High-tech Amazon spider amazes scientists

A spider 1 millimeter long can stretch its web back and fling it forward at an acceleration rate 100 times that of a cheetah. The snapping action, which allows it to surprise unsuspecting flies and mosquitoes as they cruise by, relies on a silk spring mechanism that surpasses anything humans have designed, scientists say.

Researchers at the Georgia Institute of Technology traveled deep into the Amazon rainforest of Peru to study how the slingshot spiders work. When the arachnids release the tension on their webs, they snap them forward at a speed of 13 feet per second and withstand 130 G’s of force—10 times what a fighter pilot can tolerate before blacking out. The slingshot action likely “gives the spider the advantage of speed and surprise” needed to catch and maybe even stun its much bigger flying prey, researcher Symone Alexander said.

In the study, published in Current Biology in August, the researchers used ultrafast cameras to record the spider’s movement. They discovered the spider weaves a new, cone-shaped web every night with a tension line at its center. While the spider walks along the tension line, it produces a small bundle of silk. It stretches the silk with its front legs and tightens the tension line while clutching the web with its hind legs, creating a sophisticated 3D spring. When an insect gets within range, the spider moves backward with the silk wad to increase the tension, like pulling back a slingshot. When the prey gets close enough, the spider releases the bundle that controls how much the web moves.

The researchers believe the spider can hold a ready-to-launch pose for hours because, instead of using its leg muscles to jump, it uses a latch mechanism to release its spring and launch itself into the air.

After a successful catch, the spider quickly wraps its prey in silk. If it misses, it pulls the tension line and resets the web launcher.

“If you compare this natural silk spring to carbon nanotubes or other human-made materials in terms of power density or energy density, it is orders of magnitude more powerful,” researcher Saad Bhamla said.

He and his colleagues hope the discovery will eventually help scientists design sources of power for tiny robots and other devices. “Nature does a lot of things better than humans can do, and nature has been doing them for much longer,” Alexander said. For Christians, that understanding points to the wisdom of the God who designed nature.