Pitcher plant-bioinspired bubble slippery surface fabricated by femtosecond laser for buoyancy-driven bubble self-transport and efficient gas capture

Abstract

Functional materials with specific bubble wettability play an important role in manipulating the behavior of underwater gas bubbles. Inspired by the natural Pitcher plant, we designed a large area lubricated slippery surface (LSS) by femtosecond laser processing for buoyancy-driven bubble self-transport and efficient gas capture. The mechanism of bubble self-transport involves a competition between the buoyancy and the resistance due to drag force and hysteresis. The transportation velocity of the bubbles on the LSS is strongly associated with the surface tension of the lubricants. The lower the surface tension, the higher the sliding velocity. On the basis of sufficient bubble adhesion, the shaped LSS tracks are fabricated to guide the bubble movement and achieve continuous manipulation between bubble merging and detachment. We demonstrate that these designable pathways on the LSS not only manipulate bubble behavior in a two-dimensional space but also realize three-dimensional movement of bubbles on the Mobius-striped LSS. Finally, a gas catcher decorated with large area LSS is manufactured for underwater bubble capture, which maintains a high capture efficiency (more than 90%) with an air output of ∼3.4 L min⁻¹. This finding reveals a meaningful interaction between the underwater bubbles and the LSS surface, accelerating the applications of bubble slippery surfaces in underwater flammable gas collection and tail gas treatment.