Liquid adhesion test bench with reclining ramp

Abstract

Developed in partnership with SILSEF and AII Companies R&D teams, the described test bench offers a solution for dynamic liquid adhesion measurements on a wide range of materials. SILSEF develops and produce functional micro and nano-patterns on the industrial scale on a wide range of materials (glass, metal, polymers, semiconductors, thin films, …) in order to add value on surfaces by the modification of their natural properties (for example hydrophilic or hydrophobic properties). To testify the performances of its process, specifically developed for each customer, a tool giving additional measurable and reproducible evidences with a dynamic drop angle measurement was mandatory. AII brought its skills to develop a test bench composed of a motorized and instrumented reclining ramp with twelve optical sensor channels and a dedicated software to adjust test settings and collect results.

Full text

Conclusion and Perspectives
Bench description
Experiments & Results
Liquid adhesion test bench
with reclining ramp
Carole LAVAULT*,2, Valentin GATE*,1 , Sylvain FOURNIER2, Yves LAVAULT2, Lionel CHARPENTIE 3, Daniel TUROVER1,
The ALPINTM bench was developed to characterize functional anti-adhesion on micro or nano-patterned surfaces. It provides
complementary information to standard contact angle measurement.
Transitional phases in morphological evolution of drops before roll-off can be identified. This bench enables dynamic adhesion
measurements of various liquids on a wide range of materials, for research and industrial applications, including biofilm
formation detection with the ability to evaluate residual liquid during and after drop roll-off.
LEDs are used to measure reflectivity variations on the surface to be analyzed: the liquid deposited modifies the reflectivity during the
tilting of the ramp. The light intensity is collected on each channel and processed into curves representing reflected light intensity as a
function of the tilt (0.5° angular resolution).
1 SILSEF, Archamps, France. 2 AII SAS, Cran-Gevrier, France. 3POLARISE, Chambéry, France* valentin.gate@silsef.com; carole.lavault@aii-industrie.com
AII has been developing for years motor-controlled systems coupled
with high precision instrumentation dedicated to specific R&D needs of
researchers and engineers.
The ALPINTM bench is now available for a wide range of research and
industrial applications with various options on demand.
www.aii-industrie.com
Tel: +33450677716 email: contact@aii-industrie.com
Calibrated drop deposition Ramp tilts up to 90° Critical tilt angle detection
Wettability was tested on patterned Polystyrene using 50mL drops of salted water. Measurements were executed in characterization
mode to extract the reflected intensity vs tilt angle.
•A sudden decrease of light intensity is observed at the critical tilt angle, above which the drop rolls off
•The results show an increase in the reflectivity before the drop rolls off
•Each type of pattern exhibits a specific behavior associated to the evolution of reflected intensity during the tilting
•Each curve on graphs A, B and C represents the measurements of a single channel
•Patterns A, B and C exhibit a roll-off angle of 54°, 46°an 17° respectively. Pattern C corresponds to good anti-adhesion properties and
no liquid remains on the surface.
•Assessment of transitional phases in morphological evolution of drops before roll off: the drop geometry varies during motion and
refracts light differently. Zone 1: the drop barely moves. Zone 2: the drop focuses the light. Zone 3: the drop rolls off. Increased
reflectivity in zone 4 reveals liquid still on the patterned surface. Zone 5 corresponds to the surface after the roll-off.
Main features
•12 channels in parallel
•Motorized motion with variable speed
•Tilt angle 0-90°
•Characterization mode for R&D or
Qualification mode for offline control
•Compact portable system
•Joint development by SILSEF and AII of a robust, user
friendly, and versatile tool to characterize anti-adhesion
behavior
•Complementary information to contact angle
•Revelation of residual liquid layer
Further developments:
•Complete understanding of drop behavior
•Evolution to 2.5D surfaces
•Custom development for specific user needs (video
camera, gutter, controlled environment…)
SILSEF develops functional micro and nano-patterns for
wettability, light management, anti-fogging, anti-icing, cell cultures, on
large areas. Industrial customers and academic partners use a wide
range of materials (glass, metal, polymers, semiconductors, thin
films, solgel).
www.silsef.com
Tel: +33450825707 email: contact@silsef.com
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7000
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7
13
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26
33
39
46
52
59
65
72
78
85
Reflected intensity
Tilt angle (°)
~54 °
A
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10
20
30
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70
80
90
Tilt angle (°)
~17°
C
0
5
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32
36
41
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54
59
63
68
72
77
81
86
90
Tilt angle (°)
~46°
B
Zone 4
Zone 1
Zone 2
Zone 5
Zone 3