Open Access Nano Express

Monolithic carbon structures including suspended single nanowires and nanomeshes as a sensor platform

Yeongjin Lim1, Jeong-Il Heo1, Marc Madou23 and Heungjoo Shin12*

Author affiliations

1 School of Mechanical and Advanced Materials Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea

2 School of Nano-Bioscience and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea

3 Department of Mechanical and Aerospace Engineering, University of California-Irvine, Irvine, CA 92697, USA

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Citation and License

Nanoscale Research Letters 2013, 8:492  doi:10.1186/1556-276X-8-492

Published: 20 November 2013

Abstract

With the development of nanomaterial-based nanodevices, it became inevitable to develop cost-effective and simple nanofabrication technologies enabling the formation of nanomaterial assembly in a controllable manner. Herein, we present suspended monolithic carbon single nanowires and nanomeshes bridging two bulk carbon posts, fabricated in a designed manner using two successive UV exposure steps and a single pyrolysis step. The pyrolysis step is accompanied with a significant volume reduction, resulting in the shrinkage of micro-sized photoresist structures into nanoscale carbon structures. Even with the significant elongation of the suspended carbon nanowire induced by the volume reduction of the bulk carbon posts, the resultant tensional stress along the nanowire is not significant but grows along the wire thickness; this tensional stress gradient and the bent supports of the bridge-like carbon nanowire enhance structural robustness and alleviate the stiction problem that suspended nanostructures frequently experience. The feasibility of the suspended carbon nanostructures as a sensor platform was demonstrated by testing its electrochemical behavior, conductivity-temperature relationship, and hydrogen gas sensing capability.

Keywords:
Suspended carbon nanostructure; Pyrolysis; C-MEMS; Nanomesh