Keywords: carbon nanotubes, suspended nanotubes, nanotube transistors, immersion in fluids, liquids, nanotube fabrication, nanosensors, nanotechnology, bioelectronics
Fabrication and characterisation of suspended carbon nanotube devices in liquid
Suspended carbon nanotube devices represent a promising platform for future bio-electronic applications. Suspended carbon nanotube transistors have been previously fabricated in air; however all previous attempts to bring them into liquid failed. We analyse forces acting on the suspended nanotube devices during immersion into liquids and during device operation and show that surface tension forces acting on the suspended nanotubes during transfer into the liquid phase are responsible for the nanotube damage. We have developed a new strategy that circumvents these limitations by coating suspended nanotubes with a rigid inorganic shell in the gas phase. The coating reinforces the nanotubes and allows them to survive transfer through the interface. Subsequent removal of the coating in the solution phase restores pristine suspended nanotubes. We demonstrate that devices fabricated using this technique preserve their original electrical characteristics.