Mechanically Tunable Slippery Behavior on Soft Poly(dimethylsiloxane) (PDMS) Based Anisotropic Wrinkles Infused with Lubricating Fluid

TL;DR

This paper presents a method to create mechanically tunable slippery surfaces using anisotropic elastic wrinkles infused with lubricating fluid, enabling reversible control of slip behavior depending on mechanical strain and wrinkle orientation.

Contribution

The study introduces a novel approach to fabricate elastomeric slippery surfaces with tunable anisotropic properties via mechanically controlled wrinkle topography.

Findings

Tunable slippery behavior achieved through mechanical stretching of wrinkles.

Lubricant infusion results in excellent slip on stretched surfaces and poor slip on relaxed surfaces.

Anisotropic slip behavior depends on wrinkle orientation relative to the test liquid drops.

Abstract

We demonstrate a novel technique to fabricate mechanically tunable slippery surfaces using one dimensional (anisotropic) elastic wrinkles. Such wrinkles show tunable topography (amplitude) on the application of mechanical strain. Following Nepenthes pitcher plants, lubricating fluid infused solid surfaces show excellent slippery behavior for test liquid drops. Therefore combining the above two i.e. infusing suitable lubricating fluid on elastic wrinkles would enable us to fabricate mechanically tunable slippery surfaces. Completely stretched (flat) wrinkles have uniform coating of lubricating fluid whereas completely relaxed (full amplitude) wrinkles have most of the lubricating oil in the wrinkle grooves. Therefore water drops on completely stretched surface show excellent slippery behavior whereas on completely relaxed surface they show very poor slippery behavior. Therefore continuous variation of wrinkle stretching provide reversibly tunable slippery behavior on such system. Since the winkles are one dimensional, they show anisotropic tunability of slippery behavior depending upon whether test liquid drops slip parallel or perpendicular to the wrinkles.