Controlling Flow Speeds of Microtubule-Based 3D Active Fluids Using Temperature

Area of Science:

• Biophysics
• Microfluidics
• Soft Matter Physics

Background:

• Kinesin-microtubule systems form active fluids with complex flow dynamics.
• Controlling flow speed in these systems is crucial for microfluidic applications.
• Current methods often require sample redesign for speed adjustments.

Purpose of the Study:

• To present a novel method for tuning the flow speeds of 3D active fluids.
• To enable in situ and dynamic control over fluid flow rates.
• To explore the application of temperature as a control parameter.

Main Methods:

• Utilizing temperature variations to modulate kinesin motor activity.
• Employing kinesin-driven microtubule networks in a 3D active fluid.
• Characterizing flow speed changes in response to temperature cycling.

Main Results:

• Demonstrated in situ tuning of flow speeds within a 4-8 µm/s range.
• Achieved dynamic control, enabling periodic fast and slow flow by cycling temperature.
• Confirmed the Arrhenius characteristic of the kinesin-microtubule reaction governs speed control.

Conclusions:

• Temperature offers a versatile tool for controlling active fluid dynamics.
• This method allows for valve-less, locally tunable flow rates in microfluidic devices.
• The findings pave the way for advanced, dynamically controlled microfluidic systems.