Wettability measurements of agarose thin films patterned by 193 nm ArF excimer laser

Abstract

The control and knowledge over liquid–solid interactions is vital for the design optimization of materials, processes in a variety of uses. Thus, investigating wettability plays a great role in such interactions. In this paper, characterisation and the effect of 193 nm excimer laser patterning on the agarose thin films are studied. Different techniques; atomic force microscopy (AFM), scanning electron microscopy and white light interferometer are used to characterise the agarose thin films. UV–Vis spectrophotometer was used to measure the absorption and transmission of thin films. An absorption coefficient and grating period of 1.7 × 10³ cm⁻¹, and 11.5 μm respectively are reported. AFM measurements show the softness of non-irradiated thin films. The obtained results show that the agarose films' surface properties are considerably changed by the laser-induced structuring. Higher contact angles indicate an important reduction in wettability being a consequence of the laser grating's enhanced surface roughness. Measured contact angles and free surface energy of patterning thin film show alterations in surface wettability.