Skip to main content
Log in

Effect of Chemically Adsorbed Molecules on the Viscous Friction of Nanometer-Thick Liquid Lubricant Films Coated on a Diamond-Like Carbon Surface

  • Original Paper
  • Published:
Tribology Letters Aims and scope Submit manuscript

Abstract

Nanometer-thick liquid lubricant films are used for lubrication of miniaturized mechanical systems such as hard disk drives and microelectromechanical systems. In particular at the head–disk interface of hard disk drives, the lubricant thin film is coated on a diamond-like carbon surface, and the films are usually composed of both chemically and physically adsorbed lubricant molecules. The combination of these two types of molecules leads to high lubrication performance. However, the detailed mechanism is not fully understood. The aim of this study was to clarify the effect of chemically adsorbed lubricant molecules on the viscous friction of lubricant films. Two different samples were tested: One was the lubricant film composed of both chemically and physically adsorbed molecules, and the other was the lubricant film with only physically adsorbed molecules. We used a fiber wobbling method (FWM), which we developed in our previous study, to measure the viscous friction. The FWM uses a spherical-ended glass fiber as a shearing probe and enables friction forces in the order of 0.1 nN to be measured at precisely controlled nanometer-scale gap widths. For the fair comparison of friction forces between the samples with different compositions, the contact area between the probe tip and the lubricant film must be the same. To determine the contact area in the friction measurement, we improved the FWM system to enable simultaneous measurement of friction force and contact area. Experimental results showed the 1-nm-thick layer of chemically adsorbed molecules in the lubricant film effectively reduced the viscous friction.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  1. Rymuza, Z.: Control tribological and mechanical properties of MEMS surfaces. Part 1: critical review. Microsyst. Technol. 5(4), 173–180 (1999)

    Article  Google Scholar 

  2. Eapen, K.C., Patton, S.T., Zabinski, J.S.: Lubrication of microelectromechanical systems (MEMS) using bound and mobile phases of Fomblin Zdol®. Tribol. Lett. 12(1), 35–41 (2002)

    Article  Google Scholar 

  3. Gui, J.: Tribology challenges for head–disk interface toward 1Tb/in2. IEEE Trans. Magn. 39(2), 716–721 (2003)

    Article  Google Scholar 

  4. Marchon, B., Pitchford, T., Hsia, Y.-T., Gangopadhyay, S.: The head–disk interface roadmap to an areal density of Tbit/in2. Adv. Tribol. 2013(521086), 1–8 (2013)

    Google Scholar 

  5. Zhao, Z., Bhushan, B.: Effect of bonded lubricant films on the tribological performance of magnetic thin-film rigid disks. Wear 202(1), 50–59 (1996)

    Article  Google Scholar 

  6. Chen, C.-Y., Bogy, D., Bhatia, C.S.: Effect of lubricant bonding fraction at the head–disk interface. Tribol. Lett. 10(4), 195–201 (2001)

    Article  Google Scholar 

  7. Junho, C., Kawaguchi, M., Kato, T.: The surface coverage effect on the frictional properties of patterned PFPE nanolubricant films in HDI. IEEE Trans. Magn. 39(5), 2492–2494 (2003)

    Article  Google Scholar 

  8. Zhang, H., Mitsuya, Y., Fujikawa, Y., Fuwa, A., He, Y., Fukuzawa, K.: Changes in friction properties of monolayer lubricant films induced by development of molecules’ bonding. Tribol. Lett. 28(2), 163–170 (2007)

    Article  Google Scholar 

  9. Hedong, Z., Mitsuya, Y., Fuwa, A., Fujikawa, Y., Fukuzawa, K.: Effect of thermal bonding on frictional properties of monolayer lubricant films coated on magnetic disk surfaces. IEEE Trans. Magn. 44(11), 3637–3640 (2008)

    Article  Google Scholar 

  10. Lu, R., Zhang, H., Mitsuya, Y., Fukuzawa, K., Itoh, S.: Contributions of mobile and bonded molecules to dynamic friction of nanometer-thick perfluoropolyether films coated on magnetic disk surfaces. Tribol. Lett. 54(3), 237–247 (2013)

    Article  Google Scholar 

  11. Itoh, S., Fukuzawa, K., Hamamoto, Y., Zhang, H.D., Mitsuya, Y.: Fiber wobbling method for dynamic viscoelastic measurement of liquid lubricant confined in molecularly narrow gaps. Tribol. Lett. 30(3), 177–189 (2008)

