

MIT Technology ReviewMIT Technology Review - logo

 

Unsupported browser: Your browser does not meet modern web standards. See how it scores »

Over the last 10 years, thousands of troops have returned from Iraq and Afghanistan with traumatic brain injuries triggered by blasts from improvised explosive devices. Growing evidence suggests that the shockwaves produced by these explosions lead to injuries that are different from concussions suffered in car accidents and football games—and that even seemingly minor blasts, from which a soldier might walk away apparently unharmed, could damage the brain, especially with repeated exposure.

A new device being developed by researchers at the University of Pennsylvania School of Medicine could provide a simple way to measure the magnitude of explosions to which a soldier is exposed over time. It could also help scientists better understand the threshold for brain injury.

“Soldiers [with mild traumatic brain injury] can often appear normal, so it’s critically important to have some kind of objective measure to denote which soldiers have been exposed to a blast that is powerful enough to cause brain injury,” says Kacy Cullen, assistant professor of neurosurgery at Penn and leader of the study. “These devices wouldn’t diagnose brain injury, but they would indicate who needs a more thorough workup, and could influence decisions about when a soldier can return to action.”

The powerful blasts triggered by improvised explosive devices generate a supersonic wave followed by another shock wave called an overpressure wave. These forces are often strong enough to throw someone in the air, triggering the kind of blunt impact one might experience in a car accident. But many scientists believe that the waves themselves, in addition to the impact, can damage the brain.

The military has amped up efforts to measure the specific properties of explosions using helmet-mounted accelerometers and pressure sensors, but these devices have drawbacks. “They can be expensive, cumbersome, and require power to operate,” says Cullen. “Ours is a materials-based indicator, so you don’t need an internal power supply; the power from the blast induces the color change.”

As with a butterfly’s wing, the color of the material used in the detector is determined by its structure rather than chemical composition or pigment. It contains photonic crystals made up of layers of pores separated by columns a few hundred nanometers in width—the size of the pores and columns and how they are arranged within the structure determines the color of the sensor. When exposed to a shockwave, the columns collapse, either changing the color of the material or making it lose color altogether.

0 comments about this story. Start the discussion »

Credits: Yongan Xu and Shu Yang, Douglas H. Smith, University of Pennsylvania School of Medicine

Tagged: Biomedicine, materials, TBI, traumatic brain injury, lithography, blast event, explosion

Reprints and Permissions | Send feedback to the editor

From the Archives

Close

Introducing MIT Technology Review Insider.

Already a Magazine subscriber?

You're automatically an Insider. It's easy to activate or upgrade your account.

Activate Your Account

Become an Insider

It's the new way to subscribe. Get even more of the tech news, research, and discoveries you crave.

Sign Up

Learn More

Find out why MIT Technology Review Insider is for you and explore your options.

Show Me
×

A Place of Inspiration

Understand the technologies that are changing business and driving the new global economy.

September 23-25, 2014
Register »