Actively Driven Light-Addressable Sensor/Actuator System for Automated pH Control for the Integration in...

Area of Science:

• Microfluidics
• Chemical Sensing
• Semiconductor Devices

Background:

• Microfluidic systems face challenges integrating internal sensors and actuators.
• External control of microfluidic environments is crucial for biological and chemical applications.

Purpose of the Study:

• To demonstrate a microfluidic system with externally controlled, light-addressable sensors and actuators.
• To enable precise spatial and temporal control of pH gradients within microchannels.

Main Methods:

• Integration of a light-addressable potentiometric sensor (Al/Si/SiO2/Si3N4) for pH measurement.
• Incorporation of light-addressable electrodes (glass/SnO2:F/TiO2) for photoelectrocatalytic pH control.
• Simultaneous operation of sensor and electrode within a microfluidic setup under static and dynamic flow.

Main Results:

• Achieved pH changes up to ΔpH 3.52 under dynamic flow conditions.
• Demonstrated tailored pH gradients perpendicular to flow (ΔpH 1.42).
• Showcased stepwise pH increase via synchronous light-addressable electrode illumination.

Conclusions:

• Externally light-controlled semiconductor devices offer a viable solution for advanced microfluidic control.
• The developed system allows for precise generation and monitoring of pH gradients in microfluidic channels.
• This technology has potential applications in lab-on-a-chip devices and chemical analysis.