Summary

Biomedical blood cell shearing device machine design.

While I was employed at the student machine shop at UC Davis my supervisor arranged for me to work on a design project with Anthony Passerini and his students in my "spare" time. This ended up being quite a complex little machine that was designed to apply known shear forces to a fluid through a rotating cone.

The design was mostly an attempt to recreate the cell shearing machine constructed by Blackman for his 1998 dissertation work at the University of Pennsylvania. His machine is somewhat documented in his dissertation and accompanying papers, but not in enough detail for full reproduction.

The design criteria for the tolerances of the cone/fluid interaction were extremely tight and most of the work was spent figuring out ways to ensure the relative dimensions of the cone and plate.

The principle of operation is based around rotation of a shallow cone in a fluid which theoretically generates a linear variation in shear stress with respect to the height of the cone.