Will Future Computers Be All Wet?

Consider the molecule known as a 12crown-4 ether. This ring of 4 oxygen and 8 carbon atoms may seem simple, but its straightforward design conceals acrobatic talents worthy of the circus. When a lithium ion comes floating by, for example, the crown ether will pull it in and trap it in the ether's central cavity. But because the cavity has just the right charge and shape to recognize only a narrowly defined set of atoms, other ionseven closely related ones such as sodium or potassium-go right on by. And that doesn't