Unbeweavably Strong! Creating Strong Structures from Weak Materials
Design challengeCopyright Brennan Cruser
Students are introduced to the real-world problem of backpack straps breaking and the challenge of developing an eco-friendly strap to replace a broken strap. The goal is to use the engineering design process to develop a replacement strap using paper (a weak material) by changing its structure to make it strong enough to hold up to 7 kilograms, the recommended maximum mass for a fifth grader’s backpack. Students work through the design process to explore how structure affects strength while also considering eco-friendly solutions. Instead of throwing away a backpack and contributing to landfill waste, students focus on creative, sustainable ways to repair and reuse materials.
Engineers change the structure of materials to improve how they perform. Structural engineers design and test materials like metal cables to make bridges and buildings stronger and safer. Materials engineers work on a much smaller scale, changing the internal structure of material, even down to the arrangement of atoms, to improve properties such as strength, flexibility, and durability. When solving real-world problems, engineers think carefully about how structure affects function. They test different arrangements, patterns, and treatments to find the best combination. By changing a material’s structure, they can create solutions that meet the exact needs of a specific challenge or environment.
At the end of this activity, students should be able to:
- Describe how a change in the physical structure of a material can alter its physical properties.
- Design a simple experiment to test the effects of force on an object (in this case a strap made of paper).
- Develop a hypothesis.
- Identify and change the variables in an experiment.
- Graph the data from an experiment.