microelectronics is when you are making extremely small devices to accomplish tasks, like making a robot the size of a mosquito or something. Nanoelectronics is making devices at cellular sizes. Nanoelectronics may be the future of medicine. They have the ability to replicate themselves, so you send a few into a person with a needle injection, to attack and destroy a tumor, or repair a ruptured spleen or something. Nanoelectronics is both amazing and a little scary. But very cool.