Increasing Microdialysis Recovery using COMSOL and Microfluidics

Student: Patrick Pysz

Degree: M.S., December 2019

Major Professor: Dr. Julie Stenken

Research Area(s):

Biological Materials and Devices

Nanoscale Materials and Devices

View Research Quadslide

Background/Relevance

  • Microdialysis (µD) – diffusion based sampling technique for in vivo collection.
  • Requires extensive in vivo calibration.

Innovation

  • Predict µD relative recovery (RR).
  • Simulate new µD device with improved relative recovery.

Approach

Key Results

  • µD herringbone linear channel simulated with COMSOL
  • Concentration boundary layer collapsed without increasing the fluid linear velocity.
  • 16.9% increase in RR above simple linear channel.

Conclusions

  • COMSOL template µD model developed for custom geometries.
  • Characteristic length scales for diffusion and advection were optimized for a linear-looped µD probe yielding a 16.1% relative increase in RR at a 1.0 µL/min flow rate.
  • Concentration boundary layers were shifted using a herringbone mixer µD probe design with a 16.9 ± 0.7% relative increase in RR over seven different flow rates.
  • Linear-looped µD probes can be fabricated in PDMS with in-house fabricated polyethersulfone membranes. 

Future Work

  • Optimize herringbone geometry for further increases in RR.