Adhesion study at the interface of a PDMS-elastomer and borosilicate glass-slide: effect of modulus and thickness of the elastomer

Susheel Kumar ¹, Chiranjit Majhi ², Krishnacharya Khare ²

⁰Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, India. manjesh@iitk.ac.in.

Soft Matter +

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March 6, 2025

View abstract on PubMed

Summary

Controlling adhesion is key for microdevices. This study shows that increasing the elastic modulus and thickness of polydimethylsiloxane (PDMS) elastomer reduces adhesion to glass, offering a new control method.

Area Of Science

Materials Science
Surface Science
Mechanical Engineering

Background

Adhesion control is critical for micro/nanoscale devices like microfluidics and sensors.
Current methods include surface treatments, texture modification, and altering mechanical properties.

Purpose Of The Study

To investigate controlling adhesion by modifying the mechanical properties (elastic modulus) of polydimethylsiloxane (PDMS) elastomer.
To examine the influence of PDMS elastomer thickness on adhesion behavior.

Main Methods

Varying the elastic modulus of PDMS by adjusting the mixing ratio of its base and curing agent (Sylgard 184).
Assessing adhesion using a wedge test at the interface between PDMS specimens and borosilicate glass slides.
Measuring the work of adhesion and equilibrium crack length.

Main Results

Increased elastic modulus of PDMS led to a significant decrease in the work of adhesion.
Increased PDMS thickness also resulted in reduced adhesion to the glass substrate.
Equilibrium crack length increased with higher elastic modulus and thickness.

Conclusions

The elastic modulus and thickness of PDMS elastomer are effective parameters for controlling adhesion at the glass interface.
Findings provide insights for designing micro/nanodevices with tunable interfacial adhesion.