Why you should care
The future of medicine? Miniature robots communicating with doctors from inside our bodies.
This OZY original series brings to you Medical Breakthroughs – and the people behind them – that could change how doctors treat us, find fixes to today’s diseases and make our lives truly better.
David Zarrouk carefully places the tiny robot into a cleaned-up pig intestine on his table, and flips on the switch. About the size of a thumb, the miniature robot comes to life and starts worming through the intestine, all the way through the other end. The researcher at Ben-Gurion University in Israel draws his inspiration from the 1960s movie Fantastic Voyage. There, a shrunken submarine swims through a scientist’s bloodstream to repair his brain. Zarrouk hopes to turn what he saw on the screen into reality. “You can call it a gut bot,” he says. He isn’t alone.
Since the turn of the century, scientists have eyed implantable medical devices or particles, sometimes as tiny as ingestible pills, as a long-awaited solution that could allow them to monitor body functions from the outside while avoiding painful, and at times costly, surgeries. But now, researchers are leapfrogging those implants, instead developing minuscule robots that are emerging as the next frontier in medical science.
Until this decade, there were about 10 labs globally that were trying to develop such robots. Today, most of those efforts have advanced to a stage where they’re no longer science fiction, and the field is taking off as a major industry of the future. More than two dozen labs — from China to Canada and Israel to Italy, and at other research institutions across the U.S. and Europe — have now published research on their nanobot projects. And a June 2018 report by Market Research Future estimates that the medical nanobots industry will grow annually at 21 percent to reach $100 billion — the size of Morocco’s entire economy — by 2023.
Unlike implantable devices that stay where they are placed, these robots are mobile and can be directed by outside human operators or even move around with some autonomy. This mobility lets them carry out diagnostics, organ repair and even perform surgeries from the inside, reducing the extent to which tissues need to be cut.
They can be delivering drugs to organs, continuously gather information or do localized treatments …
Hod Lipson, roboticist, Columbia University’s Creative Machines Lab
Scientists at the University of California, San Diego have built nanobots that are able to swim in the blood and fight superbugs like MRSA — methicillin-resistant Staphylococcus aureus — that attack both red blood cells and platelets. At Northwestern University, materials science and engineering professor John Rogers and his team are taking that next step: thinking about the future of robots after they’re done with their work. They’re building electronics that can safely dissolve within the human body once they complete their mission, similar to how sutures work.
And at Ben-Gurion University, Zarrouk is refining his gut bot to one day replace costly and uncomfortable intestinal diagnostic procedures in which doctors push a camera-equipped tube down a patient’s throat and into the stomach — to look for ulcers, polyps or tumors.
“These advancements can really create a lot of impact,” says roboticist Hod Lipson, who directs Columbia University’s Creative Machines Lab. “They can be delivering drugs to organs, continuously gather information or do localized treatments where you need to open up a particular artery inside.”
These emerging breakthroughs need to pass multiple trials and regulations before they become available in the medical market — they’re all at the laboratory stage at the moment. And even in the laboratory, the step up from stationary, implanted electronics to robots that swim through body fluids and blood isn’t straightforward. To make his bot fully functional, Zarrouk needs to shrink its current size by half, so it can fit inside a small capsule. Patients could then consume it, and doctors holding joysticks could direct its movement within the body. The gut bot would traverse the intestines, transmit the information from the inside and finally leave the body in “a natural way,” with excreta.
But researchers are convinced these swimming bots are the future of ingested medical electronics. The enemy for the researchers at UCSD, for instance, is a tricky customer, and it needs cutting-edge solutions like the one they’re developing to truly beat it, say scientists.
MRSA mounts a double attack on the human body: The bacteria attach to and destroy blood platelets, the cells that prevent bleeding, and simultaneously release toxins that punch holes in red blood cells, damaging their ability to fight pathogens. So researchers built their nanobots as decoys. The team covered tiny gold nanowires with a biological coating that looks like the outer membranes of platelets and red blood cells. Then the team used ultrasound waves to propel the bots, each 25 times smaller than the width of a human hair, through blood samples. As the nanobots floated around posing as MRSA’s targets, they essentially “fished out” the invaders and disarmed them. After five minutes, blood samples treated with mobile nanobots had three times less bacteria and toxins than samples with no treatment.
“The ability to move within the bloodstream was a key factor,” says the study’s co-author, Berta Esteban-Fernández de Ávila, highlighting why stationary implants couldn’t have done the job. “When robots are moving through the blood sample, they are increasing the contacts with bacteria and toxins, so they work faster, and achieve a higher detoxification efficiency.” The team is now moving onto testing this process in mice.
At Northwestern University, Rogers and his team are trying to turn what electronics engineers have tried to do for decades on its head. “The goal of the electronics industry has always been to build durable devices that last forever,” Rogers says — but you can also do the opposite. With the right choice of materials, electronics can be made biodegradable and compatible with the human body.
Rogers noticed that when silicon, commonly found in electronics, is used in very thin sheets, it can dissolve in water. Once that silicon “wrapper” is gone, the electronic parts inside it can decompose too. Moreover, these parts can be made from metals that the human body uses naturally and actually needs — such as magnesium, zinc or iron. They can be absorbed without harm. Working with physicians, Rogers’ team has built several variations of such “transient electronics,” including a temporary pacemaker and a device that electrically stimulates bone growth. And by using silicon sheets of different thicknesses, these devices can be programmed to last a specific period of time. Rogers’ transient electronics are already being tested in mice.
“We are learning how to make and control these kinds of microscale machines,” says Lipson. “It’s exciting.” Transformative too. When a young Zarrouk watched the film that would half a century later lead him to design his gut bot, it was pure science fiction. “Now it’s no longer fiction. It’s just science,” says Zarrouk. And it’s the future.