How to adjust bubble's adhesion on solid in aqueous media: Femtosecond laser-ablated patterned shape-memory polymer surfaces to achieve bubble multi-manipulation

Manipulation of the behaviour of gas bubbles in aqueous environment is of vital significance in medical and microfluidic fields, and has attracted much research attention in the past few years. Making clear the interrelation between underwater bubbles’ wettability and the solid surfaces topography to achieve the bubble adhesion regulation is a crucial factor of realizing the precise bubble manipulation without external stimulation, and a great challenge. Here, by combining the fish-scale-like morphology and rose-petal-like morphology into one sample and changing the proportion of each part, the underwater bubble adhesion could be adjusted from ultralow to low, high, and ultrahigh. The square-patterned array shape-memory polymer (SMP) surfaces with various adhesion forces were fabricated by femtosecond laser ablation and used to realize lossless transportation of a bubble in both horizontal and vertical direction. The high adhesion surface could be used to form programmable microbubble patterns. By taking advantage of the excellent thermal shape-memory character of SMP film, we realized the bubble in-situ release and reversely switch of the bubble adhesion based on the macroscopic and microscopic deforming-recovering of as-prepared SMP sample. The present study will inspire people to develop novel strategies to achieve multi-manipulation of bubbles in practical applications.