Natural and induced surface roughness determine frictional regimes in hydrogel pairs

Raisa E.D. Rudge, Elke Scholten, Joshua A. Dijksman*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Hydrogels display extremely complex frictional behavior with surprisingly slippery surfaces. We measure the sliding behavior of hydrogels submerged in water using a custom-made tribotool. Samples with an imposed surface roughness give two distinct frictional regimes. Friction coefficients in the first regime change with asperity sizes and Young's moduli. Under increased normal force, a second frictional regime emerges likely due to smoothening of asperities. Friction coefficients in the second regime remain constant across length scales of roughness and appear to be material specific. The hydrogel polymer network also directly influences the surface topography, and with that, the frictional behavior of hydrogels. We highlight the tribological importance of surface roughness at different length scales, which provides potential to engineer functional frictional behavior.

Original languageEnglish
Article number105903
JournalTribology International
Volume141
DOIs
Publication statusPublished - 1 Jan 2020

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Hydrogels
Hydrogel
surface roughness
Surface roughness
coefficient of friction
Friction
Surface topography
Polymers
Elastic moduli
engineers
sliding
Engineers
modulus of elasticity
topography
roughness
Water
polymers
water

Keywords

  • Asperity size
  • Friction
  • Hydrogels
  • Surface roughness

Cite this

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title = "Natural and induced surface roughness determine frictional regimes in hydrogel pairs",
abstract = "Hydrogels display extremely complex frictional behavior with surprisingly slippery surfaces. We measure the sliding behavior of hydrogels submerged in water using a custom-made tribotool. Samples with an imposed surface roughness give two distinct frictional regimes. Friction coefficients in the first regime change with asperity sizes and Young's moduli. Under increased normal force, a second frictional regime emerges likely due to smoothening of asperities. Friction coefficients in the second regime remain constant across length scales of roughness and appear to be material specific. The hydrogel polymer network also directly influences the surface topography, and with that, the frictional behavior of hydrogels. We highlight the tribological importance of surface roughness at different length scales, which provides potential to engineer functional frictional behavior.",
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Natural and induced surface roughness determine frictional regimes in hydrogel pairs. / Rudge, Raisa E.D.; Scholten, Elke; Dijksman, Joshua A.

In: Tribology International, Vol. 141, 105903, 01.01.2020.

Research output: Contribution to journalArticleAcademicpeer-review

TY - JOUR

T1 - Natural and induced surface roughness determine frictional regimes in hydrogel pairs

AU - Rudge, Raisa E.D.

AU - Scholten, Elke

AU - Dijksman, Joshua A.

PY - 2020/1/1

Y1 - 2020/1/1

N2 - Hydrogels display extremely complex frictional behavior with surprisingly slippery surfaces. We measure the sliding behavior of hydrogels submerged in water using a custom-made tribotool. Samples with an imposed surface roughness give two distinct frictional regimes. Friction coefficients in the first regime change with asperity sizes and Young's moduli. Under increased normal force, a second frictional regime emerges likely due to smoothening of asperities. Friction coefficients in the second regime remain constant across length scales of roughness and appear to be material specific. The hydrogel polymer network also directly influences the surface topography, and with that, the frictional behavior of hydrogels. We highlight the tribological importance of surface roughness at different length scales, which provides potential to engineer functional frictional behavior.

AB - Hydrogels display extremely complex frictional behavior with surprisingly slippery surfaces. We measure the sliding behavior of hydrogels submerged in water using a custom-made tribotool. Samples with an imposed surface roughness give two distinct frictional regimes. Friction coefficients in the first regime change with asperity sizes and Young's moduli. Under increased normal force, a second frictional regime emerges likely due to smoothening of asperities. Friction coefficients in the second regime remain constant across length scales of roughness and appear to be material specific. The hydrogel polymer network also directly influences the surface topography, and with that, the frictional behavior of hydrogels. We highlight the tribological importance of surface roughness at different length scales, which provides potential to engineer functional frictional behavior.

KW - Asperity size

KW - Friction

KW - Hydrogels

KW - Surface roughness

U2 - 10.1016/j.triboint.2019.105903

DO - 10.1016/j.triboint.2019.105903

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VL - 141

JO - Tribology International

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