Water Striders

As a child I sometimes watched these spider-like creatures skate across the top of a pond on the farm. I thought little of it besides just assuming they were too light to sink. I knew nothing about the surface tension of water that creates an invisible “skin” as the water molecules at the top “cling” to each other. This same tension causes water droplets to form a bead on surfaces like glass. They don’t flatten out like most liquids.

Robotics engineers have sought to copy that insect’s ability. Perhaps they could create a small enough surveillance device or drone capable of the water strider’s feats. In 2005 robotics engineers reported the production of the first robot to mimic the water strider’s ability to skate on water. This field of study is called biomimetics, and the production of these robots is biorobotics. However there is still a long way to go. The strider can jump up to 6 times as high as its own length, then land safely without crashing or sinking. Man-made robots still either crash on land or sink on water. To quote David Catchpoole in Creation magazine (Vol. 39, No. 3, 2017) the hurdles to overcome include the following.

“Ten years on and researchers, intent on copying the leaping prowess of the water strider, have made impressive progress. 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 the 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 maximizes the overall force for their jumps.”

The water strider didn’t decide to develop this nor did it come by accident or chance mutations. It was wonderfully designed by a Very Intelligent Designer.

There are so many wonderful things in nature that honor the Creator.

Henry Wiebe