The creature isn't a cheetah or a falcon; instead, it's a single-celled organism called Spirostomum ambiguum, commonly found in bodies of water. Cheetahs can sprintat speeds of more than 60 mph (96.5 km/h), and falcons may dive at well over 250 mph (400 km/h). But S. ambiguum can move even faster, shortening its body by 60 percent into a football shape within "a few milliseconds," according to a press release.
这种生物既不是猎豹也不是猎鹰，而是一种名叫Spirostomum ambiguum的单细胞微生物，通常能在水体中找到它们。猎豹的冲刺时速可以超过96.5公里/小时，而猎鹰的俯冲时速可以超过400公里/小时。但是根据一篇新闻稿，S. ambiguum的移动速度甚至更快，能在“短短几毫秒”的时间内能将身体缩短60%变成一个球形。
But researchers have no idea how the single-celled organism can move this fast without the muscle cells of larger creatures. And scientists have no clue how, regardless of how the contraction works, the little critter moves like this without wrecking all of its internal structures.
Saad Bhamla, a researcher at Georgia Tech, received a grant from the National Science Foundation to study and model S. ambiguum's contraction motion at the subcellular level. He hopes to come to understand the motion well enough, he said, to break it down into ideas that could be used for robots.
"As engineers, we like to look at how nature has handled important challenges," Bhamla said in the release. "We are always thinking about how to make these tiny things that we see zipping around in nature. If we can understand how they work, maybe the information can cross over to fill the gap for small robots that can move fast with little energy use."
When you curl into a ball like the S. ambiguum, or sprint like a cheetah, or dive like a falcon (the latter is not recommended, except possibly into very deep swimming pools), you activate actin and myosin proteins in your muscle cells that contract to generate motion, the statement said.
But tiny creatures like S. ambiguum don't rely on proteins of that sort, Bhamla said. (S. ambiguum exists on a sort of fuzzy boundary between animals and non-animals. Older texts often considered single-celled "protozoans" like this, which have animal-like characteristics, to be part of the animal kingdom. But more recently biologists have tended to separate them into their own kingdom of life, known as Protista.)
"If they had only the actin and myosin proteins that make up our muscles, they couldn't generate enough force to actually move that fast,” Bhamla added. "The smaller they are, the faster they [accelerate] — up to 200 meters per second squared [650 feet per second squared]. That's really off the charts."
Instead, the creatures use alternative, complex molecules to achieve both motion and tasks like moving their internal structures around.
Bhamla hopes, he said in the release, that the molecules at work in this motion might lead to meaningful technological jumps, which in turn could lead to improvements on existing nanorobot technology.