A team of engineers at The University of Texas at Austin say that they have built the smallest, fastest, and longest-running synthetic motor to date. This nanomotor, which could fit inside a human cell, is an important step toward developing miniature machines that could one day move through the body to administer insulin for diabetics as needed, or target and treat cancer cells without harming good cells.

The engineers based their efforts on building a reliable, ultra-high-speed nanomotor that can convert electrical energy into mechanical motion on a scale 500 times smaller than a grain of salt.

While the researchers designed, assembled, and tested their high-performing nanomotor in a nonbiological setting, the three-part nanomotor can rapidly mix and pump biochemicals and move through liquids, which is important for future applications

With all its dimensions under 1 micrometer in size, the nanomotor could fit inside a human cell and is capable of rotating for 15 continuous hours at a speed of 18,000 RPMs, the speed of a motor in a jet airplane engine. Comparable nanomotors run significantly more slowly, from 14 RPMs to 500 RPMs, and have only rotated for a few seconds up to a few minutes.

In the near future, the researchers believe their nanomotors could provide a new approach to controlled biochemical drug delivery to live cells. To test its ability to release drugs, the researchers coated the nanomotor’s surface with biochemicals and initiated spinning. They found that the faster the nanomotor rotated, the faster it released the drugs.