Reversible and Programmable Wettability of Laser-Induced Graphene Papers via In Situ Joule Heating-Triggered Superslippery Surfaces

Reversible surface materials with programmable wettability play an increasingly vital role in a wide variety of fields from science to industry. Based on laser-induced graphene (LIG) technology, we innovatively propose a paraffin-infused porous LIG paper (P-LIGP) with tunable superslippery wettability. On account of graphene’s excellent electrical property, paraffin in P-LIGP can transit rapidly from a solid-to-liquid state in response to the in situ Joule heating effect. Thus, a LIGP surface is created with a dynamic and reversible transition between slippery and nonslippery state. In addition, combining the patternable performance with tunable LIGP resistance, the paraffin layer from P-LIGP can be selectively melted based on Ohm’s law and Kirchhoff’s laws, thus enabling special flow pathways with programmable wettability for manipulating the droplets with various straight/oblique/arc/S-shaped sliding patterns. These applications with customizable LIG resistance performance promise the in situ Joule heating of P-LIGP for designing intelligent and flexible temperature-responsive surfaces.