Doctors are often faced with the challenge of performing microsurgery to repair blood vessels, transplant tissue or reattach a severed limb. These procedures are very intricate, and surgery is often not the most effective solution since it can be very invasive and difficult to conduct. Soon, many surgeons could be turning to nanotechnology and performing delicate tasks by remotely controlling tiny robots, similar in size to a grain of rice, that could travel through the body.
At Tohuku University in Japan, electrical engineer Kazushi Ishiyama and his group have designed tiny spinning screws that can swim through veins in the body. They can potentially burrow into tumours to kill them or deliver drugs to a specific tissue or organ. Since they are so small, they could be injected into the body using a standard hypodermic needle and once inside, could be magnetically steered around the body using a 3D magnetic field supply and controller. Ishiyama believes that these devices will be particularly useful for removing brain tumours since they are difficult to operate on.
Instead of relying on a magnetic field, other researchers are creating microrobots powered by tiny motors that could swim through the body and help with diagnosing and treating certain conditions. Dr. James Friend and a team of mechanical engineers at Monash University in Australia have already built a liner motor the size of a salt crystal, but are now working to create an even smaller one the width of two human hairs.. Its propulsion mechanism is similar to what the bacteria E. coli uses to swim through the body. A rotating motor whirls the flagella around its axis, much like a stockwhip, and if it is in a liquid, it screws its way through the fluid. "Imagine a pizza maker who takes a round ball of dough and, as he throws it into the air, he spins it so it turns into a helical motion. Well, our motor does the same thing, except it spins 100,000 times a second," says Friend.