Incredible Shrinking Bee, The: Insects As Models For Microelectromechanical DevicesBecause vertebrate circulations do not work when shrunk to insect sizes, insects may help us design our smallest machines. Within small bodies, bees separate diffusing substances in an open cavity assisted by locomotion and the beat of the heart. The open arthropod circulation, however, is most efficient when shrunk until its large three dimensional volume of blood turns into a two dimensional film of fluid covering only the internal surfaces. This