Invent a backscratcher
In the Invent-a-Backscratcher Challenge, students become product designers tasked with solving a very relatable problem: how do you scratch an itch you cannot reach? They’ll sketch, build, test, and improve their own useful invention while learning how engineers turn everyday problems into new products.
Primary
engineering, creativity, prototyping, empathy
Project Details
Theme
December | Product Design
Messy Level
1
Suggested Location
Classroom or lab
Prep & Classroom Structure
Before class, organize materials into a central “Inventor Supply Shop” so students can easily see their options. Pre-cut a few difficult materials, prepare enough scissors and tape for each small group, and consider placing materials in categories such as handles, connectors, and scratching surfaces.
I would not show students a finished backscratcher at the beginning. For this format, withholding the solution will likely produce more original designs; instead, focus attention on the problem and ask what properties their invention might need.
https://www.teachengineering.org/activities/invent_a_backscratcher
Useful prep:
Plan for pairs of students.
Put paper and pencils at each table for the design sketch.
Create a clear testing rule: backscratchers should be tested over clothing only and gently.
Prepare extra tape, tubes, and cardboard because those will likely be the most-used supplies.
Set aside 5–10 minutes at the end for testing and redesign.
Avoid materials with sharp points or rough exposed edges.
Create a display area where finished prototypes can be placed for the final gallery walk.
Instead of telling students how to fix their designs, prompt them with questions such as: “How will your design reach far enough?” “What could make the handle stronger?” “How will the scratching end stay attached?” “Is it comfortable to hold?” and “What would you change after testing it?”
Those questions keep the activity centered on engineering rather than simply making a craft. The lesson itself stresses that designs can take many forms and that sketches help students communicate and refine their ideas
What's happening: This project introduces product design and the engineering design process. Students begin with a real-world problem, develop an idea, communicate that idea through a sketch, build a prototype, and evaluate whether the finished product actually solves the user's need. Engineers also consider factors beyond basic function, including comfort, appearance, durability, material use, and ease of use.
Materials
Tape
String
Scrap cardboard
Paper towel tubes
Scissors
Glue
Optional recycled materials such as craft sticks, pipe cleaners, cups, foam pieces, yarn, or other classroom-safe supplies
Project Instructions
Introduce the problem: You have an itch in the middle of your back, but you cannot reach it. What could you invent to help?
Let students examine the available materials and talk with their partner about possible solutions.
Have each team draw a simple sketch of its backscratcher before building.
Ask students to explain what each part of their design will do.
Students choose materials and build their prototype.
Encourage them to think about length, strength, comfort, and the shape of the scratching end.
When the prototype is finished, test whether it can reach the middle of the back and perform its intended job.
Ask students to identify something that works well and something they would improve.
Give them time to modify the design and test it again.
Finish with a quick gallery walk so students can see how many different solutions were created for the same problem.
Class Video
Please share with teacher: