Printing, one molecule at a time …Thursday, June 28th, 2012 by Roberto Saracco
The jet-printer you may have on your desk prints photos and writings with tiny bubbles of ink, actually infinitesimally tiny: 2 billionth of liter a bubble (2 nano liters…).
Now scientists at the ETH Zurich Lab have decided they can use a similar technology to create nano tech objects: by printing them, one (or a few) molecule at a time. The molecules are kept in a solution through a solvent and a tiny drop of that solution can be printed on a surface with amazing precision. Once the bubble (that is detached from a capillary tip applying a voltage) hit the surface where it is being printed the solvent evaporates rapidly (almost instantaneously, remember we are talking about nano liters of solution!) and the molecules stick on the surface or on the molecules previously printed.
This turns out to be a very effective way to create nano objects. It is both cheap and fast. The technology of ink jet printers have been evolved for over 15 years and that has resulted in very accurate control of the ink using industrial manufacturing making the ink jet head very inexpensive.
Here the researchers had to tweak a bit with the technology to make it a bit more precise and to deliver even smaller droplets but it has been an incremental evolution.
Of course they also had to develop the right “ink” the right mixture of molecules that have to end up in the nano object and the solvent.
What is interesting is that as in an ink-jet printer you can move from black and white to color by using several inks (and printing heads) here one can also imagine to use several “inks” made of different molecules sprayed by different heads resulting in composite nano objects.
With this technology the researchers expect to be able to create smart materials that can be used for better photovoltaic systems, since nano tech can produce materials with a very high control of light refraction and reflection thus increasing the efficiency of solar panels, to create better and more accurate sensors, and also microscope that can detect a single molecule.
Going the nano way is enabling a whole new set of materials, designed on the bases of the properties we want them to have and this will open up a new world.