The Research Of Transfer And Adhesion Performance Of Carbon Nanotubes Array

The micro-nano scale beta-keratin pillars contribute to the gecko’s superior climbing ability onvertical walls and even ceilings. Design and preparation of gecko-mimicking dry adhesive arrays areimportant for the development of wall climbing robots. Hence here, we focus on developing carbonnanotubes arrays dry adheisves and studying their adhesion performance. In this paper, three criticalaspects of carbon nanotubes dry adhesives are investigated.The aligned carbon nanotubes arrays were synthetized by catalytic chemical vapor deposition(CCVD) in growth tepreature of750℃, acttylene used as carbon source, Fe ion as catalyst. The SEMresults show that the grown CNTs have well-aligned structure.With thermoplastic polyurethanes (TPU) in concentration of20%as a transfer medium, as-grownCNTs of different sizes were transferred directly onto a wide range of versatile substrates after curing60~90min in temperature of70℃. The SEM and Raman results show that the structure of transferredCNTs remains intact; the distribution of the top layer of transferred CNTs becomes much denser. Thenormal adhesive strength of CNTs transferred onto PET, Cu and Al substrates increase from0.2kPa to17.3kPa,14.7kPa and13.4kPa, shear adhesive strength increase from26.1kPa to75.3k Pa,81.8k Paand85.8k Pa, respectively.The adhesion test results show that the CNTs have a normal adhesive strength for6N/cm~2whenapplied a normal force of4500mN with a shear displacement of0.2mm; a shear adhesive strength for26N/cm~2when applied a normal force of4500mN with a shear displacement of2mm. The CNTshave good repeatability. When the contact angle is25°, the CNTs have good adhesive performance;when35°, the CNTs can peel off from interface easily. The SEM and Raman results show that there isno obvious damage in the structure of CNTs after normal and shear adhesion test; the distribution ofthe top layer of CNTs becomes much denser. The composite material was prepared to compliment theadhesion performance of the CNTs, PDMS used as matrix, CNTs used as reinforcing phase. Theadhesion test results show that the composite material have a normal adhesive strength for0.5N/cm~2and shear adhesive strength for1.45N/cm~2when applied a normal force of50mN.