Improved dynamic stability of superomniphobic surfaces and droplet transport on slippery surfaces by dual-scale re-entrant structures

There has been substantial recent interest with respect to the broad potential applications of superomniphobic surfaces, but it remains enormously challenging to enhance the dynamic stability of such surfaces impacted by high-pressured droplets. Herein, a robust superomniphobic surface with dual-scale re-entrant structures (DRSs) has been designed and fabricated through a facile combination of magnetic particle-assisted self-assembly and a dip-coating technique. Compared to superomniphobic surfaces with single-scale re-entrant structures, this superomniphobic surface with DRSs shows highly improved repellency against the impact from different high-pressured droplets, a property which is furnished by the extension of three-phase contact lines, the increase in local geometric angles, and the formation of additional air pockets. Furthermore, the superomniphobic surface can serve as a platform to well maintain lubricating fluid so as to realize a photoresponsive slippery surface wherein near-infrared light can be used to manipulate various liquid droplets with a large range of volumes. Overall, this study provides a strategy for obtaining the robust superomniphobic and photoresponsive slippery surfaces through the DRS design, which provides a new insight into enhancing the dynamic stability of superomniphobic surfaces and also demonstrates the application of slippery surfaces for droplet manipulation.