Nobody is yet plotting to shrink Raquel Welch and inject her into your veins, but engineers are making notable progress toward the Fantastic Voyage vision: creating miniature probes that could dart around in your blood and treat disease from the inside.
This past year, mechanical engineer James Friend of Monash University in Australia crafted a robot motor just a quarter of a millimeter in diameter and 2 millimeters long, smaller than the head of a pin. It is built out of piezoelectric materials that vibrate when exposed to an electric field. Those vibrations can be converted into rotary motion to propel a miniature swimming robot. Inserted into a patient, such a device could transport catheters and guide wires, carry a camera, or deliver drugs to the site of an injury. “It will increase the ability of the doctor to see and control what is happening during surgery,” Friend says. His group is testing the mini-motor in silicone models of human arteries and planning even smaller versions.
Meanwhile, engineers at Technion, the Israel Institute of Technology, debuted Virob (video), a buglike microbot that needs no internal power source. Instead, a magnetic field outside the body induces vibrations in its legs, propelling it forward. The Technion team hopes to deploy Virob into the ears of people suffering from hearing loss, stimulating nerve cells that lie beyond the reach of cochlear implants.
More recently, Italian researchers developed an robotic "spider pill" that a patient swallows and then extends its eights legs after it arrives in the intestines. Doctors remotely deploy the bot to check for polyps and tumors; it sends back images taken with its tiny camera. The spider pill comes out with the rest of the digestive tract's contents once its (ahem) duty is done.
