SU-8, an epoxy-based negative photoresist polymer, is highly suitable for making micro-electro-mechanical systems (MEMS) structures. Despite fabrication advantages, its bulk mechanical and tribological properties are the main limitations for application as MEMS material. Carbon filler materials such as graphene, graphite and multi-walled carbon nanotube (MWCNT) are added to SU-8 for tribological and mechanical property enhancements. SU-8/(5 wt%) graphite composite has performed better for the steady-state coefficient of friction at all loads including for the speed effect. SU-8/(5 wt%) MWCNT has shown excellent wear resistance. At 10 wt% graphite content, SU-8/graphite is superior in tribological performance to other composites tested.
See various articles in the special issue titled. ‘15 Years of SU-8 as MEMS material’, of Micromachines, 2014–2015 (ISSN 2072-666X).
2.
LauK. H., GiridharA., HarikrishnanS., SatyanarayanaN. and SinhaS. K.: ‘Releasing high aspect ratio SU-8 microstructures using AZ photoresist as a sacrificial layer on metallized Si substrates’, Microsyst. Technol., 2013, 19, 1863–1871.10.1007/s00542-013-1740-0
3.
DeyP. K., PramanickB., RavishankarA., GangulyP. and DasS.: ‘Microstructuring of SU-8 resist for MEMS and bio-applications’, Int. J. Smart Sens. Intell. Syst., 2010, 3, 118–129.
4.
MaboudianR., Robert AshurstW. and CarraroC.: Tribological challenges in micromechanical systems. Tribol. Lett., 2002, 12, 95–100.10.1023/A:1014044207344
5.
SpikesH.: ‘Tribology research in the twenty-first century’, Tribol. Int., 2001, 34, 789–799.10.1016/S0301-679X(01)00079-2
6.
KaajakariV.: ‘Practical MEMS’, Small Gear Publishing; 2009 (ISBN: 0982299109).
7.
JiguetS., JudelewiczM., MischlerS., HofmannH., BertschA. and RenaudP.: ‘SU-8 nanocomposite coatings with improved tribological performance for MEMS’, Surf. Coat. Technol., 2006, 201, 2289–2295.10.1016/j.surfcoat.2006.03.041
8.
JiguetS., JudelewiczM., MischlerS., BertchA. and RenaudP.: ‘Effect of filler behavior on nanocomposite SU8 photoresist for moving micro-parts’, Microelectron. Eng., 2006, 83, 1273–1276.10.1016/j.mee.2006.01.068
9.
JiguetS., BertschA., JudelewiczM., HofmannH. and RenaudP.: ‘SU-8 nanocomposite photoresist with low stress properties for micro-fabrication applications’, Microelectron. Eng., 2006, 83, 1966–1970.10.1016/j.mee.2006.02.004
10.
KimS. H., AsayB. and DuggerM. T.: ‘Nanotribolgy and MEMS’, Nanotoday, 2007, 5, 23–29.
11.
ChiamoriH. C., BrownJ. W., AdhiprakashaE. V., HantsooE. T., StraalsundJ. B., MeloshN. A., and PruittB. L.: ‘Suspension of nanoparticles in SU-8: Processing and characterization of nanocomposite polymers’, Microelectron. J., 2008, 39, 228–236.10.1016/j.mejo.2007.05.012
12.
Al-HalhouliA. T., KampenI. and KrahT.: Bu¨ttgenbach S. Nanoindentation testing of SU-8 photoresist mechanical properties. Microelectron. Eng., 2008, 85, 942–944.10.1016/j.mee.2008.01.033
13.
Mionic’M., JiguetS., JudelewiczM., KarimiA., Forro’L. and MagrezA.: Study of the mechanical response of carbon nanotubes-SU8 composites by nanoindentation. Phys. Status Solidi., 2010, B247, 3072–3075.
14.
SinghA. R., SatyanarayanaN. and SinhaS. K.: ‘Surface chemical modification for exceptional wear life of MEMS materials’, AIP Advances, 2011, 1, 042141.10.1063/1.3662096
15.
SaravananP., SatyanarayanaN. and SinhaS. K.: ‘Self-lubricating SU-8 nanocomposites for microelectromechanical systems applications’, Tribol. Lett., 2013, 49, 169–178. 10.1007/s11249-012-0055-0
16.
SaravananP., SatyanarayanaN. and SinhaS. K.: ‘Wear durability study on self-lubricating SU-8 composites with perfluoropolyther, multiply-alkylated cyclopentane and base oil as the fillers’, Tribol. Int., 2013, 64, 103–115.10.1016/j.triboint.2013.02.033
17.
SaravananP., SatyanarayanaN., PhuaC. S., DuongH. M. and SinhaS. K.: ‘Tribology of self-lubricating SU-8+PFPE composite based Lub-tapeProcedia Engineering’ MITC; 2013, 68, 497–504.
18.
SaravananP., SatyanarayanaN., DuongH. M. and SinhaS. K.: ‘An in situ heating effect study on tribological behavior of SU-8/PFPE composite’, Wear, 2013, 307, 182–189.10.1016/j.wear.2013.09.001
19.
