1. Mark Bradford Kevin Feeley Tony Martinelli Jeff Snyder Jacob Stephens

2.  Our sponsor sought a device capable of recreating in vivo conditions on cell cultures.  This device applies the mechanical stresses and strains that a particular type of cell culture would encounter within the body.  There is a device available commercially for this purpose; however, it is prohibitively expensive.  The purpose of this project was to design an alternative that is less expensive, thus enabling more researchers access to this type of machine.

3.  Must be considerably less expensive to manufacture  Must use standard well plates  Must be computer controlled  Must fit in an incubator  Must tolerate humidity up to 100%  Must be easy to use  Must allow easy access to well plate  Must measure forces applied to cultures  Must measure displacement applied to cultures  Must have high repeatability

4.  Several concepts were brainstormed  All concepts accomplish same functions but with different components  Those components included the clipping mechanism, driver, and type of well plate Figure 1: Clipping Mechanism Concept

5.  One of these concepts is sketched below Figure 2: Concept 2

6.  The clips secure the membrane to the stretch plate  The version shown below was determined to be the most user-friendly, while accomplishing their primary function Figure 3: Solid Model of the Clip

7.  The stretch plate transfers force from the driver to the membranes  The final version is designed for standard 8-well plates Figure 4: Solid Model of Stretch Plates

8.  The base constrains the stretch plate and holds the well plate in place  It was also designed to allow easy removal of the well plate Figure 5: Base with mounting sub-assembly

9.  The driver in the final design was picked to be a linear actuator  The driver provides force to stretch the membrane Figure 6: RRA-23 Linear Actuator

10.  Two sensors were needed, one that measured force and the other to measure displacement  The force sensor was a Load Cell strain gage, and the displacement sensor was a Baumer Inductive sensor Figure 7: Strain GageFigure 8: Baumer Inductive Sensor

11.  The machine needs to be computer controlled, and use software that is easy to use  National Instruments’ LabVIEW was chosen

12. CONCEPTSFINAL DESIGN  Clips  Used staples or screwed- down clamp  Well Plates  Used 6-well or 8-well plates  Driver  Used solenoid or piezoelectric motors  Base  Requires removal of stretch plate to access well plate  Clips  Uses ridged clamps  Well Plates  Uses 8-well plates  Driver  Uses electric linear actuator  Base  Well plate can be removed without touching stretch plate

13.  A prototype was produced, but a production run would use different materials  Of particular interest are the polymers whose resins are commercially available through Solvay . They provide the necessary mechanical properties and environmental stability needed for this product.

14.  The displacement sensor may need to be replaced with a more accurate linear laser sensor  The motor might interfere with the force sensor’s signal and may need replacement

15.  We would like to thank Cook Biotech, Dr. Omar El-Mounayri, Dr. Hazim El-Mounayri, and Mr. Rudy Earlson.