Infiltrating, Navigating the Human Body

"The array of behaviours and capabilities is certainly impressive and sets this robot apart from most others."

"These critters are very cute!. Love how the authors put the little guy through mini-obstacle courses."

"My other thought is that the pilot, who we don’t see, is also quite impressive. Clearly whoever is controlling the magnetic fields has gained some hard-earned intuition and fine skills based on a lot of experience and trial-and-error."
Leif Ristroph, mathematician, Courant Institute, New York University

"Our robot is made of an elastomer rubber, which is filled with many magnetic, small particles. We program the magnetic properties of these particles so that from outside, when we apply a magnetic field, the elastic sheath-shaped robot changes its shape to anything we want."
"Then it does different motions. When you look at this tiny thing crawling and jumping, it looks like a creature."
"The robots already are small enough for our digestive system and urinary systems. We'd like to go smaller, even down to tens of microns, so that we can reach almost anywhere inside your body."
"It can navigate across solid, partially or fully water-filled terrains. Such solid terrains can be fully rigid or soft."
 "Drugs can be targeted to a specific location inside our body and delivered in more controlled doses, which could make the drug delivery more efficient and minimize the drug side effects. [And because the robots are so small and soft], they can’t damage any tissue they are interacting with."
Metin Sitti, head, physical intelligence department, Max Planck Institute for Intelligent Systems, Stuttgart Germany

The tiny robot pictured with a coin to scale. Max Planck Institute for Intelligent Systems

It is a tiny object. Purpose-designed by engineers in Germany to be enabled to move within the human stomach or urinary system. Seeing it, one could be forgiven for mistaking it for an insignificant piece of plastic, inanimate, uninteresting. Until it begins moving. For this tiny strip of material is actually a centimeter-long robot with a rubbery appearance. And this robot can walk, jump, crawl, roll -- even swim; a wonder to behold. It is a prototype of a robot that the engineers whose study was recently published in the journal Nature, plan to make infinitesimally smaller, capable of entering the most constricted areas of the human body.

To see it is to marvel at the human ingenuity that could construct this tiny worm-like robot that can walk, roll and jump. A soft, tiny worm that can even skid along the surface of water. Its purpose, however, is not to entertain, but eventually to deliver targeted drugs around the human body. The engineers who pitted their expertise and brains to emulate nature found inspiration in soft-bodied creatures such as larvae, roundworms, jellyfish and caterpillars -- all of which are endowed with the capacity to navigate complex surfaces easily; wet, dry, rough, smooth.

The robot has no legs; like a worm or a snake, its body moves through repetitive undulating motion. And using that motion, it is capable of climbing out of a pool of water, to move from that wet environment toward a dry one. The most unusual aspect of this robot, apart from its minimalist appearance and moving features emulating a natural creature in a variety of backgrounds, is its "motion possibilities to navigate in complex environments", explains Dr. Sitti who supervised the project.

The most immediate goal is to place the minuscule robot into a digestive system or urinary system -- eventually the vascular system -- to enable it to navigate across all these complex tissues. Currently in the realm of purpose-designed, usefully invasive medical devices are catheters, a millimeter in diameter representing the only available tools, tethered for retrieval purposes. The goal with this tiny robot is to access difficult-to reach areas in the body with minimal invasion.

To explore its full potential -- the function of drug delivery -- loading a cargo into the robot which it could deliver by the shape of the robot opening to discharge its cargo is the eventual goal. Alternately, producing a robot with a small pocket opening only on 'instruction' with an especial shape change that could be controlled by the transmission of an order, is another option.

A fully biodegradable version of the robot is envisioned. So that, when its function has completed its purpose, the robot could dissolve within the body leaving no side effects, no toxicity and no foreign material to cause irritation or any other issues within the body.