Adhesion characteristics of carbon nanotube gecko tapes for micrometer-sized particles

ABSTRACT

A detailed understanding of the adhesive properties of a carbon nanotube (CNT)-based gecko tape with respect to microscale particles is necessary for its practical application as a supporting medium for specific solid materials. We obtained the force curves of vertically aligned CNTs (VACNTs) for individual microparticles of various diameters using atomic force microscopy and evaluated their adhesion force and adhesion length. The measured adhesive force followed the apparent contact area with increasing embedding depth and was size-dependent at scales of several tens of micrometers. The adhesive forces measured for a 20 µm-diameter bead was significantly higher than those for larger particles, which may be related to inclination of the adherent surface against the VACNT tape surface. The adhesion length depended on the type of the CNTs comprising the VACNT, rather than on the bead size. The evaluation of VACNTs with different morphologies suggested that the flexibility of the individual CNTs and the density of the CNT – CNT interconnections in the VACNTs were important factors for obtaining the true contact area to realize better adhesion of micrometer-sized particles.

KEYWORDS:

• Gecko tape
• carbon nanotube
• atomic force microscopy
• adhesion by physical adsorption
• structure property relationship

Acknowledgments

The authors would like to thank Masayuki Uesugi (JASRI), Motoo Ito (JAMSTEC), and all the members of the Phase 2 Curation Team Kochi for their practical advice and useful suggestions as specialists in the analysis of extraterrestrial materials. This work was supported by JSPS KAKENHI, Grant Numbers JP20H02029 andJP23H01302. The authors are grateful to Konan Imadate, Kohei Tsujita and Syogo Soraki for their technical support in the preparation of the VACNT samples and AFM measurements.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

All authors contributed to the discussion and interpretation. H.K. synthesized VACNT samples, performed the AFM measurements, and analyzed the data. K.H. conceived the idea, designed the project, and supervised H. K in experimentation and writing of this manuscript.

Data availability statement

The raw/processed data required to reproduce these findings cannot be shared at this time as the data also forms a part of an ongoing study.

Additional information

Funding

The work was supported by the Japan Society for the Promotion of Science [JP20H02029, JP23H01302].