Hands-on Activity How to Design a Better Smartphone Case

Quick Look

Grade Level: 9 (8-10)

Time Required: 10 hours

(fifteen 50-minute class periods spread over 12 days)

Expendable Cost/Group: US $10.00

Group Size: 4

Activity Dependency: None

Subject Areas: Geometry, Science and Technology

NGSS Performance Expectations:

NGSS Three Dimensional Triangle

A photograph shows an iPhone with a cracked screen on a table with a ceiling lamp reflected in the glass.
Cracked screens cause user headaches. What does it take to design a better smartphone case?
Copyright © 2014 Iwan Gabovitch, Flickr (CC BY-2.0) https://www.flickr.com/photos/qubodup/15204217150


Engineers create and use new materials, as well as new combinations of existing materials to design innovative new products and technologies—all based upon the chemical and physical properties of given substances. In this activity, students act as materials engineers as they learn about and use chemical and physical properties including tessellated geometric designs and shape to build better smartphone cases. Guided by the steps of the engineering design process, they analyze various materials and substances for their properties, design/test/improve a prototype model, and create a dot plot of their prototype testing results.
This engineering curriculum aligns to Next Generation Science Standards (NGSS).

Engineering Connection

Materials engineers creatively design and use new and existing materials to develop innovative products and solve problems. They also use materials in new ways to solve problems. Materials engineering has existed since humans first settled, and arose from the need to create materials that enabled them to farm and build early cities. Today, whether we are wearing jewelry or clothing, consuming food, using electronics or sporting equipment, or using transportation—we all enjoy the fruits of past labor and research in the materials engineering field. Developments in materials engineering are predicated upon matching the chemical and physical properties of materials with product use and customer needs and desires.

Learning Objectives

After this activity, students should be able to:

  • Analyze various materials and substances for chemical and physical properties of matter.
  • Integrate knowledge of chemical and physical properties—including how tessellations affect strength—during the design process.
  • Design a prototype model by following the steps of the engineering design process.
  • Create a dot plot based on prototype testing.

Educational Standards

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.

NGSS Performance Expectation

HS-ETS1-2. Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering. (Grades 9 - 12)

Do you agree with this alignment?

Click to view other curriculum aligned to this Performance Expectation
This activity focuses on the following Three Dimensional Learning aspects of NGSS:
Science & Engineering Practices Disciplinary Core Ideas Crosscutting Concepts
Design a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.

Alignment agreement:

Criteria may need to be broken down into simpler ones that can be approached systematically, and decisions about the priority of certain criteria over others (trade-offs) may be needed.

Alignment agreement:

NGSS Performance Expectation

HS-PS2-3. Apply scientific and engineering ideas to design, evaluate, and refine a device that minimizes the force on a macroscopic object during a collision. (Grades 9 - 12)

Do you agree with this alignment?

Click to view other curriculum aligned to this Performance Expectation
This activity focuses on the following Three Dimensional Learning aspects of NGSS:
Science & Engineering Practices Disciplinary Core Ideas Crosscutting Concepts
Apply scientific ideas to solve a design problem, taking into account possible unanticipated effects.

Alignment agreement:

If a system interacts with objects outside itself, the total momentum of the system can change; however, any such change is balanced by changes in the momentum of objects outside the system.

Alignment agreement:

Attraction and repulsion between electric charges at the atomic scale explain the structure, properties, and transformations of matter, as well as the contact forces between material objects.

Alignment agreement:

Criteria and constraints also include satisfying any requirements set by society, such as taking issues of risk mitigation into account, and they should be quantified to the extent possible and stated in such a way that one can tell if a given design meets them.

Alignment agreement:

Criteria may need to be broken down into simpler ones that can be approached systematically, and decisions about the priority of certain criteria over others (trade-offs) may be needed.

Alignment agreement:

Systems can be designed to cause a desired effect.

