The study of growing CNTs with specific structure using the intelligent control MPCVD system

In order to improve the reproducibility of mutiwalled carbon nano-tubes (MWCNTs) process, this study integrates the remote monitoring and fuzzy logic control into microwave plasma chemical vapor deposition (MPCVD) system with the reflected microwave power as the main feedback signal. An automatic fuzzy logic controller is used to drive the E-H tuner and adjust the electromagnetic field distribution and plasma density of the MPCVD system. The specific micro-structure ratio of MWCNTs is a fuzzy singleton which input into fuzzy logic algorithm. An E-H tuner position adjustment of (X, Y) = (19.3 cm, 10 cm) is found to have the lowest average reflected power. At this position, the MWCNTs with averaged films thickness is 15.44 μm, the averaged tube diameter is 42 nm, and the I_D/I_G ratio is 1.12 for as-grown carbon nanotubes (CNTs) film.