17 Questions
What is the formula for the time of residence (tr) of a particle in a channel for diffusive mixing?
tr = lchannel / vmean
In the context of passive diffusive micromixers, what does the diffusion time (tD) represent?
Time taken for particles to diffuse across the channel width
What is the minimum channel length required for complete diffusive mixing in a microfluidic system?
lchannel = vmean^2 / D
In a Y-mixer design, what is the role of laminar flow in achieving mixing?
Laminar flow helps in maintaining particle velocity
Which parameter determines the minimum channel length for complete mixing in a passive diffusive micromixer?
Diffusion coefficient (D)
How can the channel length be shortened in microfluidic systems?
By incorporating layering techniques
What happens when the diffusivity D is too small in the context of microfluidic systems?
The channel length becomes longer
Which technique is used for passive mixing by interdigitated lamella in microfluidic systems?
Layering technique
How is the minimum channel length reduced by layering techniques in microfluidic systems?
By stacking channels on top of each other
In the context of microfluidic systems, what effect does reducing diffusion length have on the channel design?
Reduces the minimum channel length
What is the main purpose of passive diffusive micromixers in microfluidic systems?
To achieve complete diffusive mixing
What is the primary advantage of using diffusive mixing in microfluidic systems?
It allows for rapid mixing of fluids without the need for active components or external energy sources.
In a Y-mixer configuration, what determines the extent of diffusive mixing between the two inlet fluid streams?
The channel geometry and dimensions after the junction.
What is the relationship between the diffusion length ($l_D$) and the time required for complete diffusive mixing ($t_D$) in a microfluidic channel?
$t_D = l_D^2 / D$
In a microfluidic channel with laminar flow, what is the diffusion length ($l_D$) typically defined as?
Half of the channel width.
Which of the following statements regarding passive diffusive micromixers is correct?
They rely solely on the channel geometry and diffusion to promote mixing.
What is the primary limitation of passive diffusive micromixers compared to active micromixers?
They require longer channel lengths to achieve complete mixing.
Explore the concept of Passive Diffusive Micromixers in the lecture on Microfluidic Systems - Bio-MEMS by Prof. Dr.-Ing. Uwe Schnakenberg. Understand the relationship between fluid properties, channel length, and diffusivity for efficient mixing within microchannels.
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