Alignment agreement:

  • Represent data with plots on the real number line (dot plots, histograms, and box plots). (Grades 9 - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Summarize, represent, and interpret data on a single count or measurement variable (Grades 9 - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Students will develop an understanding of the attributes of design. (Grades K - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Students will develop an understanding of engineering design. (Grades K - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving. (Grades K - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Students will develop abilities to apply the design process. (Grades K - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Initiate and participate effectively in a range of collaborative discussions (one-on-one, in groups, and teacher-led) with diverse partners on grades 9–10 topics, texts, and issues, building on others' ideas and expressing their own clearly and persuasively. (Grades 9 - 10) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Represent data with plots on the real number line (dot plots, histograms, and box plots) in the context of real-world applications using the GAISE model. (Grades 9 - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Summarize, represent, and interpret data on a single count or measurement variable. (Grades 9 - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

  • Demonstrate proficient technical skills and craftsmanship with various art media when creating images from observation, memory, or imagination. (Grades 9 - 12) More Details

    View aligned curriculum

    Do you agree with this alignment?

Suggest an alignment not listed above

Materials List

To share with the entire class:

  • recycled or used items such as milk cartons, egg cartons, fabric, plastic, aluminum foil, toys, perfume, hair gel, lotions, coffee bags, construction paper, protein powder containers, bleach containers, Styrofoam, cloth, etc., for the Chemical and Physical Property Activity
  • 1 ream of copy/printer paper, for the Tessellations Activity
  • 1 package of brass brads or fasteners for the engineering design process, on Amazon
  • supplies for making prototypes such as Styrofoam, craft foam, paper, foil, plastic wraps, plastic or paper bags, modeling clay, silly putty, etc.
  • pad of chart paper and markers (for the Gallery Walk)
  • old cell plate lab glass slides from a science/biology teacher or purchased at Amazon, to serve as the smartphone screen surrogate; alternative: small mirrors from a dollar store or donated by others who have small mirrors they no longer want; these glass samples may more closely simulate cell phone size
  • zipper seal bags (for easy broken glass clean-up when testing the prototype protective phone cases)
  • colorful Post-it™ pads; 1 pad for every 2-3 students, such as from Amazon
  • colorful markers, pens, or pencils
  • Post-it Easel Pad Paper or regular easel pad paper and tape—1 sheet per group; note: school often provide paper for hall/doorway decoration
  • meter stick
  • masking tape, to mark the height for smartphone case testing
  • camera or cell phone, to capture slow motion
  • capability to show the class some online videos
  • access to computers with Internet access for student research

Worksheets and Attachments

Visit [www.teachengineering.org/activities/view/uod-2266-properties-matter-design-cellphone-case] to print or download.

Pre-Req Knowledge

A basic familiarity with the properties of matter and be able to list a few of them. An understanding of he nature of matter and the definitions of materials, objects, and fluids.


(Show the first 20 seconds of this 7:48-minute hook video, IPHONE with Shiloh and Shasha - Onyx Kids. Then introduce the engineering design challenge.) 

Today you are playing the role of materials engineers! Materials engineers design new materials, and they use these new materials and new combinations of existing materials to design innovative products and technologies based upon their chemical and physical properties. Their developments are predicated upon matching the chemical and physical properties of materials with the purpose of the products as wel as the end consumer's needs and desires. Your task is to design a smartphone case that can pass a drop test from 2 meters above the ground more than five times.

Throughout this design challenge project you will analyze various materials for chemical and physical properties and integrate this knowledge into the design of your prototype smartphone cases. You will also examine tessellations—structures made of the same shape being repeated multiple times. You will learn more about them when we get to the tessellations activity. You will be guided by the steps of the engineering design process, including brainstorming for idea generation, keeping an engineering design notebook, designing/building/testing a prototype, collecting data, improving/redesigning/retesting your prototype, and graphing a dot plot of your results.

First, let's see what you already know. Please complete this Activity Pre/Post-Quiz. If you don’t know some of the answers, that is okay! We will learn about all these topics throughout the activity. (Hand out the Activity Pre/Post-Quiz.) 



Physical properties are aspects of matter that can be observed or measured without changing the object’s chemical composition. Examples are mass, texture, shape, color, weight, density, strength, and state of matter—that is, whether it existis as a solid, liquid or gas.

Chemical properties are aspect of matter that can only be observed or measured by changing the object’s chemical composition via a chemical reaction. Examples include oxidation, reactivity, toxicity, and flammability.

