Ultrafast microfluidic mixer and freeze-quenching device

Area of Science:

• Chemical Kinetics
• Biochemistry
• Microfluidics
• Spectroscopy

Background:

• Freeze-quenching is vital for studying fast reactions but limited by conventional mixer and freezer speeds.
• Existing methods struggle to capture transient intermediates due to slow mixing and freezing times.
• There is a need for faster techniques to probe rapid chemical and biochemical processes.

Purpose of the Study:

• To develop and validate a novel microfluidic mixer coupled with a freeze-quenching device.
• To overcome the temporal limitations of conventional freeze-quenching techniques.
• To enable the study of fast reactions down to microsecond timescales.

Main Methods:

• Designed a microfluidic silicon mixer with staggered vertical pillars to enhance turbulent mixing.
• Integrated a novel freeze-quenching device with rotating copper wheels at 77 K.
• Utilized a high-velocity jet (20 m/s) for rapid mixing and instantaneous freezing.

Main Results:

• Achieved complete mixing within 20 microseconds in the microfluidic mixer.
• Enabled reaction observation at the earliest point of 50 microseconds.
• Demonstrated a speed improvement of approximately two orders of magnitude over commercial instruments.

Conclusions:

• The developed microfluidic freeze-quenching system significantly accelerates the study of fast reactions.
• The system allows for the trapping and analysis of meta-stable intermediates with unprecedented temporal resolution.
• This technology offers a powerful tool for chemical and biochemical research requiring microsecond-level investigations.