In the 1966 film “Fantastic Voyage,” a team of intrepid CIA agents and doctors boarded a submarine. They were miniaturized, then injected into a fellow CIA agent’s bloodstream.

The goal? To remove a blood clot threatening the agent’s life.

Today, scientists are trying to develop something eerily similar: microscopic vehicles to deliver medications within the human body.

These medications are part of a field of treatment called nanomedicine, which aims to treat disease at its heart. Using nanomedicine could cut down both on the amount of medication a person needs and any side effects the medication may have.

But one of the field’s challenges is getting these medications to where they need to be. One solution is building structures small enough to swim through fluids found in an environment such as the human body.

A team of German and Israeli scientists published a paper in the journal A-C-S Nano that demonstrates their success in building a corkscrew-shaped propeller made of silica and nickel. This tiny structure is 400 nanometers long and 70 nanometers in diameter. By comparison, a period that dots the end of a sentence is 1 million nanometers wide.

To test the propeller’s ability to move through the human body, the scientists swam it through a fluid called hyaluronan (hi-al-yur-uh-nann), the same substance found in a person’s eyeball. The scientists were able to control the propeller using a magnetic field.

Although this fluid contains strands of protein that could trip up a propeller, this particular one is small enough to slip through them. In fact, its super-small size allowed it to move even more quickly than expected. Next, the scientists hope it can be tipped with medicine or tiny amounts of radiation, then delivered to afflicted areas of the body.

The science may be small but the possibilities are big.