I am not afraid to consider the final question as to whether, ultimately---in the great future---we can arrange atoms the way we want; the very atoms, all the way down! What would happen if we could arrange the atoms one by one the way we want them (within reason, of course; you can't put them so that they are chemically unstable, for example).
We're talking nanotechnology here, the stuff that deals with tiny machines only a nanometer thick (one billionth of a meter). If you think this is impossible, just take a look at technology today. It will inevitably get smaller; example: take a look at your mobile phone. Then take a look at one made 15 years ago, now can you see the difference?
Nanotechnology is a science combining both engineering and chemistry. Atoms and molecules stick together because they have complementary shapes that lock together, or charges that attract. Like protein with it's equivalent enzyme. As with magnets, a positively charged atom will stick to a negatively charged atom. As you 'sew' or 'knit' the atoms together it will begin to form the shape of an object. The goal of nanotechnology is to manipulate individual atoms and place them in a pattern to form a desired structure.
Scientists believe they can now manipulate individual atoms. To do this they must find a method to grab an atom and move it into a desired position. This is a little like trying to piece together the tiniest lego you can find, while wearing boxing gloves, yes, boxing gloves. In 1990 an IBM research team knitting together individual atoms to spell out 'IBM'. They positioned 35 xenon atoms on the surface of a nickel crystal, using an atomic force microscopy instrument.
The next step will be to develop nanoscopic machines, called assemblers , that can be programmed to manipulate atoms and molecules at will. It would take thousands of years for a single assembler to produce any kind of material one atom at a time. Trillions of assemblers will be needed to develop products in a viable time frame. In order to create enough assemblers to build consumer goods, some nanomachines, called replicators, will need to be programmed to build more assemblers.
The first products made from nanomachines will be stronger fibers. Eventually, we will be able to replicate anything, including diamonds, water and food. Nanotechnology will be needed to create a new generation of computer components. Molecular computers could contain storage devices capable of storing trillions of bytes of information in a structure the size of a sugar cube.
Nanotechnology could even begin to impact the medical world. Patients will drink fluids containing nanorobots programmed to attack and reconstruct the molecules of cancer cells, or viruses to make them completely harmless. Nanomachines could even be uses in the most delicate parts of surgery, nano-surgeons that will leave no scaring, and will be even more precise than the sharpest scalpel.
Nanotechnology could even benefit the environment. For instance, airborne nanorobots could repair the thinning ozone layer. Containments from water sources, and oil spills could be cleaned instantly. Our dependence on non-renewable resources would diminish with nanotechnology. Many resources could be constructed by nanomachines. Cutting down trees, mining coal or drilling for oil may no longer be necessary. Resources could simply be constructed by nanomachines.
The promises of nanotechnology sound great, don't they? Many researches believe we will reach these capabilities within the next century.