Meet The Fastest Creatures On Earth, Microscopic Protozoans That Could Inspire A New Class Of Nanobots

Scientists plan to study the tiny critters in order to mimic their ultra-fast movement and adapt it for nanotechnology.

Spirostomum ambiguum, the fastest creature on Earth.
ExaVolt / Wikimedia Commons/Cropped and Resized (CC BY-SA 4.0)

Scientists plan to study the tiny critters in order to mimic their ultra-fast movement and adapt it for nanotechnology.

The fastest creature on Earth is not the cheetah or the falcon, but a microscopic single-cell organism called Spirostomum ambiguum — a worm-like protozoan that measures just four millimeters in length (0.15 inches) and can be found in just about any body of water.

This tiny creature is too small to see with the naked eye, but a look under the microscope reveals that it’s capable of great things, which dwarf the impressive performance of the other two contenders.

While the cheetah can sprint at speeds of more than 60 mph (96.5 km/h) and the falcon is able to dive at a whopping 250 mph (400 km/h), Spirostomum ambiguum can move even faster, shows the Georgia Institute of Technology.

“The smaller they are, the faster they go — up to 200 meters per second squared [650 feet per second squared]. That’s really off the charts,” says Saad Bhamla, an assistant professor at Georgia Tech, who recently received a four-year grant from the National Science Foundation to study Spirostomum ambiguum and find out how the little critter is able to move so fast.

According to the university, its secret lies in a trademark move which allows the protozoan to contract its body at unbelievably high speed and shrink into a football shape 60 percent shorter than its normal size. All this in just “a few milliseconds.”

This amazing skill is still largely an enigma to us, since no one has been able to figure out how Spirostomum ambiguum can pull this off and not crush all its internal structures in the process.

Bhamla hopes to be the one that cracks the mystery.

“It has internal organelles, DNA and delicate cytoskeletal components inside,” he said. “We want to understand how they are not damaged by the rapid compression, because the internal pressures must increase rapidly.”

This precious knowledge could later be used to advance nanotechnology and develop a new generation of tiny robots that can employ the same kind of movement to substitute the usual grasping and propulsion technologies available for larger models.

“As engineers, we like to look at how nature has handled important challenges,” said Bhamla.

His hope is that he will be able to understand how Spirostomum ambiguum moves well enough to break down the process and adapt it for nanobots, notes Live Science.

“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,” he pointed out.

The trick is finding out which molecules are at work here, since Spirostomum ambiguum is clearly not relying on the same kind on proteins that make our muscles function. If that were the case, these protozoa “couldn’t generate enough force to actually move that fast,” explains Bhamla.