Researchers analyze minute quantities of blood, DNA, and other substances on a glass surface about the size of your hand. In this realm of microfluidics, suction or pumps are used to move the tiny droplets, but these methods tend to be inefficient. Is there a better way to transport liquids on a miniature scale? According to Dr. John Bush of the Massachusetts Institute of Technology, “nature has already solved these problems.”
Consider: The hummingbird does not waste energy by sucking a flower’s nectar into its mouth. Rather, it takes advantage of the cohesive forces that cause water on a flat surface to bead up and defy grav- ity. When a hummingbird’s tongue makes contact with nectar, the surface of the liquid forces the bird’s tongue to curl into the shape of a tiny straw, and the nectar is drawn upward. In essence, the humming- bird avoids unnecessary effort by letting the nectar force itself up the “straw” and toward the mouth. During feeding, hum- mingbirds can refill their tongue with nectar up to 20 times a second!
This “self-assembling siphon” has also been observed in some shorebirds, which drink water in a similar way. Commenting on this ability, Professor Mark Denny of Stanford University, in California, U.S.A., observes: “The combination of engineering, physics, and applied math is just wonderful . . . If you took any engineer or applied mathematician and told them to design a way for a bird to get water from its beak to its mouth, they wouldn’t have thought of this one.”
What do you think? Did the humming- bird’s tiny tongue—with its ability to collect nectar rapidly and efficiently—come about by chance? Or was it designed?