Tribology Letters

, Volume 49, Issue 1, pp 169–178 | Cite as

Self-lubricating SU-8 Nanocomposites for Microelectromechanical Systems Applications

  • Prabakaran Saravanan
  • Nalam Satyanarayana
  • Sujeet K. Sinha
Original Paper


SU-8 is an industrially useful photoresist polymer for micro-fabrication because of its unique UV-sensitive curing property. It is also used as a structural material for micro-machines such as micro-electro mechanical systems (MEMS). However, it has poor tribological and mechanical properties which make SU-8 inferior to Si, the mainstay MEMS material today. In this paper, we report the fabrication of SU-8 nanocomposites which are self-lubricating and have better mechanical properties. The liquid lubricant i.e., perfluoropolyether (PFPE) and nanoparticles such as SiO2, CNTs, and graphite were added into SU-8 for this purpose. These self-lubricating SU-8 + PFPE and SU-8 + PFPE + nanoparticle composites have shown a reduction in the initial coefficient of friction by ~6–9 times and increased wear life by more than four orders of magnitude. The mechanical properties such as the elastic modulus and the hardness have increased by ~1.4 times. These SU-8 nanocomposites can be used as a self-lubricating structural material for MEMS applications requiring no external lubrication. As well, these nanocomposites can find applications in many tribological components of traditional machines.


Lubrication Polymer Self-lubrication MEMS 



This research is supported by the Singapore National Research Foundation under its CRP (Competitive Research Program) funding (Award Number: NRF-CRP 2-2007-04). The views expressed herein are those of the authors and are not necessarily those of the Singapore National Research Foundation. Part of the results presented here has been filed for US Provisional Patent Application No.: 61/563,522, Filing date: 23 November 2011 (Inventors: S. K. Sinha, Prabakaran Saravanan, and N. Satyanarayana).


