Clever Design For Drug Delivery: Sperm-Shaped “Brobots”

Welcome MagnetoSperm, microscopic robots controlled by magnetic fields and inspired by the workaday sperm cell.

As for android babies, well, this new class of microrobots called MagnetoSperm probably won’t be used to impregnate you. (You never know what the future holds.) But these tiny sperm-shaped robots could in fact help with in vitro fertilization (IVF) one day, when they’re not delivering your drugs, sorting your cells, cleaning your clogged arteries, or performing other surgical procedures.


“It’s a bio-inspired design,” lead researcher Sarthak Misra, from the University of Twente in the Netherlands, tells Co.Design. “We knew that in nature there exist these sperm cells that move by oscillating a single long tail. So then we thought, if we had a small magnetic head and a long tail and provided an oscillating magnetic field, we might be able to move this thing through the human body to hard-to-reach areas.”

The “brobots,” as one scientific journal is gleefully calling them, were made by spin-coating a five-micron layer of polymer onto a silicon support wafer. A 200-nanometer layer of cobalt-nickel coats their “heads,” which lets them respond to magnetic fields. This means they don’t need any internal navigation system, so they’re even smaller than most existing microrobots. When they’re exposed to an oscillating magnetic field–as weak as that exerted by a refrigerator magnet–their little tails start waggling, and they can be guided towards their destination.

At 322 microns long, 5.2 micrometers wide and 42 micrometers thick, they’re roughly six times the size of actual human sperm–but they mimic their tadpole-like shape as well as their motion. Misra is currently trying to make the nano-bots even smaller, and is trying to improve on the design to make it biodegradable and biocompatible, so it will flush naturally out of the human body.

“We want to make minimally invasive surgery even less invasive,” Misra says. He envisions these nano-bots being injected close to a deviant region, and then precisely guided to specific cells or areas. “It could perform a biopsy, or eat up tissue at a specific location by oscillating fast, or deliver drugs by being coated in chemicals.” It might take up to 10 to 15 years before these tiny sperm-like bots are developed enough to start swimming around in human bodies–but they could be used in IVF studies in half that time, Misra says. (Meanwhile, we can still experiment with sperm itself.)

Admittedly, we were disappointed when we realized MagnetoSperm wasn’t designed to help our favorite bots, like Wall-E and Eva, procreate. But never say never. Maybe fertile androids are in our future.

About the author

Carey Dunne is a Brooklyn-based writer covering art and design. Follow her on Twitter.