Tunable effective permittivity of carbon nanotube composites

Composites with carbon nanotubes (CNTs) as inclusions were prepared and the dielectric properties under bias voltages were studied. It was found that the composites with weight concentrations of CNTs above 6 wt % exhibited tunable dielectric characteristics under an external applied bias voltage with real part decreasing while the imaginary part increases with the increasing applied voltage. The tunable properties may be understood from the percolation threshold point of view. Potential applications of such tunable properties of the CNTs composites include smart materials and structures.