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Nano- and hetero-structures of carbon nanotube (CNT) and indium tin oxide (ITO) can control significantly piezoelectric
and optoelectronic properties in Microelectromechanical Systems (MEMS) as sensing and actuator under cyclic loading.
Optimized preparing conditions were obtained for multi-functional purpose of the specimen by obtaining the best
dispersion and turbidity in the solution. Optical transmittance and electrical properties were investigated for CNT and
ITO dipping and spraying coating on boro-silicate glass and polyethylene terephthalate (PET) substrates by electrical
resistance measurement under cyclic loading and wettability test. Uniform dip-coating was performed using Wilhelmy
plate method due to its simple and convenience. Spraying coating was applied to the specimen additionally. The change
in the electrical resistance and optical properties of coated layer were mainly dependent upon the number of dip-coating,
the concentration of CNT and ITO solutions, and the surface treatment condition. Electric properties of coating layers
were measured using four-point probe method, and surface resistance was calculated using a dual configuration method.
Optical transmittance of CNT and ITO coated PET film was also evaluated using UV spectrum. Surface energy and their
hydrophilic and hydrophobic properties of CNT and ITO coated substrates were investigated by wettability test via static
and dynamic contact angle measurements. As the elapsing time of cyclic loading passed, the stability of surface
resistance and thus comparative interfacial adhesion between coated layer and substrates was evaluated to compare the
thermodynamic work of adhesion, Wa. As dip-coating number increased, surface resistance of coated CNT decreased,
whereas the transmittance decreased step-by-step due to the thicker CNT and ITO networked layer. Nano- and heterostructural
effects of CNT and ITO solution on the optical and electrical effects have been studied continuously.
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