Hello all. I described the nanofactory concept to someone and they responded with the following statements. I would like you all to examine this and pick apart their claims.
Here is what they said to me:
"Thanks for your article. I haven't read too much on the subject, but one of the obstacles I see to making this a practical reality is the energy it would take to make things. I would imagine that is why solar is one of the prefered choices. That said, you would need an enormous amount of stored solar energy to make even a small object. Here are some of the reasons I see for this.
When we manufacture something, let's say a watch to keep things small, you first need the correct amounts of raw materials...various metals, glass, perhaps plastics or silicon if it has a computer chip in it. In a tradtional factory, you simply fashion the raw materials into the parts you need (often made in several other factories dealing with different raw materials) and then assemble them according to the design spec for that watch.
With nano tech, you will still need the same raw materials in molecular rather than atomic form. The reason is that the raw materials just would likely not be as abundant in nature in a pure state as you would need. Every metal has to be refined to make it as pure as possible before it can be used. This means you now need the energy to decompose molecules into their respective atoms and separate them into their own storage containers. The molecular decomposition is probably were chemical eneregy comes in. The problem now is that you introduce danger during what I'll call the "un-manufacturing" process due to the unstable nature of many elements and the use of the chemicals needed to achieve this.
Once you have your elements separated, you now need to supply the energy to run the machine that will inject the correct amounts of each to fashion the molecules and compounds containing mixtures of molecules (basically getting back to your original raw materials), and assemble them correctly.
I think that the computer processing required for this would be far greater than we currently have available as well. I could just imagine Google's entire server farm of several thousand networked computers being needed to make that one watch over a period of several hours or even several days. It can take a full day to render a 2-hour video from the raw source on my Mac Pro running a 2.93 GHz quad-core processor and 8 GB of RAM.
Now let's take a step backward and consider what it would take if you could use "anything" to make something with nano tech. We'll put in my old running shoes and get out a steaming cup of hot chocolate. You have just dramatically increased the energy, size of machine, and time/processing as well as danger involved. Now you are no longer talking about breaking apart molecules into atoms and reforming them, but now you have to change non-edible plastics and rubbers into edible water and chocolate. You are going subatomic now and removing or adding electrons. Forget about unstable elements...now we have a potential nuclear explosion on our hands. It would take tremendous energy to break away an electron from the atom. Then you have the stray electron floating around causing a release of nuclear energy. Keep in mind that for every electron you strip away from an atom, you need to take away a proton in most cases to maintain a stable atom. If that weren't impossible enough, try taking loose electrons and protons (which shouldn't exist on their own) and cramming them into an atom to form a heavier element. You are looking at a recipe for atom smashing, aka a nuclear reactor, no matter how you look at it.
I don't believe that nano tech in the form of 3D printers will be able to give Captain Pickard his cup of hot chocolate on the USS Enterprise, but it may be most practical in the form of nano machines in the medical field, for example, to eliminate a virus from the body or repair a damaged blood vessel, dissolve a blood clot, repair damaged cartilage in a knee, etc. Of course there are many dangers to this as well. Many disseases could be cured, but new ones could be created either unintentionally or intentionally for terrorist means. For many medical conditions, nano tech will never be able to do better than what the human body can already do through adult stem cell treatments. Just imagine getting an injection of nano machines meant to dissolve a blood clot, but instead you react differently to it and end up with anemia or worse like internally bleeding to death."