October 1, 2007
1 min read
Add Us On GoogleAdd SciAmPaddle-Free Swimming
By Charles Q. Choi
On supporting science journalism
If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.
For microscopic swimmers, paddling is hard because at such tiny lengths, water seems as thick as honey. To get around this viscosity, scientists from the University of Sheffield in England and their colleagues have developed plastic swimmers without moving parts. They coated 1.6-micron-wide balls on one side with a thin layer of platinum and dropped them in a solution of hydrogen peroxide and water. The metal catalyzes the breakdown of hydrogen peroxide into oxygen and water, propelling the balls at speeds up to five microns per second, half as fast as similarly sized bacteria move. After a few seconds, the balls start to jostle with surrounding atoms and molecules and then meander, but the designers suggest that magnetic fields could guide the swimmers. They could also adapt them to work in fluids such as blood, to help deliver drugs within the body. Wade into the findings in the July 27 Physical Review Letters.
It’s Time to Stand Up for Science
If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.
I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.
If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.
In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.
There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.
