Facile Fabrication of Electrohydrodynamic Micro-/Nanostructures with High Aspect Ratio of a Conducting Polymer for Large-Scale Superhydrophilic/Superhydrophobic Surfaces

This communication describes a straightforward, cost-effective, and contactless lithography technique, electrohydrodynamic patterning, for fabricating the high-aspect-ratio micro-/nanostructures of the conducting polymer (CP) films directly on a conductive substrate with high integrity and throughput. Meanwhile, the superhydrophilicity/superhydrophobicity of the final CP films can be obtained by modulating the ON/OFF-state of the circuit of the assembly in the structure formation process. The final patterned CP films are hydrophilic/superhydrophilic when the circuit of the assembly is ON-state in the structure formation process, while they are hydrophobic/superhydrophobic when the circuit of the assembly is OFF-state. The high-aspect-ratio micro-/nanostructures of the CP films with the superhydrophilic/superhydrophobic surface are important in both fundamental research and practical applications such as photovoltaics, sensors, supercapacitors, actuators, low friction surfaces, and water harvesting.