Pea-sized robot sets course for pinpoint drug drop inside body
Tiny device could be used to target tumours and ferry high-concentration doses, instruments and cameras
A TINY amphibious robot that can swim through fluids in the body and navigate obstacles to deliver drugs wherever needed has been developed by scientists.
Stanford University has released footage showing its pea-sized millibot jumping over hurdles, leaping through the air before plunging into a tank of water to collect a small piece of cargo.
The wireless cylindrical robot, which is a third of an inch (7.8mm) wide, was shown swimming to an area and depositing its shipment before climbing a small flight of steps out of the tank.
The robot was also tested in a pig stomach, where it was filmed moving easily around ripples of muscle, before reaching an area where it delivered a consignment of blue dye (standing in for liquid medicine) using an internal pump.
Scientists hope that a similar strategy could be used to place high-concentration drugs exactly where they need to be in the body.
When people swallow a drug or have it injected, it spreads throughout the system, which limits how powerful treatments can be. But if a robot can deliver a drug to a precise location, it could allow potent medicines to be deployed where they would do the most good.
Dr Renee Zhao, assistant professor of mechanical engineering at Stanford, said: “This is the most robust and multifunctional untethered robot we have ever developed. It reaches the target, and then releases a high-concentration drug.”
Placing tiny robots in the body is a popular theme in science fiction. In the 1987 comedy Innerspace, Dennis Quaid and a submersible pod were shrunk to microscopic size and injected into a grocery worker.
Similarly, in the 1966 film Fantastic Voyage, a submarine crew were shrunk and placed into the body of an injured scientist to repair his brain.
While over-the-counter pills have cured many ailments for decades, biomedical researchers have only recently begun exploring how to improve targeted drug delivery for more complicated medical conditions such as cardiovascular disease or cancer.
Chemotherapy can be extremely damaging to healthy organs, so finding a way to directly target tumours could radically improve outcomes.
The robot is built from a shell which has been folded into Kresling origami patterns – triangular shapes which have a similar effect as propellers, enabling it to roll, flip and spin when the material is folded or unfolded in specific ways.
It can also squeeze up like an accordion to create a pumping action which allows liquid to be shot out. It can be manoeuvred remotely, using magnetic fields which can be altered in strength and orientation.
A hole in the robot’s centre helps it swim while also providing a suction area to allow cargo, such as pills or liquid medication, to be transported.
The team believe the bot could be used to carry instruments or cameras into the body. They are also hoping to continue to scale down the machine before testing in animals and humans.
The research was published in the journal Nature Communications.