Three-dimensional patterning of solid microstructures through laser reduction of colloidal graphene oxide in liquid-crystalline dispersions

TL;DR

This paper presents a scalable, mask-free laser reduction method to create complex three-dimensional solid microstructures of reduced graphene oxide within liquid-crystalline dispersions, enabling advanced applications in electronics and photonics.

Contribution

It introduces a novel laser-based technique for 3D patterning of graphene oxide structures in liquid crystals without chemicals or masks, operable at ambient conditions.

Findings

Able to produce complex 3D graphene structures with controlled shape.

Structures are mechanically rigid and range from nanometers to millimeters.

Method is scalable, cost-effective, and compatible with existing technologies.

Abstract

Graphene materials and structures have become an essential part of modern electronics and photovoltaics. However, despite many production methods, applications of graphene-based structures are hindered by high costs, lack of scalability and limitations in spatial patterning. Here we fabricate three-dimensional functional solid microstructures of reduced graphene oxide in a lyotropic nematic liquid crystal of graphene oxide flakes using a pulsed near-infrared laser. This reliable, scalable approach is mask-free, does not require special chemical reduction agents, and can be implemented at ambient conditions starting from aqueous graphene oxide flakes. Orientational ordering of graphene oxide flakes in self-assembled liquid-crystalline phases enables laser patterning of complex, three-dimensional reduced graphene oxide structures and colloidal particles, such as trefoil knots, with "frozen" orientational order of flakes. These structures and particles are mechanically rigid and range from hundreds of nanometres to millimetres in size, as needed for applications in colloids, electronics, photonics and display technology.