Tessellations are patterns of repeated shapes with no gaps or overlaps. For example, a honeycomb is a tessellation of hexagons. Tessellations can be stronger than individual shapes; the interconnected nature of the patterns distributes force over the many shapes instead of focusing the force onto one shape.

Before the Activity

Read all instructions, gather supplies, and make copies of the handouts. Remember to make two copies per student of the Activity Pre/Post-Quiz to serve as the pre- and post-quizzes. Since this is a rather involved activity, it is recommended that you read the instructions and start gathering supplies at least three weeks before beginning the project with your class. 

Days 3-4:

Days 4-5:

  • Read through the Teacher Notes of the Tessellations Activity Packet.
  • Supplies needed: ream of printer paper, roll of tape per group or two, blocks or weights.
  • Before class, fold a piece of computer paper into a triangular-shaped tube and tape it shut. To do this, fold the piece of paper into thirds along its horizontal access, forming the three sides of a triangle. Then connect the ends of the paper forming one of the vertices; the other vertices are made up of your two previous folds. Or, make hexagons using the same method, except fold the paper into sixths, and so on.   
  • Repeat with a square tube, hexagonal tube, and octagonal tube. Remember, for the purposes of this activity, a tessellation needs an even number of sides; test students’ knowledge by asking them to make a tessellation of pentagons!

Days 6-8:

  • Print extra copies of the five-page Engineering Notebook in case students need fresh copies during the design and prototyping phase.

Day 9:

  • Ask a science teacher for a supply of used/unwanted biology cell slides to stand in for smartphone glass during prototype testing. Consider putting each glass with its prototype protective case in a zipper-seal bag to make clean-up easier.
  • Arrange for a testing location where groups can drop their "phones" from a 2-meter height. Mark this height with masking tape or a sticky note.

Day 10:

  • Prior to class, hang a piece of chart paper/easel pad paper/Post-It in each group’s work area. Divide it into two sections labeled “praises” or “some good things,” and “growth areas” or “some things to consider."

Days 11-12:

  • Ensure that the testing location is set up with a clear drop zone and 2-meter height marked.

With the Students

Days 1-2: Engineering Design Challeng Introduction

  1. Present the Introduction/Motivation content, including showing the first 20 seconds of the hook video, and administering the Activity Pre/Post Quiz.
  2. If desired, show other videos about phones and cases. Consider the following as possibilities; be sure to preview videos prior to showing the class.
  1. Introduce or review the steps of the engineering design process. Give each student the Engineering Design Process Wheel. Have them color each circle. You may want to have each student color each circle specific colors to make it easier when informally assessing their understanding of it. Give each student a brass brad. As you progress through the project, instruct them to get these wheel charts out and put the brad in the appropriate circle/step. This becomes your informal assessment of their understanding of the design process steps.
  2. Go over the Smartphone Case Expectations and Notes, which can be copied onto the back of the Engineering Design Process Wheel or displayed on a smartboard. (A copy is also in the Engineering Notebook.)   
  3. Have students organize into groups of four and decide on a team name.

Days 3-4: Chemical and Physical Properties Activity

  1. Distribute the Chemical and Physical Properties Activity Packet, one per student.
  2. Display the Chemical and Physical Properties Activity Packet page titled, "Chemical and Physical Properties Large Group Activity (Smartboard display)."
  3. For this part of the activity, ask a student volunteer to go to the board to serve as the class recorder.
  4. Ask students to pick a material, object, or substance such as a liquid, cloth, food, rubber, glue, oxygen, etc.
  5. Ask students to describe the item (stretchy, soft, does not react with skin, flammable, non-toxic, lightweight, etc.) Incorporate any suitable new vocabulary such as malleable, fragile, dense, lustrous, tough, ductile, water soluble. As descriptions are mentioned, direct the student recorder to write each description in the appropriate box (chemical or physical). Once the students seem to pick up on the pattern, have the class directly tell the recorder which box to write it in.
  6. Tell the class to fill in the boxes on their papers as the class recorder writes at the board.
  7. Repeat the second and third boxes in Part A.
  8. Follow the handout. When you get to Part D, pull out the old containers that you collected. Put them in different locations throughout the room. Have students get out of their seats to investigate the objects
  9. For Part E, provide students with computers with Internet access to research chemical and physical properties.

