1. Mechanical Bioreactor Detailed Design Review
Amanda Castagnino
Emily Adams
Emily Wood
Natalie Nold
Simran Singh

2. Agenda Goals and Deliverables Updated Cell Chamber Design
PDMS Testing Results
PDMS Stiffening Investigation
PDMS Cell Culture Results
Cell Culture Pugh
Mechanical Strain Pugh & Actuator v. Motor Discussion
Additional Test Plan: Heat Cure Testing
Additional Test Plan: Cellular Response to Strain
Risk Assessment Update
Bill of Materials Update
MSD II Project Plan
Agenda

3. PHASE IV GOALS PHASE IV DELIVERABLES
Analyze testing related to the properties and cell compatibility of PDMS.
Investigate unexpected stiffening of PDMS in the incubator.
Choose the best options for mechanical strain application.
3-D print a pilot mold and use that mold to cast the first PDMS cell culture chamber.
Create plans for building and testing in the MSD II phase.
PHASE IV DELIVERABLES
Pilot PDMS mold of cell chamber.
Mechanical Strain Pugh Analysis
Cell Type Pugh Analysis
Updated Risk Assessment
Updated Bill of Materials
MSD II Project Plan

4. First Chamber Mold Design

5. Chamber Mold Design Update

6. Side by Side Comparison

7. PDMS Testing Results

8. Data Collected This is all the data that was collected.
Due to errors in testing equipment, the data cannot be used to say exactly what can be seen.
However, it can be used to show general trends.
Steps to be taken in the future to make the testing better.

9. PDMS Stiffening Investigation
Humidity
Hexenes
Chamber Testing
Assistance from Dr. Thomas Smith ~ Polymer Science Expert

10. Test Plan 10: Heat Cure Testing
Possible Heat Curing Conditions:
Room temperature for 48 hours
75 degrees Celsius for 2 hours
100 degrees Celsius for 35 minutes
Samples will be tested before and after incubation in humidity.

11. Cell Culture Testing - Recap
Decided to use 3T3 cells
Testing shows that 3T3 cells adhere to collagen ECM on PDMS and have viable growth
No real need for SHOX2 cell line for the purposes of our bioreactor
SHOX2 cells would have wasted time and materials due to need for testing its properties
1:1 Collagen to PBS ratio for ECM
Cells in this dish adhered best
Cells were easily able to be viewed under microscope

12. Cell Culture Pugh

13. Test Plan 11: Cellular Response to Strain
Varied strain percentage and strain frequency conditions once whole system is functional.
Tested ranges will depend on motor/actuator abilities.
Expected strain percentage up to 20%.
1 Hz is max expected frequency range

14. Mechanical Strain Detailed Design
Decided to take a step back a look at other design alternatives that could be operated by a motor
Came Up with 3 new motor driven designs
Conducted a Pughs Analysis

16. Mechanical Strain Pugh

17. Actuator System Model

18. Rack and Pinion System Model

19. Rack and Pinion . Actuator
Pros:
Dual chamber design with one motor
Cons:
More complex design
More time consuming development
Pros:
Simple design and construction
Time saver
Cons:
Risk in actuator overheating
More expensive
Need a second actuator in order to have dual chamber

20. Actuator - Top Straining Mechanism
Desired Specification:
Min 1 cm stroke
Have a max speed of >1 cm/sec
Max 5 lb Load
100% Duty Cycle

21. Risk Assessment Update
Rack and Pinion - Motor more robust
Actuator- More restrictions
Straining Mech. stops working d

22. Budget

24. This will allow us to spend more time on the user testing activities!
If an actuator is purchased, we can bypass mechanical strain design activities.
This will allow us to spend more time on the user testing activities!