TECHNOLOGY: Laser Nanomachining

While the nanomaterials and devices developed in nanoscience labs hold a great deal of promise in their future applications, scalability remains an issue. The jump in quantity of nanomaterials required in basic research to that required for mass scale manufacturing is a formidable one. In fact, one of the largest obstacles on the path to bring progress in nanoscience to mainstream markets is that of manufacturing. A recent paper published in PNAS offers a potential solution in a method of machining with ultra-fast laser pulses that can carve into materials with precision on the order of nanometers.

In their paper, this group, led by Dr. Alan Hunt from University of Michigan, found that by using laser pulses on the order of femtoseconds (1 millionth of a nanosecond), they could carve holes and canals (see figure) in metals nanometers wide while doing very little damage to areas outside the target zones. This method of carving involves freeing up electrons with each laser pulse and accelerating them to tunnel through the material, exciting electrons that they encounter on the way in what is described as an "avalanche effect". The extremely short pulse durations used in the experiment constrict this effect to within target zones and result in cuts which appear smooth down to 4nm resolution.

This laser nanomachining has a wealth of applications in the nanotech industry. Its speed and ease of manipulation far outmatch the capabilities of current methods of nanolithography. Laser nanomachining will most likely find a niche in electronics industries for its promise as a nanoscale mill. Its foreseeable applications are destructive (as opposed to constructive layering of nanomaterials), and carving will probably be the largest role for this technology. Laser nanomachining provides speed and manipulation similar to that of traditional milling and will likely serve similar purposes - albeit on a nanoscale.

(FIGURE from article)