In this video excerpt from NOVA’s "Making Stuff: Smaller", host and New York Times technology columnist David Pogue visits the Institute of Robotics at ETH Zurich, where materials scientists are designing a microbot—about the width of a strand of hair—that can travel into a human eye to treat a type of blindness. The microbot is controlled by an externally generated electromagnetic field, eliminating the need for bulky mechanical parts. In a related activity, students learn about magnets and their properties while designing their own model of a small magnet-powered robot. Students also see how materials scientists use design ideas from nature to overcome weird forces that microbots encounter.
Making Stuff Smaller Activity (Document)
What Is Materials Science? (Document)
DAVID POGUE But in the world of microscopic medicine, the story of smaller is unfolding on a vastly accelerated timeframe.
In fact, scientists are on the verge of realizing a 21st century version of the Fantastic Voyage story. They are developing microscopically small robots that travel into the body's deepest reaches to diagnose, treat, and even destroy deadly illnesses.
This is your lab?
BRAD NELSON This is my lab.
DAVID POGUE This is where you build your robots?
BRAD NELSON This is where we build the robots.
DAVID POGUE This is Brad Nelson. He's created a robot that could help cure blindness.
Oh, nice, it's incredibly lifelike.
BRAD NELSON Yeah, that's a mannequin.
DAVID POGUE Oh, sorry.
BRAD NELSON These are the ones we build.
DAVID POGUE What? That's a robot?
BRAD NELSON That's a robot.
DAVID POGUE Looks like a splinter.
BRAD NELSON Well, this is a microrobot. We use them to help perform surgeries on the eye or inside of the eye.
DAVID POGUE The device is only a hundredth of an inch wide, small enough to fit into the needle of a syringe, like the tiny sub in Fantastic Voyage. But the similarity ends there.
This unmanned device is designed to treat a type of blindness caused by blocked blood vessels in the retina, the tissue where images are formed. The robot delivers an extremely small dose of medicine to restore blood flow and vision.
That makes me think that this little tiny thing has batteries and little propellers and some kind of knowledge to know where to go in the eye. I have a hard time believing that.
BRAD NELSON That's right. The way we energize is we use externally generated electromagnetic fields. So, basically, it's a magnet.
DAVID POGUE To make the device small enough, Brad had to abandon the idea that robots have to be mechanical. Instead, he focused on finding a material that would let him eliminate bulky moving parts.
He chose two elements, samarium and cobalt. Combined, they form a material highly sensitive to magnetic fields, which means that Brad can direct the movement of the robot without touching it.
Once again, a material replaces a machine and the device gets smaller.
BRAD NELSON So then, besides just the robot, what we also have is this system here, of electromagnets, and so what each of these copper coils do, is they generate magnetic fields.
DAVID POGUE Oh, man. Yeah, you got a bunch of them in every direction.
BRAD NELSON So we have eight of these here. That's why we call this the OctoMag.
DAVID POGUE OctoMag?
BRAD NELSON That's right.
DAVID POGUE The OctoMag. By adjusting the strength of these eight electromagnets, the surgeon can move the microrobot any direction along the x, y and z-axes, pushing or pulling it through the eye.