Interesting tech developments in nanotech, nanostructured materials, etc.
Thursday, February 17, 2005
WorldChanging: Nanotechnology and the Developing World: "the Global Dialogue on Nanotechnology and the Poor [is] a project intended to trigger a conversation about the ways in which nanotechnology can be applied to the problems of development and poverty. Anyone may participate .." SciDevNet covers the conference and has an introduction to the material. The 29-page report covers risks as well as benefits, with a useful appendix showing the UN Millenium Goals for reference.
This has been a major interest of mine since 2000. The bottom line for me came down to two things: nano-engineered materials for energy and water. Nanotech's first fruits are a new universe of materials with electrical and chemical properties that will offer new options to engineers of all goods, including those meeting basic needs. It's like plastics a century ago; we're at the start of a decades-long absorbtion of new possibilities, both good and bad. This time the changes will come faster, sped up by computer-aided design and manufacturing. (Nano-assembly, whenever it arrives, will only further add to the changes.)
For developing countries, the key benefits are in the basics for manufacturing and urban life.
- purified or desalinated water
- distributed electric generation and new options for fuel, ideally from renewable sources with hydrogen and/or battery storage of power
- more efficient use of energy and materials overall
I think this will be on balance good for the environment, in its greater material efficiency. However, nano-engineered materials will also be applied to increase the efficiency of raw material extraction, such as taking fossil fuels from the earth faster and cheaper. It will also give rise to more extravagant ways to use energy in the developed world, perhaps super-sonic transport, large-scale military applications, or ever-larger interiors for housing and commerce. I am optimistic that enough funding and volunteer attention will be given to pollution-reducing and poverty-alleviating applications to tip the balance. (I think that the top-down and exploitative applications have been refined so much already, that it's probably easier for researchers and innovators to have a big impact in the less-explored sustainable applications.) 1:37:18 AM
Nanotubes crank out hydrogen
: "Several research efforts are using materials engineered at the molecular scale to tap the sun as an energy source to extract hydrogen from water. Researchers from Pennsylvania State University have constructed a material made from titanium dioxide nanotubes that is 97 percent efficient at harvesting the ultraviolet portion of the sun's light and 6.8 percent efficient at extracting hydrogen from water.
The material is easy to make, inexpensive, and photochemically stable, according to the researchers. The 97 percent efficiency is the highest reported, according to the researchers. There is one catch -- only five percent of the sun's energy is ultraviolet light. The researchers are working to find a way to shift the response of the nanotube arrays into the visible spectrum. The key to making titanium dioxide nanotubes that efficiently harvest the energy from light is controlling the thickness of the nanotube walls, according to the researchers. Nanotubes 224 nanometers long with 34-nanometer-thick walls are three times more efficient than those that are 120 nanometers long with 9-nanometer-thick walls.
The researchers made the titanium dioxide nanotube material by mixing titanium with acid and electrifying the mixture, which caused the tiny tubes to grow, then heating them to cause the material to crystallize." [via WorldChanging
] 1:01:08 AM