High-quality parallel patterning of carbon nanotube thin films by a pulsed laser beam

Single-walled carbon nanotube thin films solution-deposited on the glass substrate were directly patterned by a spatially-modulated pulsed laser beam (wavelength = 355 nm, pulse width = 5 ns) incident from the backside of the substrate. This method utilizes a ultrashort pulse-induced strong thermo-elastic force exerting on the film which plays a role to detach it from the substrate. The threshold energy density required for patterning was as low as 90 mJ/cm ², making it possible to pattern over a few square centimeters by a single pulse with maximum energy of 180 mJ. The irradiated regions of the film were clearly photoetched without leaving any residual nanotubes. High-fidelity patterns could be fabricated with a feature size of 35 μm.