• DOI:10.1039/c5nr03215f
• Corpus ID: 3485703

Suspended single-walled carbon nanotube fluidic sensors.

@article{Son2015SuspendedSC,
  title={Suspended single-walled carbon nanotube fluidic sensors.},
  author={Byung Hee Son and Ji-Yong Park and Soonil Lee and Yeong Hwan Ahn},
  journal={Nanoscale},
  year={2015},
  volume={7 37},
  pages={
          15421-6
        }
}

• B. Son, Ji-Yong Park, +1 author Y. Ahn
• Published 21 September 2015
• Physics
• Nanoscale

In this paper, we demonstrate the fabrication of liquid flow sensors employing partially suspended single-walled carbon nanotubes (SWNTs). We have found that the sign of the conductance change in SWNT flow sensors is not influenced by the direction of water flow for both supported and suspended devices. Therefore, the streaming potential is not the principal mechanism of the SWNT sensor response. Instead, the conductance change is more likely due to a reduction in the cation density in the electrical double layer, whose equilibrium conditions are determined by the liquid flow rate. More importantly, we have found that the sensitivity of suspended SWNT devices is more than 10 times greater than that of supported SWNT devices. A reduced screening effect and an increase in effective sensing volume are responsible for the enhanced sensitivity, which is consistent with the ion depletion model. We also have measured conductance as a function of gate bias at different flow rates and have determined the flow-rate dependent effective charge density, which influences the electrostatic configuration around SWNT devices.