Stress and Strain: A Shoe Design Challenge (en español)

There are thousands of different types of shoes and just as many engineers working to develop new styles and improve existing designs. Engineers consider many variables when designing shoes: the material type for durability and function, anticipated shoe stresses and strains, the health and safety of the shoe wearer, and the shoe's aesthetics, among others. Engineers often work with podiatrists (foot doctors) to design high-tech shoes that are safe, comfortable and stylish. Mechanical engineers apply principles of physics to analyze, design and manufacture mechanical systems, including new shoes. Materials engineers—specialists in the structure of materials and their properties—select and design the best combination of materials for shoes.Examples of heeled shoes.CopyrightCopyright 2007 (left) James Zarske, used with permission; (right) Lauren Cooper, ITL Program, College of Engineering, University of Colorado Boulder

Procedures Overview

Students design and build high-heeled shoes using simple materials. Then, they test and redesign their shoes to provide maximum comfort and stability for the wearer.

Procedure

1. Organize the students into groups of three.
2. In their groups, have students discuss for 3-4 minutes the properties that make up a good shoe (that is, flexible, comfortable, stylish, durable, etc.).
3. Then, lead a brief class discussion on the same topic, specifically discussing stability, what the shoe will be used for, how durable it needs to be, its comfort, etc.
4. Tell students that they will be making high-heeled shoes from the materials listed above (show supplies to students). They need to make a pair of shoes to fit one member of their team, then that member will complete a "shoe walk" through an obstacle course.
5. Have student groups brainstorm ideas for their shoes (10 minutes), sketching out viable ideas on paper. The shoes should meet the following requirements:

• At least a two-inch heel (at the highest point).
• Must stay on the foot without being held on by the other foot or a hand.
• Must be a matching pair (left foot and right foot).Shoes under stress!CopyrightCopyright 2007 Lauren Cooper, ITL Program, College of Engineering, University of Colorado Boulder

6. After each group has agreed on a shoe design, have students check their ideas with a leader before they begin building. Make sure they have a plan for making the shoe fit, holding it on, making sure it is the right size, keeping the heel attached, etc.

Please note: for the next step, the instructor(s) should supervise the use of the hot glue guns and utility knives at all times. If necessary, cut/glue the material for students.

7. After designs are approved, students may begin to build their shoes. Allow 15 minutes for building.
8. Once all students have fabricated their shoes, have them complete a short obstacle course—walk around the classroom, step up on books, softly jump, etc.—to see which shoes hold up best. Allow 5-7 minutes for the "shoe walk" through an obstacle course.
9. After the obstacle course is completed by all groups, give students a chance to improve their shoe designs, addressing any flaws they noticed in the testing. As time permits, have students continue to test their shoes as they see fit.

Wrap Up - Thought Questions

• Which aspects of your design worked well? Why?
• Which aspect did not work well? Why not?
• What other supplies could you have used to build your shoes? How would you have used these additional materials?

This resource was modified from Fancy Feet! Stress & Strain Forces in Shoe Design to create a shorter, more streamlined version suitable for informal learning settings.

This resource is also available in Spanish.