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Title: Meso-scale dislocations and friction of shape-complementary soft interfaces
The interface between two surfaces patterned with complementary shapes such as arrays of ridge–channel structures or pillars accommodates relative misorientation and lattice mismatch by spontaneous production of dislocation arrays. Here, we show that the relative sliding of such an interface is accomplished by dislocation glide on the interfacial plane. An exception is the singular case where the lattices are perfectly matched across the sample dimension, in which case sliding is accompanied by motion of edge-nucleated defects. These are meso-scale analogues of molecular sliding friction mechanisms between crystalline interfaces. The dislocations, in addition to the long-range elastic energy associated with their Burgers vectors, also cause significant out-of-plane dilation, which props open the interface locally. For this reason, the sliding friction is strongly pressure dependent; it also depends on the relative orientation of the patterns. Sliding friction can be strongly enhanced compared with a control, showing that shape-complementary interfaces can be engineered for strongly enhanced pressure- and orientation-dependent frictional properties in soft solids.  more » « less
Award ID(s):
1854572
NSF-PAR ID:
10283326
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Journal of The Royal Society Interface
Volume:
18
Issue:
175
ISSN:
1742-5662
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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