Roughly the size of Abraham’s head on a penny is the new “mini sub” that could steer through the body. From Stanford University, Daniel Pivonka and Anatoly Yakovlev built a prototype of such a device. It is tested to be able to wirelessly power and control the prototype by sending radio waves to its two by two millimeter antenna from about two inches away. Without a battery, the device is able to miniaturize itself more than before. The main purpose of this nanotechnology is to deliver drugs or take samples inside the body without cutting it open. By using this device, it can image the GI tract; reducing the cost of cancer screenings.
The science behind this is the magnetohydrodynamic propulsion. Instead of using mechanical propulsion, which is both ineffective and requires battery, the magnetohydrodynamic propulsion takes advantage of an external magnetic field that pushes the device. The magnetohydrodynamic propulsion requires an external magnetic field that creates a Lorentz force on the device’s electrical circuitry. Then, the electrodes send electrical currents through the surrounding fluid that creates a net force to move the device. The patient, of course, has to lie on a magnetic table. With the use of radio waves to tell the prototype how to use its electrodes, the device is now able to successfully move.
With an upward magnetic field, a counterclockwise electrical current will push the device forward and a clockwise current pushes it backwards. By making circuits that create opposing forces on each side, the device is also able to turn left or right.
With the relatively weak magnet, the prototype is only able to move 0.2 inches per second in a dish of saline. If it were in the blood stream, it would need a stronger magnet to overcome the flow. As research continues, the ultimate goal would be to do complicated tasks such as cleaning out your arteries or even perform surgeries from the inside.