Surface Texture Effect on Friction of a Microtextured Poly(dimethylsiloxane) (PDMS)

Abstract

The effect of surface textures on the friction of a poly(dimethylsiloxane) (PDMS) elastomer has been investigated at both macro and microscales using a nanoindentation-scratching system. Friction tests were conducted by a stainless-steel bearing ball with a diameter of 1.6 mm (macroscale tests) and a Rockwell diamond tip with a radius of curvature of 25 lm (microscale tests) under normal loads of 5, 10, and 25 mN and with a sliding speed of 1 lm/s. Coefficient of friction (COF) on the pillartextured surface was found to be much lower than that on the smooth surface of the same material, and it was reduced by about 59% at the macroscale tests and 38% at the microscale tests. The reduction of COF can be attributed to the reduced contact areas. The use of the JKR model revealed that the adhesion force has less effect on contacts under higher normal loads. COFs in different sliding directions on the groove-textured surfaces were compared, and a friction anisotropic behavior was identified and analyzed.

Direct Laser Interference Patterning: Tailoring of Contact Area for Frictional and Antibacterial Properties

“…Additionally, Rosenkranz et al continued this work also for larger sliding cycles (up to 20,000 cycles) in order to study degradation effects of the patterned surfaces in more detail. They could show that the laser patterns still exist even after longer sliding times and that there is a general tendency for smaller COF's in the case of perpendicular compared to parallel sliding to the line patterns due to a reduced contact area, which is in good agreement with He et al [27,28]. Recently, Yu et al published research work on pattern orientation effects for nano-and micro grooved surfaces.…”

“…Furthermore, all samples roughly start from the same initial COF. From the literature, it is well known that the frictional response for para-and perp-alignments can be quite different [28,47,48]. Recently, Yu et al were able to demonstrate that the contact area, the stiction length, the energy barrier and the contact stiffness are the most influencing factors for the frictional behavior with respect to these two extreme cases [29].…”

Polymer Jet Printing of SU-8 Micro-Dot Patterns on Si Surface: Optimization of Tribological Properties

“…Recently, He et al [5] have studied poly(dimethylsiloxane) (PDMS) elastomer with surface textures that can significantly reduce coefficient of friction at the macroscale level but not at the microscale. The macroscale test used a steel ball of 1.6-mm diameter whereas the microscale test used a diamond tip of radius 25 lm against pillars and grooves on the patterned surface.…”

Development of highly durable and low friction micro-structured PDMS coating based on bio-inspired surface design

“…The thickness of the PDMS was set to the actual thickness of the specimens. Young's modulus and Poisson's ratio of PDMS used were 750 kPa and 0.48, respectively [6]. The friction coefficient values that were obtained from the experiments were used in the analysis.…”

“…Though high hardness is effective to battle abrasive interaction, it is not the primary parameter related to adhesion, which is another important mechanism of wear [4,5]. Since, adhesion is strongly related with the real contact area [6], an effective method to reduce adhesion is to minimize the contact area between the two surfaces. For this purpose, surface textures and dimple patterns have been widely employed to reduce the contact area and stiction of precision devices [7].…”