Now Microrobots can Propel Themselves Through your Body


As much progress as we’ve made with minuscule micro machines, we’ve long suffered the problem of not being able to propel them through our bodies. Sure, we now have tiny robots capable of targeting cancer cells, manipulate building blocks, etc, but they haven’t been able to actually move, rendering them all but useless.

Until now. At the International Solid State Circuit Conference, engineer Ada Poon, an assistant professor at Stanford, demonstrated a remote controlled micro machine navigating through a liquid, specifically blood. Power was delivered wirelessly. Basically this means that we finally have a method for driving a robot through the blood stream. Says Poon,

“Such devices could revolutionize medical technology, Applications include everything from diagnostics to minimally invasive surgeries.”

In other words, this tech could revolutionize medicine. Imigine, for a moment, that you ave been in a car wreck and there’s internal bleeding. A body with micro robots injected could have the bots maneuver themselves to repair the damage, causing clotting and blocking holes so that the bleeding stops before it is fatal.

Much of Poon’s innovation actually came from the power side of things, thanks to scientists holding to convention. See, scientists have been thinking about getting wireless power to micro robots in the blood stream for 50 years. But the math said it couldn’t be done. Because of how muscles and fat treat wireless signals, high energy, high frequency waves were thought to not be able to penetrate sufficiently to pump in power. And low power, low frequency waves required such a big antenna to receive the power that it wouldn’t fit in most blood vessels. According to the math, common sense said, wireless power in the body couldn’t be done. and because of that, no one really tried.

But Poon realized that the mathematical model they were basing their assumptions on were wrong. Turns out that, instead of treating muscles as if they conduct electricity well, you need to treat them like they are insulators. Do that, and the math suddenly changes. High frequency waves do travel far through the human body. And that all previous research had just been using too low a frequency. Say Poon,

“When we extended things to higher frequencies using a simple model of tissue we realized that the optimal frequency for wireless powering is actually around one gigahertz,” said Poon, “about 100 times higher than previously thought.”

Her findings meant that you don’t need to store power on the devices themselves, allowing them to be drastically shrunk. Suddenly the dream of robotic crafts plying your bloodstream prowling for disease and damage doesn’t seem like such a far fetched idea.

Poon has created two devices for plying through blood. One pumps power into the surrounding blood, creating a small force that pushes the craft along, driven by magnetism. The other relies on the power field itself, switching a magnet back and forth to wiggle along as it is pulled and pushed from the field.

Suddenly, when you get power to the micro machines, whole worlds of new propulsion techniques appear.