Abstract Results - isbe-online.orgthe toe pad of tree frogs, in which hexagonal arrays of ... The...
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PS nanopillar array
(Vinyl-group
modified)
Casting of PDMS
precursor
PDMS precursor
High pressure
& RT
Cool down in
liquid N2
Ni mold
Remove supporting
layer of PS
nanopillars
Casting of PDMS
precursor
Curing &
demolding
The composite structure of keratinized epithelium on
the toe pad of tree frogs, in which hexagonal arrays of
soft epithelial cells are crossed by densely packed and
oriented hard keratin nanofibrils, endows them with a
good adhesion capability. Inspired by the composite
design, composite micropatterns composed of a soft
matrix and perpendicularly oriented rigid nanopillars
with tunable surface chemistry have been fabricated.
Studies of adhesion and friction of these synthetic
materials reveal a benefit of the hierarchical and
anisotropic design for both adhesion and friction.
Materials & Methods
Abstract
1. Hybrid Surface Patterns Mimicking the Design of the
Adhesive Toe Pad of Tree Frog. ACS Nano 2017; DOI:
10.1021/acsnano.7b04994
2. Torrent Frog-Inspired Adhesives: Attachment to Flooded
Surfaces. Adv. Funct. Mater. 2015, 25, 1499–1505
The composite micropillar inspired by the toe pad of tree frog
shows enhanced adhesion and friction. The proposed method
is generic and flexible, and can be extended to other surface
designs and material combinations.
References
Results
Conclusion & Perspective
Comp/Comp+: composite pillar array without/with the
modification of vinyl groups
(a) (b)
2017 International Bionic Innovation Competition
The stress distribution of PDMS (a), Comp (b) and Comp+
(c) micropillars. Comp+ micropillars can reduce the value
of stress maximum and shift the stress maximum toward the
central region.
(a) (b) (c)
𝐹𝑠ℎ𝑒𝑎𝑟 =𝑛𝐺𝐴𝐷𝑠ℎ
(a) Dependence of adhesion
force (Fad) on loading
force (FL) measured on
PDMS, Comp and Comp+
micropillar arrays.
(d)
(e)(e) Ds measured on Comp+ and PDMS
micropillar arrays. The larger shear
modulus (G) and transverse
distance (Ds) of the composite pillar
along the shear direction endow the
Comp+ micropillars with enhanced
shear force (Fshear).
h: pillar height; A: contact area
(b) Dependence of friction
force (Ff ) on FL on
Comp+, Comp and
PDMS micropillar
arrays.
(d) Fraction of the detachment
curve after the pull-off
point on Comp+ and
PDMS micropillar arrays.
①Motorized xyz-stage;
② Vertical and ③ lateral piezo
translation stage;
④ Lateral and ⑧ vertical load
sensor;
⑤ Sample holder;
⑥ Sample;
⑦ Ruby sphere probe;
⑨ Video microscope.
Adhesion and friction force tester