I think it’s safe to assume that Shogo Shimada, a thoracic and cardiac surgeon at the University of Tokyo Hospital, did not start his career thinking he might one day be implanting robots into living animals. Yet that is just what Shimada and a team of surgeons and roboticists from around the world have now achieved.
Their work is the latest in a long line of attempts to solve problems in biology using robots. When I hear about this sort of research, it usually involves micro-robots. And then there’s talk of smaller, nano-size robots that can swim through the bloodstream and deliver drugs or make repairs, as referenced in the 1966 sci-fi film “Fantastic Voyage.”
We’ll return to this in a second, but let’s first examine the problem that Shimada and his colleagues are tackling. Every year, thousands of children are born with defects in some of the tubes in their bodies. For example, a section of the bowel could be missing, or there could be a gap between the esophagus and the stomach. In either case, it’s a serious problem, as food can’t be processed. Shimada was part of a team that implanted a robot into a living pig to fix the problem.
The robot is not the sort of cute android we are used to seeing. It’s a machine made of a couple of steel rings and motors sheathed in waterproof skin. To demonstrate how it can help stimulate growth in an esophagus, it was implanted into a pig’s body and attached to the food pipe.
A computer in the robot very gently controlled the elongation of the steel rings. The experiment showed that the robot caused the esophagus to grow by 77 percent in little more than a week.
I contacted Dana Damian, a roboticist at the University of Sheffield in northern England. Damian is the lead member of the team. I ask her if people might feel squeamish about having robots “living” inside them, but she assuages my concerns.
“Patients already wear implants in their bodies,” Damian says, pointing to hip implants, breast implants and so on. “We want to augment the capabilities of the medical implants.”
This means enabling implants to be able to sense the precise state of the tissue near them, and decide a course of action to guide the repair process.
“In the future, this technology could be used to reconstruct other tubular organs that have been clinically shown to respond to mechanical stimulation,” Damian says, naming organs such as the intestines and the vasculature of the heart. The team’s findings have just been published in the journal Science Robotics.
So it seems this kind of robot will be inside us before even fancier sci-fi versions. However, those are also being developed.
Shuhei Miyashita, who trained at the Tokyo Institute of Technology and is now based at the University of York in the United Kingdom, builds exquisite origami-style robots that can be swallowed. The robot then self-assembles inside the body and can be deployed to patch a wound in the stomach, deliver drugs or retrieve something that’s been swallowed.
Scientists at the Chinese University of Hong Kong in Shatin are using yet another method. They are augmenting living organisms and harnessing them instead of building a micro-robot from scratch. Li Zhang and his colleagues take an algae called spirulina and coat it with metallic nanoparticles. They effectively “robotize” the alga.
The micro-bot is then controlled magnetically. The team found when they tested the robot in a petri dish, that it didn’t harm normal animal cells but destroyed 90 percent of cancer cells. Unexpectedly, the spirulina produces a compound that kills off tumor cells.
And then there’s robo-sperm. Haifeng Xu, based at the Leibniz Institute for Solid State and Materials Research in Germany, managed to fit sperm with microscopic harnesses that can be loaded with drugs. Just like with the spirulina, this allowed the scientists to control the sperm with magnets.
The team want eventually to release the sperm in the reproductive tract of women with cancer. In tests, the sperm swim toward tumors, release their payload of chemotherapy drugs and kill the cancer cells.
We’re not there yet but get ready to become very intimate with robots. As all the scientists involved tend to say when asked about this, “We’re on a fantastic voyage.”
Rowan Hooper is managing editor of New Scientist magazine. He tweets at @rowhoop and his new book, “Superhuman,” is out later this year.
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