Integrating graphene onto three-dimensional (3D) microelectrodes is a plausible technique to significantly improve the sensitivity of electrochemical devices. However, the construction of graphene coated 3D microstructures has been a considerable challenge. In this paper, we present a simple methodology using electrostatic spray deposition (ESD) to conformally coat graphene onto 3D carbon micropillars that are fabricated by pyrolyzing finely patterned photoresist. During the ESD, changes in the critical parameters such as substrate temperature, deposition time, and nozzle to substrate distance have shown a significant effect on the morphology of the deposited graphene film. The amperometric response of graphene/carbon micropillar electrode arrays exhibited higher electrochemical activity, improved charge transfer and a linear response towards H(2)O(2) detection between 250 μM and 5.5 mM. The ESD technique, with the flexibility of integrating a wide variety of functional nanomaterials onto complex 3D microstructures, is attractive in the field of electrochemistry and biotechnology.

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High-throughput synthesis of carbon nanostructures with reproducible shape and dimensions, at desired locations, has been a key challenge for further exploring carbon nanostructures as functional units in various nanodevices. In this work, carbon structures with dimensions from the 50 nano-to micrometer level have been fabricated by carbonizing a photo-nanoimprint lithography patterned resist polymer (AR-UL-01) at high temperature under inert atmosphere. The resulting carbon nanostructures showed significant vertical shrinkage but minimal loss in the lateral direction. Thermal behavior studies of the resist polymer in the pyrolysis cycle indicated gaseous evolution of various byproducts before the formation of solid carbon. Microstructure, elemental composition and resistivity characterization of the nanostructures produced by this process has shown that the carbon derived from a pyrolyzed nanoimprint resist is very similar to the pyrolyzed photoresist carbon from an SU-8 negative-tone photoresist. This simple approach is valuable as a wafer-level carbon nano-patterning technique.

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