Clues in the cucumber’s climb
Harvard researchers, captivated by a strange coiling behavior in the grasping tendrils of the cucumber plant, have characterized a new type of spring that is soft when pulled gently and stiff when pulled strongly. Instead of unwinding to a flat ribbon under stress, as an untwisted coil normally would, the cucumber’s tendrils actually coil further. Understanding this counterintuitive behavior required a combination of physical and mathematical modeling and cell biology — not to mention a large quantity of silicone. The result, published in the Aug. 31 issue of Science, describes the mechanism by which coiling occurs in the cucumber plant and suggests a new type of twistless spring. Led by Professor L. Mahadevan, the researchers were motivated by simple curiosity about the natural world. “Nature has solved all kinds of energetic and mechanical problems, doing it very slowly and really getting it right,” says lead author Sharon Gerbode, a former postdoctoral fellow at...