Facile "scratching" method with common metal objects to generate large-scale catalyst patterns used for growth of single-walled carbon nanotubes

Chemically functionalized surface patterning

Patterning substrates with versatile chemical functionalities from micro- to nanometer scale is a long-standing and interesting topic. This review provides an overview of a range of techniques commonly used for surface patterning. The first section briefly introduces conventional micropatterning tools, such as photolithography and microcontact printing. The second section focuses on the currently used nanolithographic techniques, for example, scanning probe lithography (SPL), and their applications in surface patterning. Their advantages and disadvantages are also demonstrated. In the last section, dip-pen nanolithography (DPN) is emphatically illustrated, with a particular stress on the patterning and applications of biomolecules.

Generation of dual patterns of metal oxide nanomaterials based on seed-mediated selective growth

A facile route for the generation of the dual patterns of metal oxide nanomaterials, for example, ZnO and CuO, has been developed by printing the oxide seeds through a combination of microcontact printing (microCP) and microfluidic (microF) techniques, followed by the simultaneous growth of the two metal oxide nanomaterials in a one-step solution reaction based on hydrothermal, seed-mediated selective growth. The obtained dual patterns of ZnO nanorods and CuO nanoneedles show a sharp boundary between them, indicating well-defined dual-pattern generation. Also, the simultaneous growth of metal oxide nanomaterials is highly material-selective for the specific seeds prepatterned on substrates, resulting in the selective growth of ZnO nanorods and CuO nanoneedles on the ZnO and CuO seeds, respectively. Moreover, the generation of high-quality dual patterns has been similarly realized on a flexible poly(ethylene terephthalate) (PET) wafer. This study demonstrates the well-controlled hydrothermal growth of different metal oxide nanomaterials in the same reaction solution on the preprinted oxide seeds on the target substrates. It opens up an avenue to develop multifunctional devices of different metal oxides with the combination of microCP and microF techniques.