Carbon nanotubes grown on polyimide by chemical vapour deposition

Carbon nanotubes grown on polyimide by chemical vapour deposition
Schneider K, Stamm B, Gutohrlein K, Fleischer M, Burkhardt C, Stett A, Kern D
Nanotechnology (IEEE-NANO), 2012 12th IEEE Conference on.

Carbon nanotubes (CNTs) are ideal candidates as electrode materials for neuronal stimulation and monitoring devices, since they provide a high charge injection limit without significant Faradic reactions, and carbon nanotube electrodes have a high surface to volume ratio. CNTs are positioned at desired locations by chemical vapour deposition (CVD) growth from patterned catalysts. However, these processes typically require temperatures above 700 °C, which is unacceptable for many flexible substrate materials like polyimide, which looses its insulating properties around 400 °C and its stability at 600 °C. By proper selection of parameters such as catalyst material, gas composition, processing pressure and time, it is possible to grow CNTs at temperatures as low as 350 °C with a total CNT height of ∼1 µm on silicon. On polyimide additional substrate and catalyst pretreatment is necessary at such low temperatures. This indicates that the substrate may influence the growth process of CNTs.