The Massachusetts Institute of Technology has done a lot of important scientific work over the years, and you can add another discovery to the pile: researchers at MIT have created new 3D printed structures that can “remember” their shapes, even after they are stretched and bent to oblivion, which could lead to breakthroughs in solar cells and drug capsules that release medicine only when a fever is detected.

In cooperation with the Sinapore University of Technology and Design, the MIT researchers found a way to print tiny features on a micron scale, and then bent them — causing them to spring back into their original shape afterwards after being heated to a certain temperatures, according to an MIT statement.

There are so many potential important applications for the discovery, including actuators that would turn solar panels toward the sun automatically and drug capsules that act on their own. It’s something that goes beyond 3D printing into what researchers would call 4D printing, as the structures cross into the fourth dimension of time.

Nicholas X. Fang, associate professor of mechanical engineering at MIT, said in the statement that shape-memory polymers are able to morph in response to temperature, which allows for the previously mentioned practical applications.

“We ultimately want to use body temperature as a trigger,” Fang said. “If we can design these polymers properly, we may be able to form a drug delivery device that will only release medicine at the sign of a fever.”

Former MIT-SUTD research fellow Qi “Kevin” Ge, a fellow researcher on the project, explained how 4D printing is significantly different from typical 3D printing.

“Our method not only enables 4-D printing at the micron-scale, but also suggests recipes to print shape-memory polymers that can be stretched 10 times larger than those printed by commercial 3-D printers,” Ge said. “This will advance 4-D printing into a wide variety of practical applications, including biomedical devices, deployable aerospace structures, and shape-changing photovoltaic solar cells.”

Basically, Fang and other researchers have been looking into using soft, active materials as tools, including shape-memory polymers. This has implications for use in biomedical devices, soft robotics, wearable sensors and artificial muscles, the authors wrote, describing the polymers as “particularly intriguing,” as they can switch between two states: a harder state at lower temperatures and a softer state at higher temperatures.

“The reality is that, if you’re able to make it to much smaller dimensions, these materials can actually respond very quickly, within seconds,” Fang said. “For example, a flower can release pollen in milliseconds. It can only do that because its actuation mechanisms are at the micron scale.”