On-chip pressure sensor using single-layer concentric chambers.

Area of Science:

• Microfluidics
• Sensor Technology
• Biomedical Engineering

Background:

• Accurate local pressure sensing is crucial for microfluidic device operation and analysis.
• Existing methods often require complex setups, additional hardware, or electrical components.
• On-chip pressure sensing offers a streamlined approach for real-time monitoring.

Purpose of the Study:

• To develop and validate a vision-based, on-chip sensor for local pressure measurement in microfluidic systems.
• To demonstrate a simple, low-cost fabrication method for integrated pressure sensing.
• To evaluate the sensor's performance in static and dynamic conditions.

Main Methods:

• A single-layer microfluidic design incorporating a polydimethylsiloxane (PDMS) deformation mechanism.
• Pressure-induced deformation in a dedicated chamber transmitted to a concentric sensing chamber.
• Color intensity changes in a pre-filled colored fluid within the sensing chamber observed via microscopy.
• Experimental validation using regulated static and dynamic input pressures.

Main Results:

• A high correlation (0.97) was achieved for static pressure responses.
• Dynamic pressure responses were successfully detected up to 16 Hz.
• The sensor provides direct visual pressure readings without external hardware or power.
• The single-layer design ensures simple, consistent, and low-cost fabrication.

Conclusions:

• The proposed vision-based sensor offers an effective and direct method for local pressure sensing in microfluidics.
• Its simple design and fabrication facilitate easy integration into existing microfluidic systems.
• This technology presents a cost-effective and accessible solution for microfluidic pressure monitoring.