Examples of fullerenes: http://www.chem.sunysb.edu/msl/fullerene.html
What fullerenes are: http://www.chemistry.wustl.edu/~edudev/Fullerene/fullerene.html
Also a one atom thick material with interesting properties: http://www.physorg.com/news5341.html
On the piezoelectric qualities of bones: http://silver.neep.wisc.edu/~lakes/BoneElectr.html
Check out the pictures of nano-cars and nano-gears here: http://en.wikipedia.org/wiki/Nanotechnology
Material
The material from which my self replicating structure would be made of would be a semi-metallic and semi-organic material with the strength and tensile properties of metals, but the healing, and growing capabilities of an organic material. To be able to accomplish this the material would have be responsive to stimuli of different kind, including but not limited to, light, temperature, sound, pressure, and electricity.
Bones in animals are actually responsive to pressure because they are a piezoelectric material. When a piezoelectric material is under pressure, a current runs through it. In human bones, this current varies with pressure, and stimulates growth. It is for this reason that astronauts suffer from bone deterioration in space, because the pressure on their legs is greatly diminished, and the bone withers away. Bones that do not experience pressure on earth tend not to deteriorate in space. This is why martial artists do knuckle pushups, and why broken bones repair themselves.
My material would respond in a similar way. It would respond to stimuli of different kinds, and it could grow, replicate, and heal itself. It would be modeled much like the fullerenes discussed above, strong, highly symmetrical molecules that are easy to assemble, and naturally come together, mirroring the shapes that define sacred geometry. Much like a broken bone that mends itself, this semi-organic/metallic element would seek equilibrium and order, and would tend to recreate and perfect itself. The elements that make up the material could be constructed using nanotechnology and nano-machines, infused with DNA type program coding that determined their purpose. Since the information comes from nature, the material would naturally want to reproduce, and be in a state of homeostasis and equilibrium. Ideally any self replicating structure would be habitable, and could be interactive, taking on the look of the projects created by "interactive architecture"
Response
I am strongly against censorship of any kind, so the claim that Steven Kurtz may have been imprisoned due to the fact that his work is considered a form of social criticism is an appalling thought. That being said, I am also a libertarian on many levels, and I feel that people should be free to do anything, as long as it does no harm to any other person or to the environment, or community. The issue of genetic manipulation and engineering is touchy because one can never avoid discussing the sacredness of life. When people speak of abortion, or stem cell research, the concept always comes up, and there is never a clear answer as to when a group of cells can be considered life, or a human, or a living thing. The whole idea becomes a messy concoction of religion, politics, philosophy, economics, and at times, metaphysics. While I do support stem cell research, my views on destroying embryos to get them are muddy. There has been progress in obtaining stem cells from other means, and if that becomes the case, than I wholeheartedly support it.
Knowledge and discovery is an important part of who we are as humans. Seeking for truth I think is one of the meanings of life. We travel to space, to the depths of the ocean, and we're always learning about things. Some things we study are as small as DNA or even subatomic particles, and we work our way up to galaxies and the universe. This should never stop; we should be constantly exploring and learning about ourselves. If we study to learn and advance ourselves and promote our evolution as a species, then the purpose is good.
If we study genetic engineering to control how our children will look, that's not so good. Curing diseases is a noble cause, but let's not underestimate nature's ability to develop newer and even more powerful diseases. If the human life span increases dramatically, does Earth have enough resources to maintain a growing population. The issue is touchy, and we have to ask ourselves if we truly are transcending ourselves and nature.