1. University of Pennsylvania Department of Bioengineering Aims/Objective & Hypothesis: UHMWPE Tensile Testing GROUP 2WB UHMWPE main component of THA acetabular cup Evaluate Material Properties of UHMWPE: 1.) Elastic modulus 2.) Ultimate stress 3.) Failure stress Under two conditions: Tensile loading at 25°C and 75°C Hypothesis: The material properties of elastic modulus, ultimate stress, and failure stress will be significantly different between the room and high temperature groups. Picture: ww.wheelessonline.com/image8/gapcup1.jpg

2. University of Pennsylvania Department of Bioengineering Methods, Protocol & Equipment: 1.24- 1” x 6” pieces of UHMWPE 2.20 mm/min strain rate 3.Three pilot trials 4.Seven room temp (25°C) and high temp (75°C) trials 5.Stress-Strain & Force-Displacement plots 6.Obtain values for specified material properties 7. T-test (α = 0.05) between groups Equipment: Instron GPIB Board LabView TM software Heating Apparatus IR Thermometer

3. University of Pennsylvania Department of Bioengineering Proposed Results/Findings/Deliverables: Primary DataSecondary Data Example Data Table Example T-test: Elastic Modulus

4. University of Pennsylvania Department of Bioengineering Potential Pitfalls: 1.  Voltage-temperature control unable to attain 75°C Use pilot trials to determine reachable temperature 2.  Inconsistent Temperature Environment Adjust proximity of heaters, voltage of heaters Take average temperature of before, during, and after test 3.  Groups fail to show significantly different results Increase test temperature to (material softens at 135°C, clamps functional up to 123°C) 4.  Sample slippage in clamps Adhere sandpaper to clamp faces Sand contact area of sample

5. University of Pennsylvania Department of Bioengineering Materials and Budget & Justification: UHMWPE sheet 24” x 6” x 0.04” (l x w x t) $ 5.14 - -30 to 82°C operating range Screw Side Action Clamps $ 1160.00 - max 1 kN Round Infrared Heaters (2) $ 171.50 - attain and preserve high temperature Low-Voltage Heating Elements (2) $ 123.28 - 110 V AC/DC Variable Voltage Output Transformer $ 240.95 - 700 VA power output (max 5 A) Handheld Infrared Thermometer $ 295.00 - accurately ascertain sample temperature without interference Styrofoam blocks $ 3.18 - partially insulated environment _______________ Total $ 1999.05