Touch-Enabled Reversible Microfluidic Ultradense Chips for Convenient, High-Throughput Electrochemical Assays.
Pedro H N da Silva1,2, Paula C R Corsato1,2, Christian O Silva1,3
1Brazilian Nanotechnology National Laboratory,Brazilian Center for Research in Energy and Materials,Campinas, São Paulo 13083-970, Brazil.
ACS Applied Materials & Interfaces
|July 21, 2025
Summary
This study introduces a simple, reversible dry bonding method for polydimethylsiloxane (PDMS) microfluidic channels on SU-8 chips, enabling high-throughput electrochemical assays with enhanced durability and reusability for diverse applications.
Area of Science:
- Microfluidics
- Materials Science
- Electrochemistry
Background:
- Traditional methods for bonding polydimethylsiloxane (PDMS) microfluidic channels often lack simplicity, reversibility, or sufficient adhesion for high-throughput applications.
- Plasma-mediated bonding, while common, can be irreversible and may not always guarantee leak-free seals.
Purpose of the Study:
- To develop a novel, reversible dry bonding technique for integrating PDMS microfluidic channels with SU-8 coated chips.
- To enable low-cost, scalable, and high-throughput electrochemical assays through improved microfluidic device fabrication.
Main Methods:
- A manual dry bonding approach was developed by positioning PDMS outlets at the bottom of the channels, requiring only manual attachment to a flat surface.
- The developed bonding method was tested for adhesion strength, pressure tolerance, and compared against plasma-mediated approaches.
- Proof-of-concept applications included microelectrode fabrication, cancer cell monitoring, and phosphate determination in biological fluids.
Main Results:
- The reversible dry bonding achieved high adhesion strength (≥5.1 MPa) and was leak-free, surpassing limitations of plasma-mediated methods.
- The technique demonstrated simplicity, throughput, reversibility, long-term shelf life, and reusability.
- Successful high-throughput electrochemical assays were performed, analyzing 45 samples in approximately 135 seconds.
Conclusions:
- The developed reversible dry bonding method offers a robust, versatile, and cost-effective solution for fabricating microfluidic devices for high-throughput electrochemical analyses.
- This generalizable technique is compatible with various materials and holds significant potential for diverse microfluidic applications, including sensor regeneration and in-channel material manipulation.
