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

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

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

First Chamber Mold Design

Chamber Mold Design Update

Side by Side Comparison

PDMS Testing Results

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.

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

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.

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

Cell Culture Pugh

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

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

Mechanical Strain Pugh

Actuator System Model

Rack and Pinion System Model

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

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

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

Budget

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!