Adhesion study at the interface of PDMS-elastomer and borosilicate glass-slide

TL;DR

This study investigates how varying the mechanical properties and thickness of PDMS elastomer affects adhesion to borosilicate glass, providing insights for microdevice design and surface interaction control.

Contribution

It demonstrates that increasing the elastic modulus and thickness of PDMS reduces adhesion strength at the PDMS-glass interface, highlighting mechanical property tuning as a method for adhesion control.

Findings

Higher PDMS modulus decreases work of adhesion.

Thicker PDMS samples show increased crack length.

Adhesion can be modulated by mechanical property adjustments.

Abstract

Adhesion control at the interface of two surfaces is crucial in many applications. Examples are the design of micro and nanodevices such as microfuidics devices, biochips, and electronic sensors. Adhesion at the interface of two materials can be controlled by various methods such as chemical treatment on the surface of the materials, modification of the surface texture of materials, and change of the mechanical properties of materials. The main idea of this study is to control the adhesion by changing the mechanical properties (modulus) of polydimethylsiloxane (PDMS) elastomer. We vary the modulus of PDMS elastomer by changing the mixing ratio of silicone elastomer base mixing ratio and its curing agent (Sylgard 184, Dow Corning). Our study also includes the effect of the thickness of the PDMS elastomer sheet on its adhesion behavior. Adhesion measurements at the interface of the borosilicate glass slide and different PDMS elastomer specimens were performed using a wedge test. This method inserts a glass coverslip at the interface to create the wedge. We observe a significant decrease in the work of adhesion and an increase in equilibrium crack length with an increase in elastic-modulus and thickness of the PDMS elastomer samples. We present and discuss the effect of modulus and specimen-thickness on the adhesion behavior of PDMS elastomer against glass slide.