By Peter Weiss
Some 300 years ago, microscope inventor Antony van Leeuwenhoek stunned the world when he became the first to observe “animalcules” that were “very prettily a-moving” in human saliva and other excretions. Now, a human-rigged device has joined the menagerie. To a red blood cell, scientists in France have attached a wavy tail that responds to magnetic fields. When changes in those fields wiggle the tail, the red blood cell swims.
Experiments with that device have given researchers insights into the physics that tiny swimming creatures have to master. Along with other micromachines making their way from the drawing board to the real world, such devices may someday prove useful in disease research or industry.