All aboard for a fantastic voyage

Scientists from Utah State University are working to create the first microscopic ‘submarines’ which could flow through the bloodstream to attack disease.

The team from Utah State University has used computer simulations to examine the prospect of using bacteria to propel small structures to deliver drugs to particular parts of the body.

According to Eldrid Sequeira from the university’s mechanical engineering department, bacteria such as salmonella and E. coli may be the perfect ‘motors’ for the subs.

As the bacteria swims through the bloodstream they could push or pull a minuscule disc, sealed within a liquid-filled cylinder. The system is said to be completely controllable as it is based on the chemotactic nature of bacterial motility.

With forces acting tangential to the disc, and bacteria oriented radially on the disc, the disc would rotate and the mechanical power generated by the microorganisms would act as the energy input source to a micro or nanosystem.

These discs could be drugs to treat tumours or break down the material lining blocked arteries.

‘Depending on the design we implement and with recent advances in nanoscale fabrication techniques, we could conceivably have micro-organisms power nanomachinery for extended periods of time,’ said Sequeira, speaking at the Foresight conference on nanotechnology in Maryland

Eventually, the Utah team believe they could build biomotors using only the flagella from the bacteria. This would, in theory, lead to the creation of biomotors billionths of a metre in size.

The team hope that their current computer simulations will be followed up with a prototype in a few months, probably using a wild strain of the salmonella bacterium.

Hot on the heels of the Utah team are Renaissance Technologies, who plan to start making medical robots smaller than a millimetre in diameter within a year. MicroTEC is also exploring the use of external magnetic fields as a power source for microscopic motors to travel around the body.