We present a new and simple method to produce superhydrophobic surfaces with ultralow hysteresis. The method involves surface modification of SU-8 using an excimer laser treatment. The modified surface is coated with a hydrophobic plasma-polymerized hexafluoropropene layer. The advancing and receding water contact angles were measured to be approximately 165 degrees . The achieved water contact angle hysteresis was below the measurement limit. This low hysteresis can be ascribed to nanoscale debris generated during the excimer laser process.

We studied the deformation and destabilization of thin liquid films on stationary substrates via infrared illumination. The film thickness evolution was measured using interference microscopy. We developed numerical models for the temperature evolution and the liquid redistribution. The substrate wettability is explicitly accounted for via a phenomenological expression for the disjoining pressure. We systematically measured the film thinning- and rupture dynamics as a function of laser power, which are accurately reproduced by the simulations. While smaller laser spots generally lead to shorter rupture times, the latter can become independent of the spotsize for very narrow beams due to capillary suppression.

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