1. The Ability to Walk Across Water
BY TREVOR WEEKS, JAIMING LIU, YOUSSEF ALI, JORDAN WOODWARD

2. Table of Contents Introduction Specifications and Target Audience
Concept Generation and Evaluation
Technical Analysis
Development
Testing

3. Gantt Chart

4. Our Mission and Problem Statements
To effectively communicate in order to achieve long term goals
Problem:
To design, build and test an ergonomic device, such as a buoyant shoe, as well as market it to a large consumer base of young adults aged years enabling them to walk across still or slow moving bodies of water ranging from pools and ponds to streams and lakes for recreational and transportational use while being user friendly all at an optimal cost.

5. Stakeholders? Possibly You!!
Professor
Classmates
Angel Investors
Landfill Operators
The User

6. Importance of Dryness? (1 low / 10 high)
Survey Results
Interested?
Gender?
Age?
Importance of Dryness? (1 low / 10 high)

7. Importance of Mobility? (1 low / 5 high)
Survey Results
Importance of Mobility? (1 low / 5 high)
Life Expectancy?
Amount of Use?
Type of use?

8. Design Specifications
lbs of supported weight (Tester was at max weight)
HIgh portability
Easily mountable and demountable
Strap mount fitting foot sizes to 15 (financial constraint: excluded in prototype)
Lifespan of 1-3 years
Durable: withstanding drops and normal wear and tear
User must be able to swim (Indicated by safety warning on marketed product)
Durability:
withstand drops
survive normal wear/tear
water-proof
Variety of colors
Provides a safe experience for the user
EPA and CPSC compliant: “consumer products safety standard described in section 7(a), 2056(a) “ (CPSC)^1
ISO certified: “customers are far more likely to contact a company if it uses an ISO 9001 logo in the marketing of its products or services” (ISO)^2

9. Potential Solutions Water bottles duct taped together Styrofoam shoes
Wood foot canoes
Hamster floating ball
Self buoyant water skis
Inner tube

10. Preliminary Design Sketches

11. Pairwise Component Comparison
Comparing specs to determine relative importance

12. Concept Scoring
Comparing each design in terms of their ability to meet design specs

13. Selected Design: Styrofoam Shoes

14. Polystyrene Shoes Physical Quantities
<Product was re-dimensioned from these original dimensions per block

15. How the System Works User wears the product like shoes
User walks with product like shoes
poles are built in to provide user with assistance
MENTION HOW SIMPLE IT IS!!!

16. Buoyancy Force Calculations
Unknown Variables:
density of the material
volume covered by water ^1

17. Buoyancy Force and Differing Densities

18. Academic Reference
“The deformation dependences of the shear stress obtained for these polymers became non-monotonic with rising deformation rates. This was characteristic of the reversible destruction of the polymer structure which increased with growing rates of shear. The maximum on the shear stress vs. deformation curve enabled the ultimate shear strength to be determined as a specific point on this curve. The ultimate shear strengths were reached at a deformations of several hundred percent, while steady flow conditions were attained at deformations of several thousand percent” ^3
(G. V. VINOGRADOV Institute of Petrochemical Synthesis of the Russian Academy of Sciences )
READ THIS AND NOT THE SLIDE:
“in this quote by russian scientist Georgi Vinogradov, he explains how polymers, such polystyrene, are able to withstand shear force (stress) and melts (at high temperatures) little to no permanent deformation. (example: styrofoam is a great insulator of heat or cold) Compared to other polymers, polystyrene is fairly average in these categories

19. Young’s Modulus (elasticity)
(makeitfrom) ^2
tyttt

20. Density and Cost Effectiveness
^3,^4

21. Tipping and Structural Engineering
Object Static Stability depends on:
The center of gravity (G), through which gravity exerts a downward force equal to the displacement of the object
The center of buoyancy (B), being the center of the underwater volume of the object, whose upward thrust counteracts the effect of gravity acting through G
The center of distance (Gz) between G and B
(GZ curves)^4 ^5

22. Bill of Materials

23. CAD Sketches

24. First Completed Prototype

25. https://drive.google.com/open?id=0B_zOaLuuFZoyaDBaQ0czT1RzLVk
First Trial Results
00:45

26. Problems and Solutions
Low Stability
Water wrapped in bubble wrap
PVC pipes to help walk across water
Nowhere to secure feet for maximum stability
Carve a place for the foot in each block

27. Conclusion
We were able to complete walk across the pool successfully in 2:50
Minor improvements to be done in order to advance to production level

28. How we plan to sell the product
Materials
polystyrene
protective hard coating
Upgrades
transportation handle
removable supports
Cost
high volume = low cost
Marketing
coastal areas
warm climates
United States

29. References https://www.cpsc.gov/PageFiles/105435/cpsa.pdf
Vinogradov, G. V. and Belkin, I. M. (1965), Elastic, strength, and viscous properties of polymer (polyethylene and polystyrene) melts. J. Polym. Sci. A Gen. Pap., 3: 917–932. doi: /pol

30. Image References http://byjus.com/physics/buoyancy/

31. Questions?