Understanding the Bio-particle Behavior in Spiral Channels: The ultimate goal of this project is to unravel the physics of cell/sperm sorting in a device with spiral channels and understand how some bio-particles order themselves in the device. Sperm separation is a fundamental process for in-vitro fertilization (IVF) using sperm from testicular biopsies. For sperm preparation to start, we need to segregate sperm from unwanted particles (RBC, WBC, etc.) using inertial focusing technique. The mechanism by which sperm focuses is not known completely. Sperm cells show remarkably different focusing behavior compared to other cells (Ellipsoid, Cylinder, Red Blood cell, etc.). This phenomenon has fascinated our interests as researchers, raising questions like: How and why do various particle shapes find their equilibrium position and where does this difference come from? We have chosen spiral channels over other designs because of the property of curved channels to create an additional secondary flow effect known as Dean vortices. The dean vortices accelerate and modify particles’ inertial migration process for better cells focusing. By carrying out particle simulations that mimics the behavior of a living cell in the device coupled with experimental analysis, we (Brady Goenner and I) aim to elucidate physics principles governing sperm focusing to understand asymmetrical particle focusing behavior in the spiral channel.

Automated Device for Sperm Purification: NSF funded microfluidics project. The work involves building and developing rapid, highly automated, and controllable instrumentation which will be capable of isolation and enrichment of Sperm cells from patients with low sperm counts for in-vitro fertilization (IVF). We aim for our system to both increase pregnancy rates of infertile couples and provide separations faster than anything that is currently available on the market. The project is done in collaboration with the Andrology Clinic at the University of Utah and with the Salt Lake-based startup company NanoNC.


Particle sorting in a Straight Channel vs Spiral Channel [Sorting algal cells by morphology in spiral microchannels using inertial microfluidics, Allison Schaap, et al (2016)]