Anisotropic Sliding of Underwater Bubbles On Microgrooved Slippery Surfaces by One-Step Femtosecond Laser Scanning

Slippery liquid-infused surfaces (SLIPS) with excellent liquid sliding abilities have attracted great attention due to their multifunctions in broad fields. However, current research is mainly concentrated on the isotropic SLIPS, and there are few studies about the fabrication of anisotropic SLIPS and the investigation of anisotropic bubble sliding. Herein, we reported a kind of distinct periodic microgrooved slippery surface (MGSS) by one-step femtosecond laser scanning and realized bubble anisotropic sliding in a liquid system. The MGSS enables the bubble to slide along the direction of grooves but prevents the bubble from sliding along the perpendicular direction to the groove. The mechanism is mainly related to the energy barrier difference caused by the spin-coating oil film thickness and the groove height along the parallel and perpendicular directions. The relationship between the driven force of buoyancy and the resistance of contact angle hysteresis was investigated by theoretical analysis, and t...