A group of physicists recently built the smallest engine ever created from just a single atom. Like any other engine it converts heat energy into movement — but it does so on a smaller scale than ever seen before. The atom is trapped in a cone of electromagnetic energy and lasers are used to heat it up and cool it down, which causes the atom to move back and forth in the cone like an engine piston.
The scientists from the University of Mainz in Germany who are behind the invention don’t have a particular use in mind for the engine. But it’s a good illustration of how we are increasingly able to replicate the everyday machines we rely on at a tiny scale. This is opening the way for some exciting possibilities in the future, particularly in the use of nanorobots in medicine, that could be sent into the body to release targeted drugs or even fight diseases such as cancer.
Nanotechnology deals with ultra-small objects equivalent to one billionth of a meter in size, which sounds an impossibly tiny scale at which to build machines. But size is relative to how close you are to an object. We can’t see things at the nanoscale with the naked eye, just as we can’t see the outer planets of the solar system. Yet if we zoom in — with a telescope for the planets or a powerful electron microscope for nano-objects — then we change the frame of reference and things look very different.
However, even after getting a closer look, we still can’t build machines at the nanoscale using conventional engineering tools. While regular machines, such as the internal combustion engines in most cars, operate according to the rules of physics laid out by Isaac Newton, things at the nanoscale follow the more complex laws of quantum mechanics. So we need different tools that take into account the quantum world in order to manipulate atoms and molecules in a way that uses them as building blocks for nanomachines. Here are four more tiny machines that could have a big impact.