Saturday, September 15, 2007

Nanotech Roundup - 9/15/07

Silver is a potent antibiotic - this has been known for literally millenia.  And nanotechnology researchers have discovered that nanometer-sized silver particles are dramatically more effectively at weakening the cell membrane and disrupting enzymes that transport nutrients around the cell.  Unfortunately, pure silver nanoparticles react with their environment too much, and the unique nano-scale properties are destroyed when that happens.

Thankfully, though, antibiotics researchers are working to add a totally new class of nanotech-based antibiotic particle to the arsenal - single-walled carbon nanotubes (SWCNTs).

[B]y using highly purified, pristine SWCNTs with a narrow diameter distribution, they demonstrated that direct cell contact with SWCNTs can cause severe membrane damage and subsequent cell inactivation of E. coli bacteria.

Because silver particles and SWCNTs have antibiotic properties that are fundamental to the physics of how they interact with the cell, it’s much harder for bacteria to develop resistance.  And so, as the toxic properties of various kinds of nanotech are investigated to determine if they’re dangerous to human health and/or the environmental, we need to remember that sometimes toxicity isn’t a bad thing.  (See also this article on antibiotic SWCNTs)

Sometimes the potential for carbon-based nanotechnology makes it seem like buckyballs (C₇₀), carbon nanotubes, and graphene are all that’s really going on in nanotech.  Because nanotechnology is an enabling technology that makes almost every other technology you use better, it’s good sometimes to learn about other nanotechnologies as well.  In this case, researchers at the Georgia Institute of Technology have demonstrated the creation of metal oxide nanotubes that may easily mesh with existing electronics technologies and manufacturing processes.  These nanotubes may have properties similar to that of CNTs, but they may also have properties that are unique to the precise materials that make up the nanotubes (AlSiGeO, in this particular case).  Even more impressive, though, is the fact that the production of these nanotubes takes place in water, and varying the pH, water temperature, elements and concentrations in solution, etc. makes the production of these tubes very simple and easily controlled.  For now, at least, CNTs require very hot carbon plasmas (hundreds or thousands of degrees C), making metal oxide nanotubes very attractive where their properties will mesh up the the desired technological improvements.

Tying global heating and the climate to nanotechnology may seem like a stretch, but to give you an idea of the potential reach of nanotechnology, here’s an article about a company (Ecology Coatings) that’s developed a nanotech process that enables it to reduce the amount of energy it takes to coat metal, plastic, electronics, etc. by 90%.  The reason?  The coatings can be cured using ultraviolet light instead of high-energy electric or natural gas furnaces, and the significant savings in factory floor area when the furnaces can be removed and the area reused.  In addition, since the coatings are cured in less than a minute, the process time is dramatically improved over existing coating methods.  These coatings don’t use solvents so they are minimally polluting, excess coating can be filtered and reused, and the coatings are especially good for automotive and plumbing coatings, where the current processes require dangerous solvents and are very fragile.  Saving energy and boosting efficiency saves carbon emissions, and that’s good for addressing global heating.

Heading back into electronics for a moment, IBM has illustrated lab-bench operations of a single molecule switch and made the first measurements of the “magnetic anisotropy” of a single atom

Finally, researchers in Switzerland have created nano-scale particles of Portland cement that have the potential to harden in minutes.  The new nano-cement won’t work for most current applications because it’s too porous to create strong cement, but the researchers are confident that this is a problem that will be solved with more research.  Concrete that hardens in minutes and has stopped reacting in an hour or two has the potential to dramatically increase the rate of construction of pretty much every concrete structure in existence which, if you look around you, is pretty much everything constructed these days.  Instant road bed, anyone?