A team of University of Texas at Austin engineers and researchers have come up with a new method for manipulating small particles in the 1~100nm realm.
Using a focused laser beam, the team heated an area under a sheet of gold nanomaterial. Provided moisture creates an expanded sphere of vapor that due to the differences between gas pressure, surface tension, surface adhesion and convection, can attract and capture nanoparticles.
The beam can be steered to anywhere on the plane, while the entrained nanoparticles remain in the bubble and are brought along with the laser beam. The particles can then be deposited at will by simply extinguishing the coherent light beam. This allows the rapid assembly of particles into any shape desired.
The beam power controls the bubble size, which determines the amount of material to be transported. The method should allow leveraging by many existing software tools used in machine-tool control and 3D printing. This is because the bubble-pen method is very similar to the well-understood general Euclidean x, y, z machine control already used by thousands of tools.
This technique is expected to be useful for anyone trying to quickly assemble nanostructures to test designs in meta-materials, bulk semiconductor development like photo-voltaic materials, battery development and pharmaceuticals. If the temperature can be held low enough, the team believes biological manipulations of bacteria and viruses will also be possible. There is the expectation that nanomachines, optical computers and biomedical sensors could all benefit from this interesting development.
I'm looking forward to the outstanding possibilities this provides in the aforementioned meta-materials. There's a great deal of interest in discovering more efficient ways to transform solar radiation into electricity that is not based on the now-conventional P-N junction method.
One possible method is based on using actual antennas to “receive” the electromagnetic radiation, similar to the Yagi antennas used to receive television signals. The difficulty comes from the radically smaller dimensions needed to fabricate antennas to receive the considerably smaller light wavelengths compared to radio wavelengths. Having a system that could build nano-scale antennas quickly to test many different theories and to allow development and refinements of simulators would be spectacular.
The researchers describe their device and technique in a paper published in Nano Letters.