Measurement of thermal conductivity of thin and thick films based on micropipette thermocouple

This paper describes novel glass micropipette thermal sensor fabricated in a cost-effective manner and thermal conductivity measurement of carbon nanotubes (CNT) thin film using the developed sensor. Various micrometer-sized sensors, which range from 2 μm to 30 μm, were produced and tested. The capability of the sensor in measuring thermal fluctuation at micro level with an accuracy of ±0.01°C is demonstrated. The sensitivity of sensors was recorded from 3.34 to 8.86 μV/°C, which was independent of tip size and dependent on the coating of Nickel. The experimental approach that was used for thermal conductivity measurement of CNT film is relevant to steady-state temperature distribution along the radial direction of the CNT film subject to continuous wave laser irradiation. We have obtained reproducible thermal conductivity data using various micropipette temperature sensors. The average thermal conductivity of the CNT film at room temperature was determined at 73.4 W/m°C.