There are many diseases out there that are terminal. Many only leave a person with up to a year to survive and modern medicines seem to only delay the inevitable. Thus, doctors and scientists began to develop nanobots with the hope that they could be the future of medicine. You see, the major problem with contemporary treatment, like chemotherapy, is that it is inefficient. It is basically a toxin that kills every single cell‒cancerous or healthy‒that it comes across. Imagine how effective chemotherapy could be if it just targeted cancerous cells. This could theoretically be possible with nanobots, as a small amount of a chemotherapeutic agent could be put into millions of nanobots that were programmed to only kill cancer cells. However, there is still a lot of research that needs to go into nanobots in order for them to be effective disease killers. An individual bot must be able to drive itself, effectively locate dangerous bacteria/viruses/cells, destroy itself after its mission is complete, and avoid knocking into other objects including the millions of other nanobots. And along with that, they need to be inexpensive, which probably is not going to be the case for awhile.
So it is clear that it might be a few years or decades before nanomedicine becomes practical, but there is another major use for nanobots. You might remember the great BP oil spill that devastated the Gulf, leading to disastrous environmental impacts and major health complications for animals within the 68,000 square mile affected area. Modern methods to control and clean up oil spills are quite simple: plug the hole or valve releasing the oil, stop the pressurized systems that transport the oil, and then use skimmers to pick up all oil that escaped.
This has proven ineffective in the past, as simply plugging the leaking areas does not actually solve the root cause of the issue and it is really hard to ensure that all possible breaches are covered up, especially since most leaks occur deep underwater. Also, the skimmers used to clean up the leaking oil are usually only effective in calm water and can get clogged easily due to floating debris. Considering the fact that it took years to completely stop the BP oil rig leakage and that thousands of wildlife are still affected, there needs to be a change in the way we handle oil spills. And as you have already predicted, that change could be through nanotechnology. As opposed to nanobots being filled with something to eject later on (like in nanomedicine), nanoparticles would be used to magnetically separate oil from water particles scattered throughout the ocean. Essentially, scientists could combine water-repellent materials with a metal, like iron, to attract oil away from water. Similar to how it would detect dangerous cells within the human body, robots could be programmed to find oil within a sea of water and other materials. With millions upon millions of these tiny superbots, a leak could at least be contained. This could lead to lots of wildlife being saved as they would not be exposed to oil. You might think that lots of money would still be lost since oil leaking from the rig is no longer usable, but you are mistaken. The extremely small amount of oil gathered by each nanoparticle could be reused. The oil company would not lose as much money as they might expect because a large amount of the oil lost could be regained through the use of these compound nanoparticles.
The truth is that nanotechnology is still a long way from being practical. There is still a lot of research to be done on the uses of nanorobots and their potential effectiveness when it comes to administering medicine. Nanomedicine is not the only use for nanotechnology, however, it is arguably the most important field that could develop due to advancements within the field. Even when official prototypes are created, there is still the major issue of cost. If nanobots are too expensive to use, it may limit nanotechnology’s ability to become mainstream. This is also true when talking about nanotechnology’s role in cleaning up oil spills. Currently, it appears that the cost to create effective water-repellent metal nanoparticles is too great. While oil spills certainly do not occur often, it is still important that the creation of these nanoparticles cheapens so that there is no hesitation when it comes to using them when they are needed the most. So maybe the 1950s version of the future really is coming true, and robots really will just do all the work for us. Sounds pretty nice to me.