Properties of electrophoretically deposited single wall carbon nanotube films

• We explain the electrophoretic deposition process and mechanism of thin SWCNT film deposition.
• Characterization of the SWCNT film properties including density, resistivity, transmittance, and Young's modulus.
• The film density and resistivity are found to be a function of the film thickness.
• Techniques developed to create free standing layers of SW-CNTs for flexible electronics and mechanical actuators.

This paper describes techniques for rapidly producing a carbon nanotube thin film by electrophoretic deposition at room temperature and determines the film mass density and electrical/mechanical properties of such films. The mechanism of electrophoretic deposition of thin layers is explained with experimental data. Also, film thickness is measured as a function of time, electrical field and suspension concentration. We use Rutherford backscattering spectroscopy to determine the film mass density. Films created in this manner have a resistivity of 2.14 × 10− 3 Ω·cm, a mass density that varies with thickness from 0.12 to 0.54 g/cm3, and a Young's modulus between 4.72 and 5.67 GPa. The latter was found to be independent of thickness from 77 to 134 nm. We also report on fabricating free-standing films by removing the metal seed layer under the CNT film, and selectively etching a sacrificial layer. This method could be extended to flexible photovoltaic devices or high frequency RF MEMS devices.