This 940 µm medgadget one day could be used for minimally invasive surgery or as a drug delivery device. Designed for in situ operation, the device is magnetically controlled: tune the magnetic frequency of the external field to 2 kilohertz and you will vibrate a motor that controls a small syringe; tune to 3 kilohertz and you are driving a pump that injects drugs into the vessel. Moreover, the device can be introduced into blood, for a body voyage, Asimov style. From the Discovery Channel article:
A new microscopic robot that is so small it can be injected into the body through a syringe could one day be used by doctors to analyze medical conditions, deliver drugs or perform minimally invasive surgery.
The biomedical micro-robotic system, developed by a team of scientists from the Swiss Federal Institute of Technology in Zurich, Switzerland, is the smallest of its kind with machined and assembled parts, and has been demonstrated to successfully maneuver through a watery maze using external energy from magnetic forces.
The minimally invasive robot is particularly well-suited to navigate through the blood vessels of the heart or the fluids located behind the eye and in the ear to diagnose and treat disease, resulting in less injury and a faster recovery time for patients.
“The application we’re actively considering is eye surgery in which these devices are guided inside the eye toward the retina by a surgeon to inject drugs in retinal veins that are about the size of a human hair,” said team leader Brad Nelson, professor of robotics and intelligent systems.