Undergraduate Research Project

Undergraduate Research Project (AY 26-27)

An Investigation of critical Archimedes values for particle capture and release in a channel cavity 

Faculty Advisor

Robert Davis
Department of Chemical and Biological Engineering, University of Colorado Boulder

Grad Mentor

Henry Lutz
Department of Chemical and Biological Engineering, University of Colorado Boulder

Project Description

Microfluidic devices are commonly used for the separation of cells, drops, or particles based on size or rigidity factors. Taking inspiration from single-cell imaging platforms, a similar separation behavior can be achieved in a well cavity using gravity as a primary driving force. Our group has previously studied the trapping and release behavior of deformable drops in a well cavity, using both experiments and simulations. The goal of the current project is experimental determination of critical nondimensional parameters to trap and release solid particles, with comparison of the results to previously observed drop behavior. The non-dimensional parameters characterize the viscous and gravitational forces present within the system, with the primary parameter being the Archimedes number (ratio of gravity to viscous forces). By working with several different cavity geometries and a variety of particle sizes, the student will investigate the influence of well cavity geometry and particle size on trapping behavior and determine the critical Archimedes number above which capture occurs. Video analysis will be conducted with Python and FIJI to track the particle position and velocity over time during the trapping/release experiments. This trajectory analysis will aid in our understanding of the physics of the particle behavior in the well cavity. Through this project the student will gain first-hand experience in fluid dynamics research and video analysis. Applications of this work are for microfluidic separations for cells and microparticles with special interest toward cell isolation for microscopy applications. Future work on this project will explore scaling down experiments to the micron scale for cellular applications. 

Time Expectation

At least six hours per week for the fall semester (with option of continuing in the spring semester or beyond) in blocks of at least 2 – 3 hours agreed by the Grad Mentor.

Minimum Qualifications

Majoring in Chemical and/or Biological Engineering, Biomedical Engineering, or Mechanical Engineering. Completion of a course in fluid mechanics or biotransport.

How to Apply 

Send an email with cover letter and CV (including student id number) to Robert.davis@colorado.edu by 8/31/2026.

Financial Support

The position includes a stipend of $1500 per semester. Alternatively, the student may undertake the project for credit as Independent Study, without a stipend.

Posted 08.18.26