Imagine tiny robots that are so small they could travel through your bloodstream to deliver medicine exactly where it’s needed or find leaks in gas pipelines without anyone having to dig up the ground.
Engineers at MIT have taken a big step toward making this a reality by designing an incredibly small battery that could power these cell-sized robots.
The battery is just 0.1 millimeters long and 0.002 millimeters thick—about the same thickness as a human hair.
Despite its tiny size, it can generate enough power to operate a small electronic circuit, sensor, or even a tiny mechanical arm.
The secret to this power lies in the way the battery works: it captures oxygen from the air and uses it to oxidize zinc, creating an electric current of up to 1 volt.
Michael Strano, a professor of chemical engineering at MIT and the senior author of the study, believes this new battery will be a game-changer for tiny robotics. “We think this is going to be very enabling for robotics,” Strano said.
“We’re building robotic functions onto the battery and starting to put these components together into devices.”
The study, led by Ge Zhang, Ph.D., and Sungyun Yang, an MIT graduate student, was published in the journal Science Robotics.
For years, Strano’s lab has been working on tiny robots that can sense and respond to their environment.
One of the biggest challenges has been figuring out how to power these robots. While some researchers have used solar power to run small devices, this method requires the robots to have a light source pointed at them constantly.
This limits their ability to move freely, making them like “marionettes” controlled by an external source.
To give these tiny robots more independence, Strano’s team decided to create a battery that could be embedded inside the robot itself. They chose a type of battery known as a zinc-air battery, commonly used in hearing aids because of its long lifespan and high energy density.
The battery is made from a zinc electrode connected to a platinum electrode, all embedded in a polymer called SU-8, which is often used in microelectronics. When the battery is exposed to air, the zinc reacts with oxygen, releasing electrons that flow to the platinum electrode, generating a current.
In their study, the researchers demonstrated that this tiny battery could power a small robotic arm, a memory storage device, and a clock circuit that helps robotic devices keep track of time. The battery could also run two different sensors that change their electrical resistance when they come into contact with certain chemicals.
Although the battery was connected to external devices with a wire in this study, the researchers plan to integrate it directly into future robots. “This is going to form the core of a lot of our robotic efforts,” Strano explained. “You can build a robot around an energy source, just like you can build an electric car around the battery.”
One exciting potential use for these tiny robots is in medicine. The researchers imagine creating robots that could be injected into the human body, where they could deliver drugs like insulin directly to specific sites. These robots would be made from materials that are safe for the body and would break down once their job is done.
The team is also working on boosting the battery’s voltage, which could open the door to even more applications for these tiny robots, from healthcare to industrial tasks.
Source: MIT.
