Hydrogenated diamondlike carbon (H-DLC) coatings provide excellent wear resistance and low friction for bearing applications. However, the use of such coatings with aqueous lubricants could pose some difficulties due to the hydrophobic nature of the surface. A thrust bearing tribometer was used to compare performance of hydrophilic and hydrophobic surfaces in hydrodynamic lubrication with a mixture of water and glycerol as the lubricant. Hydrophobic surfaces on both runner and bearing were achieved with the deposition of H-DLC films on titanium alloy surfaces. Hydrophilic surfaces were created through modification of H-DLC surface with covalently bonded heparin. Several possible combinations of hydrophobic and hydrophilic surface conditions were used on the bearing and runner surfaces to provide full-wetting, partial-wetting, and half-wetting conditions. The experimental results confirmed that load support is still possible, when the bearing is half-wetted or partially wetted. However, the full-wetted bearing combination (i.e., Reynolds no-slip boundary condition) provided the highest load support. Introduction of slip at the surface resulted in a lower measured torque. Heparin treatment resulted in a lower than expected static friction and friction in full lubrication regime. The durability of coated surfaces was evaluated in a series of start–stop tests and in impact tests. The results confirmed that the coatings are stable and survive the test regiment that exceeded 50 test cycles; whereas the uncoated titanium alloy bearing surfaces were damaged after ten test cycles.

References

References
1.
Goldstein
,
D. J.
, and
Oz
,
M. C.
, 2000,
Cardiac Assist Devices
,
Futura
,
Armonk, New York
.
2.
Mahmood
,
A. K.
,
Kekhoffs
,
W.
,
Schumacher
,
O.
, and
Reul
,
H.
, 2003, “
Investigation of Materials for Blood-Immersed Bearings in a Microaxial Blood Pump
,”
Artif. Organs
,
27
, pp.
169
173
.
3.
Golding
,
L. A. R.
,
Stewart
,
L. W.
, and
Loop
,
F. D.
, 1989, “
Centrifugal Pumps in Clinical Practice
,”
Assisted Circulation 3
,
F.
Unger
, ed.,
Springer-Verlag
,
Berlin
, pp.
160
166
.
4.
Ren
,
Z.
,
Jahanmir
,
S.
,
Heshmat
,
H.
,
Hunsberger
,
A. Z.
, and
Walton
,
J. F.
, 2009, “
Design Analysis and Performance Assessment of Hybrid Magnetic Bearings for a Rotary Centrifugal Blood Pump
,”
ASAIO J.
,
55
, pp.
340
347
.
5.
Jahanmir
,
S.
,
Hunsberger
,
A. Z.
,
Ren
,
Z.
,
Heshmat
,
H.
,
Heshmat
,
C.
,
Tomaszewski
,
M. J.
, and
Walton
,
J. F.
, 2009 “
Design of a Small Centrifugal Blood Pump With Magnetic Bearing
,”
Artif. Organs
,
33
, pp.
714
726
.
6.
Willis
,
J. P.
,
Locke
,
D. H.
,
Hryniewicz
,
P.
,
Jahanmir
,
S.
,
Heshmat
,
H.
,
Weiss
,
W. J.
,
Lukic
,
B.
,
Pae
,
W. E.
, and
Prophet
,
G. A.
, 2003, “
In Vivo Study of an LVAD Prototype With a Hybrid Magnetic Bearing
,”
ASAIO J.
,
49
, p.
176
.
7.
Ratner
,
B. D.
, 2000, “
Blood Compatibility – A Perspective
,”
J. Biomater Sci., Polym. Ed.
,
11
, pp.
1107
1119
.
8.
Erdemir
,
A.
, 2003,”
Diamond Like Carbon Films
,”
Tribology of Mechanical Systems
,
J.
Vizintin
,
M.
Kalin
K.
Dohda
, and
S.
Jahanmir
, eds.,
ASME
,
New York
, pp.
139
156
.
9.
Gutensohn
,
K.
,
Beythien
,
C.
,
Bau
,
J.
,
Fenner
,
T.
,
Grewe
,
P.
,
Koester
,
R.
,
Padamanaban
,
K.
, and
Kuehn
,
P.
, 2000, “
In Vitro Analysis of Diamond-Like Carbon Coated Stents: Reduction of Metal Ion Release, Platelet Activation, and Thrombogenicity
,”
Thromb. Res.
,
99
, pp.
577
585
.
10.
Steffen
,
H. S.
,
Schmidt
,
J.
, and
Gonzalez-Elipe
,
A.
, 2000, “
Biocompatible Surfaces by Immobilization of Heparin on Diamond-Like Carbon Films Deposited on Various Substrates
,”
Surf. Interface Anal.
,
29
, pp.
386
391
.
11.
Szeri
,
A. Z.
, 1998,
Fluid Film Lubrication
,
Cambridge University
,
Cambridge
.
12.
Craig
,
V. S. J.
,
Neto
,
C.
, and
Williams
,
D. R. M.
, 2001, “
Shear Dependant Boundary Slip in an Aqueous Newtonian Liquid
,”
Phys. Rev. Lett.
,
87
, p.
054504
.
13.
Zhu
,
Y.
, and
Granick
,
S.
, 2001, “
Rate Dependent Slip of Newtonian Liquid at Smooth Surfaces
,”
Phys. Rev. Lett.
,
87
, p.
096105
.
14.
Zhu
,
Y.
, and
Granick
,
S.
, 2002, “
Limits of the Hydrodynamic No-Slip Boundary Conditions
,”
Phys. Rev. Lett.
,
88
, p.
106102
.
15.
Watanabe
,
K.
, and
Udagawa
,
H.
, 1999, “
Drag Reduction of Newtonian Fluid in a Circular Pipe With a Highly Water-Repellent Wall
,”
J. Fluid Mech.
,
381
, pp.