LahiriD., HecF., ThiesseM., DuryginA., ZhangC. and AgarwalA.: ‘Nanotribological behavior of graphene nanoplatelet reinforced ultra high molecular weight polyethylene composites’, Tribol. Int., 2014, 70, 165–169.10.1016/j.triboint.2013.10.012
20.
PanG., GuoQ., DingJ., ZhangW. and WangX.: ‘Tribological behaviors of graphite/epoxy two-phase composite coatings’, Tribol. Int., 2010, 43, 1318–1325.10.1016/j.triboint.2009.12.068
21.
SamadM. A. and SinhaS. K.: ‘Mechanical, thermal and tribological characterization of a UHMWPE film reinforced with carbon nanotubes coated on steel’, Tribol. Int., 2011, 44, 1932–1941.10.1016/j.triboint.2011.08.001
22.
JacobsO., XuW., SchadelB. and WuW.: ‘Wear behavior of carbon nanotube reinforced epoxy resin composites’, Tribol. Lett., 2006, 23, 65–75.10.1007/s11249-006-9042-7
23.
KumarV., SinhaS. K. and KumarA.: ‘Tribological studies of epoxy and its composite coatings on steel in dry and lubricated sliding’, Tribol. Mater. Surf. Interfaces, 2015, 9, 144–153. doi:10.1179/1751584X15Y.0000000015.
24.
ZhangH., ZhangZ., FriedrichK. and EgerC.: ‘Property improvements of in situ epoxy nanocomposites with reduced interparticle distance at high nanosilica content’, Acta Mater., 2006, 54, 1833–1842.10.1016/j.actamat.2005.12.009
25.
ZhangM. Q., RongM. Z., YuS. L., WetzelB. and FriedrichK.: ‘Improvement of tribological performance of epoxy by the addition of irradiation grafted nano-inorganic particles’, Macromol. Mater. Eng., 2002, 287, 111–115.10.1002/(ISSN)1439-2054
26.
LuoY., RongM. Z. and ZhangM. Q.: ‘Covalently connecting nanoparticles with epoxy matrix and its effect on the improvement of tribological performance of the composites’, Polym. Polym. Compos., 2005, 13, 245–252.
27.
RongM. Z., ZhangM. Q., ShiG., JiQ. L., WetzelB. and FriedrichK.: ‘Graft polymerization onto inorganic nanoparticles and its effect on tribological performance improvement of polymer composites’, Tribol. Int., 2003, 136, 697–707.10.1016/S0301-679X(03)00029-X
28.
McCookN. L., BurrisD. L., BourneG. R., SteffensJ., HanrahanJ. R. and SawyerW. G.: ‘Wear resistant solid lubricant coating made from PTFE and epoxy’, Tribol. Lett., 2005, 18, 119–124.10.1007/s11249-004-1766-7
29.
OwensD. K., WendtR. C.: ‘Estimation of the surface free energy of polymers’, J. Appl. Polym. Sci., 1969, 13, 1741–1747.10.1002/app.1969.070130815
30.
MungseH. P., VermaS., KumarN., SainB. and KhatriO. P.: ‘Grafting of oxo-vanadium Schiff base on graphene nanosheets and its catalytic activity for the oxidation of alcohols’, J. Mater. Chem., 2012, 22, 5427–5433.10.1039/c2jm15644j
31.
ZhangC., ChenM., XuX., ZhangL., ZhangL., XiaF., LiX., LiuY., HuW. and GaoJ.: ‘Graphene oxide reduced and modified by environmentally friendly glycylglycine and its excellent catalytic performance’, Nanotechnology, 2014, 25, 135707 (12 pages).10.1088/0957-4484/25/13/135707
32.
JohnsonK. L.: ‘Contact mechanics’. Cambridge, Cambridge University Press; 1985.
33.
MyintS. M., MinnM., YapingR., SatyanarayanaN., SinhaS. K. and BhatiaC. S.: ‘Friction and wear durability studies on the 3D negative fingerprint and honeycomb textured SU-8 surfaces’, Tribol. Int., 2013, 60, 187–197.10.1016/j.triboint.2012.10.020
34.
TannerD. M., MillerW. M., EatonW. P., IrwinL. W., PetersonK. A., DuggerM. T., SenftD. C., SmithN. F., TangyunyongP. and MillerS. L.: ‘The effect of frequency on the lifetime of a surface micromachined microengine driving a load’, IEEE Int. Reliab. Phys. Symp. Proc., March 30–April 2, 1998, pp. 26–35.
35.
McCookN. L., BurrisD. L., KimN. H., SawyerW. G.: ‘Cumulative damage modeling of solid lubricant coatings that experience wear and interfacial fatigue’, Wear, 2007, 262, 1490–1495.10.1016/j.wear.2007.01.042
36.
BriscoeB. J., EvansD. C. B.: ‘The shear properties of Langmuir–Blodgett layers’, Proc. R. Soc. London. A., 1982, 380, 389–407.10.1098/rspa.1982.0048
