Stick–slip motion and controlled filling speed by the geometric design of soft micro-channels
Journal article, 2018
Hypothesis
Liquid can move by capillary action through interconnected porous materials, as in fabric or paper towels. Today mass transport is controlled by chemical modification. It is, however, possible to direct mass transport by geometrical modifications. It is here proposed that it is possible to tailor capillary flow speed in a model system of micro-channels by the angle, size and position of attached side channels.
Experiments
A flexible, rapid, and cost-effective method is used to produce micro-channels in gels. It involves 3D-printed moulds in which gels are cast. Open channels of micrometre size with several side channels on either one or two sides are produced with tilting angles of 10 – 170°. On a horizontal plane the meniscus of water driven by surface tension is tracked in the main channel.
Findings
The presence of side channels on one side slowed down the speed of the meniscus in the main channel least. Channels having side channels on both sides with tilting angles of up to 30° indicated tremendously slower flow, and the liquid exhibited a stick-slip motion. Broader side channels decreased the speed more than thinner ones, as suggested by the hypothesis. Inertial forces are suggested to be important in branched channel systems studied here.
Liquid can move by capillary action through interconnected porous materials, as in fabric or paper towels. Today mass transport is controlled by chemical modification. It is, however, possible to direct mass transport by geometrical modifications. It is here proposed that it is possible to tailor capillary flow speed in a model system of micro-channels by the angle, size and position of attached side channels.
Experiments
A flexible, rapid, and cost-effective method is used to produce micro-channels in gels. It involves 3D-printed moulds in which gels are cast. Open channels of micrometre size with several side channels on either one or two sides are produced with tilting angles of 10 – 170°. On a horizontal plane the meniscus of water driven by surface tension is tracked in the main channel.
Findings
The presence of side channels on one side slowed down the speed of the meniscus in the main channel least. Channels having side channels on both sides with tilting angles of up to 30° indicated tremendously slower flow, and the liquid exhibited a stick-slip motion. Broader side channels decreased the speed more than thinner ones, as suggested by the hypothesis. Inertial forces are suggested to be important in branched channel systems studied here.
capillary action
Lucas–Washburn equation
Foam structures
pinning meniscus
Author
Johanna Andersson
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Anette Larsson
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Anna Ström
Chalmers, Chemistry and Chemical Engineering, Applied Chemistry
Journal of Colloid and Interface Science
0021-9797 (ISSN) 1095-7103 (eISSN)
Vol. 524 139-147SuMo BIOMATERIALS (Stage 4)
Akzo Nobel - Pulp and Performance Chemicals (1032593), 2017-12-05 -- 2020-12-31.
Mölnlycke healthcare (1000057), 2015-03-01 -- 2017-02-28.
Akzo Nobel - Pulp and Performance Chemicals (1001653), 2015-01-01 -- 2016-12-31.
SCA Hygiene Products AB (1007707), 2015-01-01 -- 2016-12-31.
Stora Enso AB (1018187), 2015-01-01 -- 2016-12-31.
VINNOVA (2015-03150), 2015-03-01 -- 2017-02-28.
Subject Categories
Materials Engineering
Physical Chemistry
Bio Materials
Chemical Engineering
Materials Chemistry
Bioenergy
Biomaterials Science
Areas of Advance
Production
Materials Science
DOI
10.1016/j.jcis.2018.03.070