    Article  Google Scholar 

  12. Itoh, S., Fukuzawa, K., Takahashi, K., Ando, T., Zhang, H., Mitsuya, Y.: Optimization of dynamic shear force measurement for fiber wobbling method. Microsyst. Technol. 11(8–10), 894–900 (2005)

    Article  Google Scholar 

  13. Itoh, S., Ishii, K., Fukuzawa, K., Zhang, H.: Shear thinning of nanometer-thick liquid lubricant films measured at high shear rates. Tribol. Lett. 53(3), 555–567 (2014)

    Article  Google Scholar 

  14. Fukuzawa, K., Itoh, S., Suzuki, K., Kawai, Y., Zhang, H., Mitsuya, Y.: Diffusive motion of molecules in submonolayer liquid films on a solid surface. Phys. Rev. E 72(6), 061602 (2005)

    Article  Google Scholar 

  15. Itoh, S., Takahashi, K., Fukuzawa, K., Amakawa, H., Zhang, H.: Spreading properties of monolayer lubricant films: effect of bonded molecules. IEEE Trans. Magn. 45(11), 5055–5060 (2009)

    Article  Google Scholar 

  16. Itoh, S., Hamamoto, Y., Ishii, K., Fukuzawa, K., Zhang, H.D.: Detection of asperity contact for precise gap determination in thin-film nanorheometry. Tribol. Lett. 49(1), 1–10 (2013)

    Article  Google Scholar 

  17. Vurens, G.H., Gudeman, C.S., Lin, L.J., Foster, J.S.: The mechanism of ultraviolet bonding of perfluoropolyether lubricants (used in magnetic recording). IEEE Trans. Magn. 29(1), 282–285 (1993)

    Article  Google Scholar 

  18. Tyndall, G.W., Waltman, R.J., Pocker, D.J.: Concerning the interactions between Zdol perfluoropolyether lubricant and an amorphous-nitrogenated carbon surface. Langmuir 14(26), 7527–7536 (1998)

    Article  Google Scholar 

  19. Waltman, R.J., Pocker, D.J., Tyndall, G.W.: Studies on the interactions between ZDOL perfluoropolyether lubricant and the carbon overcoat of rigid magnetic media. Tribol. Lett. 4(3/4), 267–275 (1998)

    Article  Google Scholar 

  20. Chiba, H., Takeda, M., Nakamura, N., Watanabe, K.: Improvements of lubricant performance in hard-disk media by vacuum ultraviolet irradiation. Tribol. Int. 36(4–6), 367–369 (2003)

    Article  Google Scholar 

  21. Zhang, H., Mitsuya, Y., Imamura, M., Fukuoka, N., Fukuzawa, K.: Effect of ultraviolet irradiation on the interactions between perfluoropolyether lubricant and magnetic disk surfaces. Tribol. Lett. 20(3–4), 191–199 (2005)

    Article  Google Scholar 

  22. Gennes, P.-G.D., Brochard-Wyart, F., Quere, D.: Capillarity and wetting phenomena: drops, bubbles, pearls, waves. Springer, New York (2003)

    Google Scholar 

  23. Luengo, G., Israelachvili, J., Granick, S.: Generalized effects in confined fluids: new friction map for boundary lubrication. Wear 200(1–2), 328–335 (1996)

    Article  Google Scholar 

  24. Ruths, M., Granick, S.: Tribology of confined Fomblin-Z perfluoropolyalkylethers: molecular weight dependence and comparison between unfunctionalized and telechelic chains. Tribol. Lett. 7(4), 161–172 (1999)

    Article  Google Scholar 

  25. Yamada, S.: General shear-thinning dynamics of confined fluids. Tribol. Lett. 13(3), 167–171 (2002)

    Article  Google Scholar 

  26. Pit, R., Hervet, H., Leger, L.: Direct experimental evidence of slip in hexadecane: solid interfaces. Phys. Rev. Lett. 85(5), 980–983 (2000)

    Article  Google Scholar 

Download references

Acknowledgments

The present research was partially supported by the Storage Research Consortium and the Asahi Glass Foundation.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Shintaro Itoh.

Additional information

This article is part of the Topical Collection on STLE Tribology Frontiers Conference 2014.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Itoh, S., Norizuki, Y., Fukuzawa, K. et al. Effect of Chemically Adsorbed Molecules on the Viscous Friction of Nanometer-Thick Liquid Lubricant Films Coated on a Diamond-Like Carbon Surface. Tribol Lett 60, 7 (2015). https://doi.org/10.1007/s11249-015-0583-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11249-015-0583-5

Keywords

Navigation