Micro Coriolis Mass Flow Sensor with Large Channel Diameter Realized by HNA Wet Etching

Area of Science:

• Microfluidics
• Sensor Technology
• Chemical Engineering

Background:

• Standard Surface Channel Technology (SCT) Coriolis sensors have limited flow ranges.
• Microfluidic channel design significantly impacts sensor performance characteristics like flow range and pressure drop.

Purpose of the Study:

• To develop and evaluate a Coriolis mass flow and density sensor with an expanded flow range.
• To investigate the impact of selective wet etching on microfluidic channel geometry and sensor performance.

Main Methods:

• Fabrication of suspended microfluidic channels using selective wet etching.
• Design of channels with a semi-elliptical cross-section (200 μm wide, 70 μm deep).
• Testing sensor performance with water, isopropyl alcohol (IPA), and nitrogen (N2) for mass flow and density.

Main Results:

• Achieved a significantly higher flow range of up to 50 g/h for water, a substantial increase from standard SCT sensors (1.2 g/h).
• Maintained a low pressure drop of 1 bar at the maximum flow rate.
• Demonstrated effective mass flow and density sensing capabilities for various fluids.

Conclusions:

• Selective wet etching enables the creation of microfluidic channels with larger cross-sectional areas, leading to enhanced Coriolis sensor performance.
• The developed sensor offers a superior flow range, making it suitable for a wider array of microfluidic applications.
• The sensor's performance is validated across different fluid types, indicating its versatility.