This article is from
Creation 39(3):12–13, July 2017

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Nature’s creatures do ‘impossible’ things

Water striders are strides ahead of robotics engineers, and fleas have the jump on them, too

by David Catchpoole

For some years now, the dramatically expanding field of biomimetics (engineers copying biological design) has seen an increasing number of God’s creatures inspiring new designs and system improvements in robots and drones.¹ As Assistant Professor Metin Sitti, the head of Carnegie Mellon University’s Nano-Robotics Laboratory, said in 2006, “Because nature has so many creatures that seem to accomplish the impossible, there is no better source of inspiration.”²

Of course, it’s rare to find public reports of biomimetic breakthroughs crediting God rather than the more politically correct ‘nature’. Generally the original designs are incorrectly attributed to ‘evolution’, not to the One “who created the heavens and the earth and the seas and all that is in them” (Exodus 20:11). But it defies reason to suggest that these creatures were not intentionally and intelligently designed, especially when one considers that the best whole teams of the brightest human engineers can come up with still falls short of the prowess of the original in so many ways. (Even in respect to the one feature the engineers are usually trying to copy!)

A good example is the water strider. In 2005, robotics engineers reported having created the first robot to mimic that insect’s ability to skate across the surface of a pond, with its weight supported by the surface tension of water.³ (Surface tension is the same phenomenon that makes water droplets bead up.)

The water-skating robot was quite an achievement, but the water strider insect was still strides ahead of engineers. They could not yet explain, let alone emulate, the water strider’s ability to leap from the water surface, jumping just as high as it would from solid ground. E.g. South Korean water striders 1.3 cm (0.5 inch) long can jump more than 8 cm (3 inches) high above the surface of the water—six times their body length.

Ten years on, and researchers intent on copying the leaping prowess of the water strider have made impressive progress.^4,5 Using high-speed cameras and other equipment, the researchers observed that the water strider’s legs accelerate gradually, so that the surface of the water does not retreat too quickly (which would mean losing contact). They found that the maximum force exerted by the water strider’s legs approaches, but never exceeds, the opposing vertical component of the water’s surface tension (and therefore the legs don’t sink). They also observed that water striders sweep their legs inward to lengthen the time period they can push against the surface of the water. Furthermore, the curved tips of their legs are just the right shape to adapt to the dimples that form on the water’s surface when the legs push downwards, thus enhancing to the fullest possible extent the surface tension on the legs. All of this works to maximize the overall force for their jumps.

Armed with this new knowledge, the engineers have built their own lightweight robot which can jump 14 cm (5.5 inches) above the surface of the water—about the same as the length of its ‘body’. Like the insect water strider, the robot can jump on land as well as water, but at this stage it can jump once only, and lands randomly. “[U]nlike a living water strider, this first generation of robo-striders can’t get back up after a splash—or crash—landing.”⁶

Ultimately the researchers aim to build a robot capable not only of controlled landings and repeat jumps, but also of carrying the necessary electronic equipment (e.g. batteries and sensors). They foresee it would be useful for surveillance, search-and-rescue missions and environmental monitoring.

Incidentally, the jumping mechanism used in the robots was not copied from the water strider, but from the flea. So (at least) two creatures provided the inspiration for the robot. As Kyu-Jin Cho, one of the researchers and Director of the Biorobotics Laboratory at Seoul National University, said, “Natural organisms give a lot of inspiration to engineers.”⁷

Those ‘natural organisms’ didn’t originally come about naturally, but supernaturally, just as we did—but with one important difference. Unlike water striders and fleas, we were created in the image of the Creator Himself (Genesis 1:26–27), so no wonder man alone among all the creatures has the capacity to study and even copy what God has made. And even if one of our creations might eventually match some aspect of His handiwork, we should never forget who thought of it first.

From The American Association for the Advancement of Science, Two leaps forward for robot locomotion. Reprinted with permission