  1. 1.
    Marinis, T.F.: The future of microelectromechanical systems (MEMS). Strain 45, 208–220 (2009)CrossRefGoogle Scholar
  2. 2.
    Kim, S.H., Asay, D.B., Dugger, M.T.: Nanotribology and MEMS. NanoToday 2, 22–29 (2007)Google Scholar
  3. 3.
    de Boer, M.P., Mayer, T.M.: Tribology of MEMS. MRS Bull. 4, 302–304 (2001)CrossRefGoogle Scholar
  4. 4.
    Lee, K.K., Bhushan, B., Hansford, D.: Nanotribological characterization of fluoropolymer thin films for biomedical micro/nanoelectromechanical system applications. J. Vac. Sci. Technol. A 23, 804–810 (2005)CrossRefGoogle Scholar
  5. 5.
    Gelorme, J.D., Cox, R.J., Gutierrez, S.A.R.: Photoresist composition and printed circuit boards and packages made herewith. US Patent 4,882,245, 21 Nov 1989Google Scholar
  6. 6.
    Abgrall, P., Conedera, V., Camon, H., Gue, A.-M., Nguyen, N.T.: SU-8 as a structural material for labs-on-chips and microelectromechanical systems. Electrophoresis 28, 4539–4551 (2007)CrossRefGoogle Scholar
  7. 7.
    Asay, D.B., Dugger, M.T., Ohlhausen, J.A., Kim, S.H.: Macro- to nanoscale wear prevention via molecular adsorption. Langmuir 24, 155–159 (2008)CrossRefGoogle Scholar
  8. 8.
    Asay, D.B., Dugger, M.T., Kim, S.H.: In situ vapor-phase lubrication of MEMS. Tribol. Lett. 29, 67–74 (2008)CrossRefGoogle Scholar
  9. 9.
    Eapen, K.C., Patton, S.T., Smallwood, S.A., Philips, B.S., Zabinski, J.S.: MEMS lubricants based on bound and mobile phases of hydrocarbon compounds: film deposition and performance evaluation. J. Microelectromech. Syst. 14, 954–960 (2005)CrossRefGoogle Scholar
  10. 10.
    Henck, S.A.: Lubrication of digital micromirror devices™. Tribol. Lett. 3, 239–247 (1997)CrossRefGoogle Scholar
  11. 11.
    Knieling, T., Lang, W., Benecke, W.: Gas phase hydrophobisation of MEMS silicon structures with self-assembling monolayers for avoiding in-use sticking. Sens. Actuators B 126, 13–17 (2007)CrossRefGoogle Scholar
  12. 12.
    Ma, J.Q., Pang, C.J., Mo, Y.F., Bai, M.W.: Preparation and tribological properties of multiply-alkylated cyclopentane (MAC)-octadecyltrichlorosilane (OTS) double-layer film on silicon. Wear 263, 1000–1007 (2007)CrossRefGoogle Scholar
  13. 13.
    Patton, S.T., Eapen, K.C., Zabinski, J.S., Sanders, J.H., Voevodin, A.A.: Lubrication of microelectromechanical systems radio frequency switch contacts using self-assembled monolayers. J. Appl. Phys. 102, 024903 (2007)CrossRefGoogle Scholar
  14. 14.
    Patton, S.T., Slocik, J.M., Campbell, A., Hu, J., Naik, R.R., Voevodin, A.A.: Bimetallic nanoparticles for surface modification and lubrication of MEMS switch contacts. Nanotechnology 19, 405705 (2008)CrossRefGoogle Scholar
  15. 15.
    Prasad, S.V., Scharf, T.W., Kotula, P.G., Michael, J.R., Christenson, T.R.: Application of diamond-like nanocomposite tribological coatings on LIGA microsystem parts. J. Microelectromech. Syst. 18, 695–704 (2009)CrossRefGoogle Scholar
  16. 16.
    Satyanarayana, N., Sinha, S.K.: Tribology of PFPE overcoated self-assembled monolayers deposited on Si surface. J. Phys. D: Appl. Phys. 38, 3512–3522 (2005)CrossRefGoogle Scholar
  17. 17.
    Satyanarayana, N., Sinha, S.K., Lim, S.-C.: Highly wear resistant chemisorbed polar ultra-high-molecular-weight polyethylene thin film on Si surface for micro-system applications. J. Mater. Res. 24, 3331–3337 (2009)CrossRefGoogle Scholar
  18. 18.
    Scharf, T.W., Prasad, S.V., Dugger, M.T., Kotula, P.G., Goeke, R.S., Grubbs, R.K.: Growth, structure, and tribological behavior of atomic layer-deposited tungsten disulphide solid lubricant coatings with applications to MEMS. Acta Mater. 54, 4731–4743 (2006)CrossRefGoogle Scholar
  19. 19.
    Sidorenko, A., Ahn, H.-S., Kim, D.-I., Yang, H., Tsukruk, V.V.: Wear stability of polymer nanocomposite coatings with trilayer architecture. Wear 252, 946–955 (2002)CrossRefGoogle Scholar
  20. 20.
    Jiguet, S., Judelewicz, M., Mischler, S., Hofmann, H., Bertsch, A., Renaud, P.: SU-8 nanocomposite coatings with improved tribological performance for MEMS. Surf. Coat. Technol. 201, 2289–2295 (2006)CrossRefGoogle Scholar
  21. 21.
    Jiguet, S., Judelewicz, M., Mischler, S., Bertch, A., Renaud, P.: Effect of filler behavior on nanocomposite SU8 photoresist for moving micro-parts. Microelectron. Eng. 83, 1273–1276 (2006)CrossRefGoogle Scholar
  22. 22.
    Singh, R.A., Satyanarayana, N., Kustandi, T.S., Sinha, S.K.: Tribo-functionalizing Si and SU8 materials by surface modification for application in MEMS/NEMS actuator-based devices. J. Phys. D: Appl. Phys. 44, 015301 (2011)CrossRefGoogle Scholar
  23. 23.
    Singh, R.A., Satyanarayana, N., Sinha, S.K.: Surface chemical modification for exceptional wear life of MEMS materials. AIP Adv. 1, 042141 (2011)CrossRefGoogle Scholar
  24. 24.
    Voigt, A., Heinrich, M., Martin, C., Liobera, A., Gruetzner, G., Perez-Murano, F.: Improved properties of epoxy nanocomposites for specific applications in the field of MEMS/NEMS. Microelectron. Eng. 84, 1075–1079 (2007)CrossRefGoogle Scholar
  25. 25.
    Chiamori, H.C., Brown, J.W., Adhiprakasha, E.V., Hantsoo, E.T., Straalsund, J.B., Melosh, N.A., Pruitt, B.L.: Suspension of nanoparticles in SU-8: processing and characterization of nanocomposite polymers. Microelectron. J. 39, 228–236 (2008)CrossRefGoogle Scholar
  26. 26.
    Mionic, M., Jiguat, S., Judelewicz, M., Karimi, A., Forro, L., Magrez, A.: Study of the mechanical response of carbon nanotubes-SU8 composites by nanoindentation. Phys. Status Solidi B 247, 3072–3075 (2010)CrossRefGoogle Scholar
  27. 27.
    Okhlopkova, A.A., Pertrova, P.N., Popov, S.N., Fedorov, A.L.: Tribological materials based on polytetrafluoroethylene modified by a liquid lubricant. J. Frict. Wear 29, 133–136 (2008)CrossRefGoogle Scholar
  28. 28.
    Puukilainen, E., Saarenpää, H., Pakkanen, T.A.: Compression-molded, lubricant-treated UHMWPE composites. J. Appl. Polym. Sci. 104, 1762–1768 (2007)CrossRefGoogle Scholar
  29. 29.
    Guo, Q.B., Lau, K.T., Zheng, B.F., Rong, M.Z., Zhang, M.Q.: Imparting ultra-low friction and wear rate to epoxy by the incorporation of microencapsulated lubricant? Macromol. Mater. Eng. 294, 20–24 (2009)CrossRefGoogle Scholar
  30. 30.
    Hu, T., Zhang, Y., Hu, L.: Tribological investigation of MoS2 coatings deposited on the laser textured surface. Wear 278–279, 77–82 (2012)CrossRefGoogle Scholar
  31. 31.
    Neidhardt, J., Hultman, L., Broitman, E., Scharf, T.W., Singer, I.L.: Structural, mechanical and tribological behavior of fullerene-like and amorphous carbon nitride coatings. Diam. Relat. Mater. 13, 1882–1888 (2004)CrossRefGoogle Scholar
  32. 32.
    Sugimoto, I., Miyake, S.: Solid lubricating fluorine-containing polymer film synthesized by perfluoropolyether sputtering. Thin Solid Films 158, 51–60 (1988)CrossRefGoogle Scholar
  33. 33.
    Constantin, F., Fenouillot, F., Pascault, J.-.P., Williams, R.J.J.: Post-crosslinkable blends: reactions between a linear poly(hydroxyl-amino ether) and a diepoxy. Macromol. Mater. Eng. 289, 1027–1032 (2004)CrossRefGoogle Scholar
  34. 34.
    Surface Coatings Association of Australia. (ed.) Surface Coatings: Raw Materials and Their Usage, vol. 1. Chapman & Hall, London (1993). ISBN 0412552108 Google Scholar

Copyright information

© Springer Science+Business Media New York 2012

Authors and Affiliations

  • Prabakaran Saravanan
    • 1
  • Nalam Satyanarayana
    • 1
  • Sujeet K. Sinha
    • 1
  1. 1.Department of Mechanical EngineeringNational University of SingaporeSingaporeSingapore

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