Periodic nanostructure formation on pet with femtosecond laser for control of cell elongation

Laser irradiation is carried out to form periodic nanostructures on the plastic surface. For example, polyethylene terephthalate (PET) was used in this study. Periodic nanostructures formation on PET is formed with excimer laser, because PET scarcely absorbs the light in the visible and infrared ray wavelength range. However, periodic nanostructures formation on PET is able to form with visible or infrared laser by combining PET with Si. For laser fluence, 60 mJ/cm2 and scanning speed, 20 mm/s, period and depth of the periodic nanostructures produced by the new method were about 650 nm and 80 nm, respectively. Cell test was conducted to examine cell spreading on treated and untreated PET. By cell test, cells were attached to periodic nanostructures of PET. Cells elongations were caused parallel to the grooves of the periodic nanostructures.