225
238
.
16.
Thompson
,
P. A.
, and
Troian
,
S.
, 1997, “
A General Boundary Condition for Liquid Flow at Solid Surfaces
,”
Nature (London)
,
389
, pp.
360
362
.
17.
Priel
,
S.
, and
Fermeglia
,
M.
, 2001, “
Virtual Rheological Experiments on Linear Alkane Chains Confined Between Titanium Walls
,”
Rheol. Acta
,
40
, pp.
104
110
.
18.
Spikes
,
H. A.
, 2003, “
The Half-Wetted Bearing. Part 1: Extended Reynolds Equation
,”
J. Eng. Tribol.
,
217
, pp.
1
14
.
19.
Spikes
,
H. A.
, 2003, “
The Half-Wetted Bearing. Part 2: Potential Application in MEMs
,”
J. Eng. Tribol.
,
217
, pp.
15
26
.
20.
Pit
,
R.
,
Hervet
,
H.
, and
Leger
,
L.
, 1999, “
Friction and Slip of a Simple Liquid at a Solid Surface
,”
Tribol. Lett.
,
7
, pp.
147
152
.
21.
Hild
,
W.
,
Schaefer
,
J. A
, and
Scherge
,
M.
, 2002, “
Microhydrodunamical Studies of Hydrophilic and Hydrophobic Surfaces
,”
Proceedings of the 13th International Colloquium Tribology
,
W. J.
Bartz
, ed.,
Esslingen
,
Germany
, pp.
821
825
.
22.
Salant
,
R. F.
, and
Fortier
,
A. E.
, 2004, “
Numerical Analysis of a Slider Bearing With a Heterogeneous Slip/No-Slip Surface
,”
Tribol. Trans.
,
47
, pp.
328
334
.
23.
Fortier
,
A. E.
, and
Salant
,
R. F.
, 2005, “
Numerical Analysis of a Journal Bearing With a Heterogeneous Slip/No-Slip Surface
,”
ASME J. Tribol.
,
127
, pp.
820
825
.
24.
Kalin
,
M.
,
Velkavrh
,
I.
, and
Vizintin
,
J.
, 2009, “
The Stribeck Curve and Lubrication Design for Non-Fully Wetted Surfaces
,”
Wear
,
267
, pp.
1232
1240
.
25.
Choo
,
J. H.
,
Glovnea
,
R. P.
,
Forrest
,
A. K.
, and
Spikes
,
H. A.
, 2007, “
A Low Friction Bearing Based on Liquid Slip at the Wall
,”
ASME J. Tribol.
,
129
, pp.
611
620
.
26.
Linneweber
,
J.
,
Dohmen
,
P. M.
,
Kerzscher
,
E.
,
Affeld
,
K.
,
Nose
,
Y.
, and
Konertz
,
W.
, 2007, “
The Effect of Surface Roughness on Activation of the Coagulation System, and Platelet Adhesion in Rotary Blood Pumps
,”
Artif. Organs
,
31
, pp.
345
351
.
27.
Heimberg
,
J. A.
,
Wahl
,
K. J.
,
Singer
,
I. L.
, and
Erdemir
,
A.
, 2001, “
Superlow Friction Behavior of Diamond Like Carbon Coatings: Time and Speed Effects
,”
Appl. Phys. Lett.
,
78
, pp.
2449
2451
.
28.
Sirvio
,
L. M.
, and
Swenson
,
B. C.
, “
Process for Making Polymeric Surfaces Biocompatible for Use in Medical Devices
,” U.S. Patent No. 5, 532, 311.
29.
Anonymous
,
2008, “
Standard Practice for Surface Wettability of Coatings, Substrates and Pigments by Advancing Contact Angle Measurement
,”
ASTM D7334–08
,
ASTM
,
Conshohocken, PA
.
30.
Heshmat
,
H.
, 1992, “
The Quasi-Hydrodynamic Mechanism of Powder Lubrication – Part I: Lubricant Flow Visualization
,”
Lubr. Eng.
,
48
, pp.
96
104
.
31.
Heshmat
,
H.
, 1992, “
The Quasi-Hydrodynamic Mechanism of Powder Lubrication: Part II: Lubricant Film Pressure Profile
,”
Lubr. Eng.
,
48
, pp.
373
383
.
32.
Jahanmir
,
S.
,
Hunsberger
,
A. Z.
,
Heshmat
,
H.
,
Tomaszewski
,
M. J.
,
Walton
,
J. F.
,
Weiss
,
W. J.
,
Lukic
,
B.
,
Pae
,
W. E.
,
Zappanta
,
C. M.
, and
Khalapyan
,
T. Z.
, 2008, “
Performance Characterization of MiTiHeart Rotary Centrifugal LVAD With Magnetic Suspension
,”
Artif. Organs
,
32
, pp.
366
375
.
33.
Hunsberger
,
A. Z.
,
Ren
,
Z.
,
Jahanmir
,
S.
,
Heshmat
,
H.
,
Tomaszewski
,
M. J.
, and
Walton
,
J. F.
, 2007, “
In Vitro Characterization of the Redesigned MiTiHeart LVAD
,”
ASAIO J.
,
53
, p.
32A
.
34.
Cox
,
M. M.
, and
Nelson
,
D. L.
, 2004, Lehninger Principles of Biochemistry,
W. H.
Freeman
, New York.
35.
Heshmat
,
H.
,
Pinkus
,
O.
, and
Godet
,
M.
, 1989, “
On a Common Tribological Mechanism Between Interacting Surfaces
,”
STLE Tribol. Trans.
,
32
, pp.
32
41
.
36.
Heshmat
,
H.
, 2010,
Tribology of Interface Layers
,
CRC
,
New York
.
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