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Capacitive Sensing for Monitoring of Microfluidic Protocols Using Nanoliter Dispensing and Acoustic Mixing
Yaqi Zhang1, Muhsincan Sesen1,2, Alex de Marco3,4
1Department of Mechanical and Aerospace Engineering, Monash University, Clayton, Victoria, Australia.
Analytical Chemistry
|July 7, 2020
Summary
This study introduces a microfluidic system with on-chip protocol development using a valve-regulated cavity and surface acoustic wave mixing. Capacitive sensing enables accurate fluid dispensing and monitoring, facilitating multiplexed bio/chemical reactions without optical assessment.
Area of Science:
- Microfluidics
- Biochemical Engineering
- Sensing Technologies
Background:
- Developing bio/chemical reaction protocols often requires complex, multi-step dispensing and mixing.
- Existing microfluidic systems typically necessitate pre-defined chip designs for specific fluid volumes, limiting on-chip protocol flexibility.
Purpose of the Study:
- To present a novel microfluidic approach enabling on-chip development and refinement of bio/chemical reaction protocols.
- To demonstrate precise fluid handling and reaction monitoring capabilities within a microfluidic device.
Main Methods:
- Utilizing a microfluidic valve to control fluid ingress into an empty cavity for flexible volume dispensing.
- Employing surface acoustic wave (SAW) excitation for efficient on-chip fluid mixing via steady-state streaming.
- Implementing capacitive sensing for accurate fluid level detection and monitoring of reaction parameters.
Main Results:
- Achieved nanoliter dispensing accuracy with capacitive sensing, even with multiple fluid types.
- Demonstrated the ability of capacitive readout to assess mixing quality and monitor temperature fluctuations.
- Validated the system's capability for optical-free protocol execution and multiplexed reaction capabilities.
Conclusions:
- The developed microfluidic system offers a flexible platform for on-chip protocol development and optimization.
- Capacitive sensing provides a versatile tool for precise fluid control, reaction monitoring, and quality assessment.
- This technology enables efficient, multiplexed biochemical assays, advancing microfluidic applications.
