Non-contact measurement of CNT compounding ratio in composite material by eddy current method

Carbon nano-tubes (CNT) are new materials which have an excellent mechanical and electric characteristics. Electric conductivity and high rigidity (high strength) can be given to a resin by mixing CNT with a usual resin. The compounding ratio of CNT was estimated by optical observation and resistance measurement by 4 probes method so far. But, both methods are time-consuming. Therefore, the resistivity of the composite material was measured with non-contact using the eddy current method that used the differential probe coil, and the method of estimating the compounding ratio was applied in this study.