Issue 24, 2025, Issue in Progress

Surface roughness in microfluidic device fabrication: limitations of conventional methods and a novel solution for multi-material bonding

Abstract

Microfluidic devices, especially those utilizing polydimethylsiloxane (PDMS) structures, require reliable bonding methods to achieve durable, leak-proof seals. Current bonding techniques, including O2 plasma treatment, suffer from limitations related to material compatibility and surface roughness sensitivity, which compromise device stability and scalability in complex designs. In this study, we investigate the impact of surface roughness, wax contamination, and the presence of conductive materials on bonding strength in PDMS-based microfluidics. Additionally, we propose a novel bonding method using a flowable, one-component silicone rubber that forms robust seals without plasma treatment or silanization, effectively overcoming the challenges posed by increased surface roughness and material heterogeneity. The bonding method demonstrated significantly enhanced bond strengths across various substrate combinations (PDMS, copper, and FR4), with notable resilience under high pressure. This approach advances microfluidic fabrication by offering a scalable, versatile solution for multi-material bonding applicable in digital microfluidics and beyond.

Graphical abstract: Surface roughness in microfluidic device fabrication: limitations of conventional methods and a novel solution for multi-material bonding

Supplementary files

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Article information

Article type
Paper
Submitted
17 Apr 2025
Accepted
29 May 2025
First published
10 Jun 2025
This article is Open Access
Creative Commons BY license

RSC Adv., 2025,15, 19254-19262

Surface roughness in microfluidic device fabrication: limitations of conventional methods and a novel solution for multi-material bonding

C. Lehmann, D. Singh, M. Gastearena and L. M. Comella, RSC Adv., 2025, 15, 19254 DOI: 10.1039/D5RA02701B

This article is licensed under a Creative Commons Attribution 3.0 Unported Licence. You can use material from this article in other publications without requesting further permissions from the RSC, provided that the correct acknowledgement is given.

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