Abstract:
Recently my research group in the Microfluidics Laboratory at Purdue University has developed several innovative technologies with potential applications in the bio/medical/chemical/pharma industries. These are (i) droplet-based microfluidics, (ii) opto/electric particle manipulation and (iii) particle diffusometry. I will present the fundamental principles behind these methods, what their capabilities are, and what their potential uses are. The talk will review:
- Droplet-based microfluidics: we have developed all on-chip methods of pumping, mixing, and combinatorial chemistry. The most exciting recent development is our ability to produce a sequence of hundreds of droplets with a gradient of a desired compound. This technology is quite useful for constructing dose/response curves while consuming a minimum of potentially expensive samples and reagents as well as for minimizing human or even robotic involvement in constructing dose/response curves.
- Opto/electric particle manipulation: using lasers and electric fields we can capture, concentrate, manipulate and sort populations of micro- and nanometer-scaled “particles”. The “particles” range in size from single molecules (DNA, proteins, etc.) to nanoparticles (quantum dots, carbon nanotubes, nano-scaled polystyrene latex beads, etc.) to biological organisms (bacteria, mammalian cells, etc.). This novel technique combines features of optical trapping (OT) and dielectrophoresis (DEP) in an innovative, dynamic way using a simple parallel plate electrode configuration. Applications range from collecting desired cell populations to separating one size of particle from another.
- Particle Diffusometry: Through the Stokes-Einstein diffusion coefficient and the statistics of PIV, we can measure the effective hydrodynamic diameter of the particle increasing due to surface adhesion as well as viscosity increase due to rheology changes of the suspension. As an example we consider the degradation of insulin, a commonly used protein for patients with diabetes. We can discriminate intact insulin from degraded samples.
Bio:
Professor Wereley completed his masters and doctoral research at Northwestern University. He joined the Purdue University faculty in August of 1999 after a two-year postdoctoral appointment at the University of California Santa Barbara. During his time at UCSB he worked with a group developing, patenting, and licensing to TSI, Inc., the micro-Particle Image Velocimetry technique. His current research interests include designing and testing microfluidic MEMS devices, investigating biological flows at the cellular level, improving micro-scale laminar mixing, and developing new micro/nano flow diagnostic techniques. Although considerably outside the field of microfluidics, Professor Wereley used his flow measurement expertise to analyze the Deepwater Horizon oil spill in the Gulf of Mexico in 2010, serving on the US government’s Flow Rate Technical Group. His contributions to characterizing the disaster were recognized with the US Geological Survey Director’s Award. Professor Wereley is the co-author Particle Image Velocimetry: A Practical Guide, 3rd ed (Springer, 2018). He is on the editorial board of Experiments in Fluids and is an Associate Editor of Springer’s Microfluidics and Nanofluidics. Professor Wereley has edited Springer’s recent Encyclopedia of Microfluidics and Nanofluidics and Kluwer’s BioMEMS and Biomedical Nanotechnology.
