Direct‐Writing of Multi‐Functional Photo‐Reduced Graphene Oxide Fabric (rGOf) at the Liquid‐Air Interface with Tunable Porosity

Abstract A multi‐functional photo‐reduced graphene oxide fabric (rGOf) created through a laser direct‐write technique at the solution surface is presented. Taking advantage of the amphiphilic nature of graphene oxide (GO) and the rapid self‐assembly of GO sheets at the liquid‐air interface, a piece of rGOf can be easily produced without any binder or supporting material in an ambient environment. Without any added processing complexity or stringent sample requirements, this accessible technique creates rGOf that exhibits tuneable microscale porosity, which enables efficient surface functionalization and active material coating. Parameters, such as the GO concentration, stabilization time, laser power, printing speed, laser focus, and post‐processing steps, can lead to vastly different rGOf morphologies. The rGOf can be made into self‐standing film or transfer printed onto any desirable substrate. Herein, it is demonstrated that the rGOf platform holds tremendous potential in Joule heating, temperature sensing, humidity sensing, tactile sensing, and ammonia sensing applications.