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Study on Functionality and Surface Modification of a Stair-Step Liquid-Triggered Valve for On-Chip Flow Control
Xi Chen1, Sihui Chen1, Yi Zhang2,3
1Laboratory of Biomedical Microsystems and Nano Devices, Bionic Sensing and Intelligence Center, Institute of Biomedical and Health Engineering, Shenzhen Institutes of Advanced Technology, Chinese Academy of Science, Shenzhen 518055, China.
Micromachines
|July 26, 2020
Summary
This study introduces a novel stair-step liquid-triggered valve for capillary microfluidics. The research details valve functionality, surface modifications, and fluidic behavior, enhancing autonomous micro-system design.
Area of Science:
- Microfluidics
- Autonomous micro-systems
- Capillary-driven systems
Background:
- Capillary microfluidics offers precise fluid control in autonomous systems.
- Micro-valves are crucial for sequential operations in microfluidic devices.
- Existing micro-valves often require external triggers, limiting autonomy.
Purpose of the Study:
- To present a novel stair-step liquid-triggered valve for capillary microfluidic circuits.
- To investigate the valve's functionality, geometric, and surface modification dependencies.
- To evaluate the impact of surface treatments on valve reliability and shelf life.
Main Methods:
- Fabrication of stair-step micro-valves.
- Surface modification using polyethylene glycol (PEG) and (3-Aminopropyl) triethoxysilane (APTES).
- Experimental evaluation of surface contact angles and fluidic behavior.
Main Results:
- Demonstrated functionality of the stair-step liquid-triggered valve.
- Quantified the effect of PEG and APTES coatings on contact angles and valve reliability.
- Investigated contact angle variations over time to determine device shelf life.
- Characterized overall fluidic behavior within the capillary valves.
Conclusions:
- The stair-step liquid-triggered valve offers a reliable, autonomous fluidic control mechanism.
- Surface modification strategies (PEG, APTES) are critical for optimizing valve performance and longevity.
- Understanding fluidic behavior is essential for efficient capillaric circuit design.
