Automated 3D Immunoassay Platform Using MUX Valve powered by AMF RVM

Automating fluid handling in microfluidic systems often requires reliable components that can manage complex reagent routing without compromising on precision or repeatability. In a recent application note, Elveflow presents a fully integrated microfluidic immunoassay platform built around a three-dimensional PDMS flow cell and chronoamperometric detection. At the core of the reagent distribution system is their MUX Recirculation Valve, which incorporates AMF’s RVM microfluidic rotary valve to switch between multiple fluid paths. Combined with Elveflow’s software interface, the MUX allows for automated control of reagent injection steps, supporting compact and reproducible assay workflows in a modular format.

Challenge

Automating immunoassays in a microfluidic format presents a range of technical challenges: the need for precise fluid handling at the microliter scale, the integration of multiple reagents without cross-contamination, and the ability to run continuous, high-sensitivity measurements with minimal manual intervention. Traditional setups often struggle with system complexity, inconsistent flow control, and bubble formation, issues that can severely impact reproducibility and assay performance.

In this specific application, Elveflow aimed to transition a conventional HRP/TMB-based immunoassay into a fully integrated, three-dimensional microfluidic system capable of real-time electrochemical detection. This required a reliable way to sequentially inject various fluids, such as buffers, enzyme complexes, and reaction substrates, into a 3D-printed PDMS flow cell, all while maintaining clean switching, minimal dead volume, and full automation.

Setup (made by Elveflow)

Meeting this challenge demanded a fluid routing solution that could handle high-frequency switching, integrate easily into a pressure-driven flow system, and ensure reagent integrity. That’s exactly where our technology comes in.

Our solution

To meet the demands of precise, multi-reagent injection and full automation, Elveflow integrated our RVM microfluidic rotary valve into their system as the core of their MUX Recirculation Valve. This 6-to-1 recirculation setup enables seamless routing of multiple fluids, buffers, substrates, and wash solutions, into the microfluidic flow cell without manual intervention or complex tubing arrangements.

Thanks to the RVM’s ultra-low internal volume, clean switching performance, and dead-volume-free architecture, Elveflow was able to ensure reliable, contamination-free fluid handling in a compact format. Controlled through Elveflow’s software suite, the MUX operates in full synchronization with pressure controllers, flow sensors, and bypass valves, delivering a responsive and programmable fluidic system tailored for continuous assay operation.

By combining the robustness of AMF’s RVM with Elveflow’s automation platform, the result is a powerful tool for immunoassay integration and biosensor prototyping.

And this is how in practice the MUX operates: one reservoir is pressurized to drive liquid through the perfusion chamber toward the second, non-pressurized reservoir. The valve alternates between Injection positions 1 and 2, allowing the direction of transfer between reservoirs to switch while keeping the flow through the chip strictly unidirectional.

Principle of the MUX recirculation setup (made by Elveflow)

Benefits

By leveraging the performance of the RVM inside the MUX Recirculation Valve, Elveflow achieved a number of critical advantages that directly addressed the limitations of conventional microfluidic immunoassay setups:

• Automated multi-reagent handling: The 6-to-1 configuration enabled by the RVM allows for seamless and fully automated switching between reagents, reducing manual intervention and setup complexity.
• Minimal dead volume & carryover: The internal geometry of the RVM minimizes dead volume and prevents reagent cross-contamination, ensuring reliable assay performance and clean transitions between fluidic steps.
• Compact & scalable integration: The compact footprint of the RVM made it easy to embed within Elveflow’s modular platform, supporting complex assay workflows without occupying additional space or requiring custom infrastructure.
• Software-driven control: Integrated into Elveflow’s software environment, the valve system could be precisely programmed to coordinate with other components like pressure regulators and flow sensors, enabling true plug-and-play automation.
• Reliable, reproducible flow: Combined with a 3D microfluidic chip and pressure-based actuation, the MUX + RVM system delivered stable, bubble-free flow essential for accurate chronoamperometric measurements.

Results

The integrated system enabled by Elveflow delivered impressive performance across all stages of the immunoassay workflow. The RVM-powered MUX Recirculation Valve allowed for precise, repeatable injections of up to twelve different reagents into the custom 3D microfluidic flow cell, facilitating a fully automated and reproducible assay cycle.

Thanks to optimized fluid switching and stable pressure-driven flow, the platform achieved high signal intensity with fast response times, essential for chronoamperometric detection. The electrochemical readout of the oxidized TMB showed clear, concentration-dependent signals, enabling sensitive quantification of diclofenac via a competitive assay format.

MCF7 cells cultured under continuous medium recirculation (made by Elveflow)

The robust automation architecture, supported by the RVM’s mechanical precision, also enabled low reagent consumption (only 100–300 µL per assay), minimal system downtime, and reliable assay repeatability over multiple cycles. Ultimately, Elveflow succeeded in transforming a lab-scale immunoassay into a miniaturized, continuous, and scalable microfluidic biosensor platform.

Applications

The automated microfluidic system demonstrated in this application note highlights the versatility of the MUX Recirculation Valve powered by AMF’s RVM in advanced bioanalytical workflows. While the showcased use case focused on a competitive immunoassay for diclofenac detection, the platform’s modular architecture and precise fluid control make it suitable for a broad range of applications, including:

• Electrochemical biosensors: Enabling real-time, label-free detection of various biomarkers in clinical or environmental settings.
• Enzyme kinetics studies: Allowing for precise, repeatable mixing of enzymes and substrates under tightly controlled conditions.
• Pharmaceutical screening: Supporting the miniaturization and automation of compound testing protocols.
• Food and water quality testing: Facilitating sensitive, on-site detection of contaminants or residues.
• Point-of-care diagnostic development: Providing a scalable, programmable fluidic backbone for emerging diagnostic technologies.

With the RVM at its core, the MUX-enabled system offers a reliable solution for any application requiring multiplexed reagent handling, compact integration, and high-frequency switching in microfluidics.

Conclusion

Elveflow’s application of the MUX Recirculation Valve, powered by AMF’s RVM microfluidic rotary valve, demonstrates how advanced fluidic control can unlock new possibilities in biosensor development and assay automation. By integrating precise reagent switching, low dead volume, and software-driven programmability into a compact microfluidic setup, they successfully transitioned a conventional immunoassay into a fully automated, miniaturized, and scalable system.

This collaboration highlights the value of combining robust microfluidic components with flexible system architecture. Whether for research, diagnostics, or industrial applications, the RVM continues to enable high-performance solutions where reliable and intelligent fluid handling is key.

About Elveflow

Elveflow is a leading provider of laboratory microfluidic instruments, headquartered in Paris, France. Specializing in high-precision flow control, sensors, and integrated platforms, the company supports researchers in life sciences, diagnostics, and materials science. With a focus on flexibility and ease of use, Elveflow’s systems are designed to accelerate experiments, improve reproducibility, and simplify the path from prototyping to advanced applications.