Continuous flowing micro-reactor for aqueous reaction at temperature higher than 100 °C

Area of Science:

• Chemical Engineering
• Analytical Chemistry
• Microfluidics

Background:

• High-temperature aqueous reactions (>100°C) typically require autoclaves to generate high pressure.
• Autoclaves are bulky and limit continuous processing for reactions in biological and chemical fields.
• An alternative method for achieving high-temperature aqueous reactions is needed for microfluidic systems.

Purpose of the Study:

• To present a continuous flowing microfluidic solution for aqueous reactions above 100°C.
• To demonstrate a novel pressure-regulating microchannel for high-temperature microfluidic applications.
• To enable high-pressure/high-temperature environments within a microfluidic chip for continuous processing.

Main Methods:

• Developed a microfluidic chip using silicon-based microfabrication.
• Integrated micro heaters and temperature sensors onto the chip.
• Designed a pressure-regulating microchannel based on hydrodynamic principles for continuous flow.

Main Results:

• Successfully generated a high-pressure (990 kPa) and high-temperature (145°C) environment in the microfluidic reactor.
• Demonstrated the thermal digestion of aqueous total phosphorus samples under these conditions.
• Achieved this using a low flow rate of 20 nl/s, showcasing precise control.

Conclusions:

• The developed continuous flowing microfluidic system offers an alternative to autoclaves for high-temperature aqueous reactions.
• The integrated pressure-regulating microchannel is effective for creating controlled high-pressure/high-temperature conditions.
• This technology has potential applications in micro total analysis systems and other microfluidic-based chemical processes.