Dislocations at Patterned Soft Material Interfaces Control Adhesion and Friction

Shape-complementary patterning of two soft material surfaces creates an interface with highly selective adhesion and tunable friction.  The interface spontaneously creates arrays of dislocations with mixed edge and screw character.

Adhesion

We have studied how one can endow a surface with selectivity of adhesion. One way is to use shape complementarity, either wavy surfaces with matched profiles or pillar-channel surfaces. Another way is to use charge complementarity.

Demonstration that shape-complementary ridge-channel structures accomodate misorientation by forming interfacial screw dislocations.

Singh, Arun K., Ying Bai, Nichole Nadermann, Anand Jagota, and Chung-Yuen Hui. “Adhesion of microchannel-based complementary surfaces.” Langmuir 28, no. 9 (2012): 4213-4222.

Study of dislocation structure and energetics in relation to adhesion.

Jin, Congrui, Anand Jagota, and Chung‐Yuen Hui. “Structure and Energetics of Dislocations at Micro‐Structured Complementary Interfaces Govern Adhesion.” Advanced Functional Materials 23, no. 27 (2013): 3453-3462.

Geometry of dislocation density and orientation for misaligned structured surfaces with lattice parameter mismatch.

 

Friction

Dislocations at interfaces can also be used to create highly tunable friction.  This is ongoing work.