Ever since the blockbuster movie “Fantastic Voyage,” we’ve been intrigued by the idea of sending a microscopic mobile device into the human body to perform specific tasks. It could move around on its own, without a tether, to deliver payloads or grab biopsy samples or a range of other useful missions.
One of the newest approaches in this area comes from researchers at the City University of Hong Kong. A team there has developed a tiny soft robot that can “walk” inside a patient’s body. It relies on a top layer to which a large number of soft legs are attached, each about 1 mm long. Some say it resembles a caterpillar. By deforming the top layer, the device can raise and lower sections of its “body” which in turn causes the legs to propel it forward. It can reach 10 times higher than its leg length, as demonstrated in the video linked above where the robot climbs over tall barriers. Magnetic particles in the top layer allow the movement to be controlled remotely using electromagnetic fields.
“The rubbery piece is soft and can be cut easily to form robots of various shapes and sizes,” according to Professor Wang Kuanki. The multi-leg design reduces friction, and are designed to work in wet and dry environments. What’s more, it can carry a load that is 100 times its own weight. This means that it can deliver a significant payload, such as a drug, to a very specific location, such as a cancer tumor.
It will still be years before this becomes a useful tool for treating humans. The research team wants to find biodegradable materials so that the robot could simply dissolve after completing its mission. It could become a useful tool in time, and may cause us to rethink what we mean by “non-invasive” measures.