SummaryStudents become familiar with the engineering design process as they design, build and test chair prototypes. The miniature chairs must be sturdy and functional enough to hold a wooden, hinged artist model or a floppy stuffed animal. They use their prototypes to assess design strengths and weaknesses.
Engineers build prototypes for their creations before starting actual production. Prototypes enable engineers to assess design strengths and weaknesses through testing and so they can redesign to achieve successful end products.
After this activity, students should be able to:
- Describe and follow the steps of the engineering design process.
- Assess prototypes for strengths and weaknesses.
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Each TeachEngineering lesson or activity is correlated to one or more K-12 science,
technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN),
a project of D2L (www.achievementstandards.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics;
within type by subtype, then by grade, etc.
Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.
All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).
In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.
- Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment? Thanks for your feedback!
- Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment? Thanks for your feedback!
- Identify and explain the steps of the engineering design process, i.e., identify the need or problem, research the problem, develop possible solutions, select the best possible solution(s), construct a prototype, test and evaluate, communicate the solution(s), and redesign. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment? Thanks for your feedback!
- Demonstrate methods of representing solutions to a design problem, e.g., sketches, orthographic projections, multiview drawings. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment? Thanks for your feedback!
- Describe and explain the purpose of a given prototype. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment? Thanks for your feedback!
- Identify appropriate materials, tools, and machines needed to construct a prototype of a given engineering design. (Grades 6 - 8) Details... View more aligned curriculum... Do you agree with this alignment? Thanks for your feedback!
Each group needs:
- 10 meters of 18-gauge wire for each prototype (jewelry wire seems to be the least expensive, available at craft and bead stores or online)
- My Chair Design Journal, one per student
To share with the entire class:
- measuring tape
- soldering iron (or wire finer than 18-gauge to secure main chair wire structure)
- wooden artist model or floppy stuffed animal
Engineers are responsible for designing everything in the human-made world. What might this include? (Have students name a few items.) Yes, they design airplanes, bridges, cars, computers, computer keyboards, etc. It's pretty obvious that you would need someone to design these things.
Engineers are also responsible for designing the less obvious products. How about boxes? Teams of engineers are responsible for designing cardboard boxes to serve very specific purposes. What types of things do you think they consider as they design boxes?
- What will the box be holding?
- Will the box be shipped?
- Is the cargo delicate?
- Can it spoil?
- How high will the boxes be stored? How much weight must each box need to hold?
- What could happen if the boxes are not tested before being used?
What could happen if the box is not sturdy enough for the cargo?
- The cargo could become ruined.
- The company shipping the cargo could lose money.
- If liquid, the cargo could leak and pollute the surrounding environment.
- If the cargo is ruined or unable to make the trip, trouble could arise for the person who ordered it.
You can see that a lot of thought must go into each item that is designed. The design of the box changes depending on what is inside. You could have two items that require the same size box, but the box would need to be different because one box is for a bottle of liquid medicine and the other box is for pens. How do you think this would affect the box design?
Think about a chair. It might be hard to imagine that engineers are still designing chairs considering how long they've been around, but think of a baby's high chair vs. a chair in a doctor's office. What factors must engineers consider as they design chairs?
- Where will the chair be located? (kitchen/doctor's office)
- How often will the chair be used? (3 x day/all day)
- Will people be doing anything else as they sit in the chair? (eating/reading)
- Will this chair get dirty often? (yes/hopefully not)
- Who will use the chair? What are the physical characteristics of the user(s)? (under 30 pounds/possibly hundreds of pounds)
The answers to these questions helps to dictate the design. For example, a chair in a doctor's office can be covered in fabric. But, this would be a bad idea for a baby's high chair since it gets so dirty every day.
For the next few weeks you will act as engineers. You will work in teams to design and build a chair prototype. You will outline where your chair will be located, who will sit in it, etc. Then, you will design and build a prototype. As you work, you will follow the steps of the engineering design process, and record your design process in an Engineer's Journal. You will use wire for your chair prototype, but think about what kind of materials you would use when you turned your prototype into a real chair.
human factors: A branch of applied science that is concerned with how products should be designed so that they are most effective and safe for people.
prototype: A working model that is used as an example for a later stage version.
Before beginning the activity, lead a discussion with the class about engineering and what engineers do. Students should know that engineers follow the steps of the engineering design process as they work. The basic steps are: identify the problem, brainstorm ideas, choose and plan the best idea, create a prototype, test, and redesign.
Before the Activity
- Have examples of chairs of different designs.
- Gather materials and make copies of the My Chair Design Journal.
With the Students
- Guide students through the brainstorming process to learn about brainstorming and start thinking about what really makes a chair. Have students write additional brainstorming ideas in an engineering journal. The final chair must be sturdy enough to be dropped from ankle-height, support a stuffed animal or a hinged, wooden artists model, and appear to be comfortable.
- Discuss the engineering design process with students. Explain that they will be designing a chair and building prototypes of the chair, following the steps of the engineering design process as they work.
- Explain to students that engineers work in teams and that one of the team members practices "human factors" to help them as they design. Human factors experts help engineers to design products and devices that will work for many people. In this case, they help engineers design chairs that are functional for people of differing heights and weights.
- Have students measure their heights and compare to the class mean.
- Students should next design an uncomfortable chair. Draw the chair design in their engineering journals before they build.
- Once they have designed an uncomfortable chair, have them build the chair with the wire. Use either a finer gauge wire to bind the wire or solder the wire.
- After students have built their chairs, bring together the class so each student can present his/her design to the group. This exercise helps to facilitate a discussion about features that make the chairs uncomfortable, which, in turn, helps students focus on what makes chairs comfortable.
- Next, have students redesign the chairs based on the knowledge they gained from their first prototypes.Test the chairs by placing the wooden model or floppy stuffed animal on them; a chair should be able to support the model/stuffed animal.
- Conclude the activity by giving each student time to present his/her redesigned chairs to the class. Require that they describe their chair's strengths and what they would change in the next iteration (next version, for improvement) of the design.
- As necessary, train students on the safe use of soldering irons. Or else, have only teachers use the soldering gun.
- What makes a successful chair?
- How do chairs fail?
- What is important to include into the chair's design?
- Where will your chair be located? Who will be sitting in it at that location?
- What would you change about your design if you were to build a real chair?
- What would happen if you built your chair without a prototype first?
Activity Embedded Assessment
Design Journal: As students progress through the activity, have them fill in the prompted questions and sketches in the attached My Chair Design Journal. Review their answers to gauge their comprehension of the subject.
Evaluation Rubric: Evaluate students using the attached Chair Design Matrix, which includes the criteria categories of brainstorming, imaging-planning-improving, creating, sharing and prototype design .
Additional Multimedia Support
Learn more about the engineering design process at https://www.teachengineering.org/engrdesignprocess.php
ContributorsAndrew Afram; Erica Wilson; Elissa Milto
Copyright© 2013 by Regents of the University of Colorado; original © 2006 Worcester Polytechnic Institute
Supporting ProgramCenter for Engineering Educational Outreach, Tufts University
Last modified: April 9, 2018