Parts discussion


With a (somewhat) complete model sketched up, the group has a discussion on the specific parts needed. As the deadline is approaching, we needed to:
a) select which specific materials we need for each part
b) the type of material we need for each part
c) what vendors to buy from

The group decided on this parts list:



…and the order was placed!

Specific parts discussion (Motor)

With the complexity of the cell culture plate dynamics (size/cell type/etc), we needed to finalize how the motor can be interfaced with the bioreactor. Pete’s expertise helped us along the way. He suggested we use a stepper motor which will allow us to make precise movements that can perform the movement arc we need to achieve without being too pricey or complicated. Here is Pete’s diagram of the specific parts needed to interface it to the bioreactor:


The motor will work by rotating a cylindrical object back and forth instead of full rotations. These movement speeds and distances can easily be controlled with Arduino.


Internal design mechanics

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With the candidate bioreactor modeling underway, the group needed to figure out the mathematical measurements for achieving the range of shear stress we aim to perform. This range (tentatively 0.05-0.25, with 5-6 equal increments and one control) was extrapolated to the amount of movement the machine needs to perform. These measurements will be incorporated into the model. The next steps are to update the model to fit.

Updating 3D Model: Getting Into Specifics


With Mitch’s initial 3D model, Pete helped the group think about the specifics of how the model will work. This process included thinking about mechanism and movement mechanics and trying to fit them within this model and current design. This exercise was completed by projecting the current model onto the SMART whiteboard and drawing additions onto it.

Initial 3D Modeling

Screen shot 2013-10-17 at 2.35.58 PM Screen shot 2013-10-17 at 2.35.30 PM Screen shot 2013-10-17 at 2.35.03 PM

Mitchell has done a great job rendering our best candidate bioreactor model in 3D with Google Sketch-up. Although all the minute details and kinks are not figured out, this provides a great basis to work with and delve into specific measurements and ideal shear force generation.


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With our needs/problem statement revised and having had a session on sketching, the group came together to present some candidate sketches to accomplish these goals. Here are some of Grace’s sketches/schematics