Jolt of java helps spermbots in final race to the finish

[Nipuna]

CAFFEINE gives you a spike of energy before you crash back down – even if you're a robot made from bull sperm.

Spermbots, as they are called, were first developed in 2013 by Veronika Magdanz of the Leibniz Institute for Solid State and Materials Research in Dresden, Germany, and her colleagues. She wanted to create a microscopic robot that could be used to deliver drugs around the body, and realised that sperm cells come with a built-in propulsion system: their flagellum.

The team trapped the heads of bovine sperm cells inside microscopic metallic tubes, then used a magnetic field to control their direction of travel, like a compass needle aligning with Earth's magnetic field. Since then, they've been looking for ways to boost the bots' performance.

Caffeine makes sperm go faster in humans, so the team tried adding some to the spermbots' swimming pool. The sperm absorbed the caffeine and increased their speed by 30 per cent on average, but only for around 30 seconds. A minute later, the spermbots were flagging at around 70 per cent of their original speed (Advanced Functional Materials, doi.org/f266dh). "The speed boost is only useful for a final 'race to the finish line' of the spermbots, when they need to be accelerated for a short time before they finish their task," says Magdanz.

Magdanz is also investigating how spermbots could be used in reproductive technologies, such as the controlled delivery of a single sperm cell.

This article appeared in print under the headline "Jolt of java helps spermbots in final race to the finish"