Days 4-5: Tessellations Activity 

  1. Consider kicking off this section with one ore more of the following videos. As with all videos, preview them before showing the class:
  1. Distribute the Tessellations Activity Packet, one per student. Have students work in groups to answer the packet questions.
  2. Expect student answers to vary depending on individual testing outcomes. For example, an answer to question 4 might be: "If we want a stronger product, we need to use the _________ (the strongest shape)."

Day 6-8: Ideation Activity

  1. Each day during the Ideation Activity, review the engineering design process by directing students to get out the wheel and put the brad in the appropriate circle/step.
  2. Ideation Activity: Have students brainstorm ideas as outlined in the Teacher Notes below. If limited by time, collect the Ideation Post-Its at activity end.
    • Hand out a pack of Post-Its to each table/group.
    • Tell students: “Every person, grab a Post-It note. During this three-part brainstorming session, you will come up with ideas about making your smartphone case. In Round 1, everyone sits in silence for five minutes as you think of ideas on your own and write them on your own Post-It note. In Round 2, each member shares his/her ideas and the team decides which idea to take forward. You may combine or alter the many generated ideas. You will have 10 minutes for this round. In Round 3, one person from each group hands a sticky note to the teacher containing the group’s decision. You have three minutes (or less) for this round. Are you ready?”
  1. Hand out the Engineering Notebook.
    • Review the Driving Question, the engineering design challenge, and the steps of the engineering design process. Have students answer Notebook question #1.
    • Review Smartphone Case Project Expectations and Smartphone Case Project Rubric, both in the Engineering Notebook
    • If collected, return Ideation Post-Its.
    • If desired, direct students to research making smartphone cases online. Lots of YouTube videos exist on this topic.
    • Have students answer Notebook questions #2-3.  
    • Have students complete a scaled drawing on the computer. A form is provided in the Engineering Notebook if you want it on paper first (or instead). Tell them they will need this for their Gallery Walk.
  1. Have students build prototype and complete Notebook questions #4-5 during the construction/building stage. 
  2. Hold teacher-team conferences at any point using the Teacher-Team Conference Sheet. If you do not have any adult classroom help besides yourself, you may need to come up with a seatwork assignment for the students to work on while you hold conferences.

Day 9: Testing and Review

  1. Have students take out their Engineering Notebooks. Review the engineering design process by having students get out their Engineering Design Process Wheel and put the brad in to the appropriate circle/step.
  2. Have teams test their prototype protective phone cases. Give them the old cell plate slides or small mirrors to mimic glass smartphone screens.
  3. During testing, have students use cameras/cell phones to record the drop tests in slow motion. As necessary, use a free app such as SloPro.
  4. Groups drop the phones from the same 2-m height. You may need to adjust this height depending on your building/classroom. 
  5. Have students complete Notebook question #6. Provide extra notebook or blank paper as needed so they thoroughly answer the question.
  6. As necessary, show students a few videos on dot plots. Below are some suggested good ones
  1. Have students put their data on the classroom board. Then have all students create dot plots of the class data, either paper or digital.

Day 10: Gallery Walk

  1. At the start of class, have each team place its prototype protective case, labeled sketch, and drop test data in its work area. 
  2. Inform students they will travel as a team to each team work area to examine and discuss the other projects as a way to help the other teams improve.
  3. Have each person grab a colorful marker, pen, or colored pencil  and a pack of Post-Its. Have them write their name on one and put it on your desk. You may want to use different colored Post-Its. Grade students based on the amount of usable information they provide, for example:
    • "This is good," "Awesome!," or "I don’t like this." are not helpful feedback to the designers when developing products. 
    • Direct students to make specific, helpful and actionable comments such as "The use of long wings appears to be a smart idea because I think they are the reason why your device fell slowly," :You may want to consider making your smartphone case lighter, smaller, etc.”    
  1. You may want to have each group count how many comments they received to ensure that each person provided feedback to each team. Give them time today or tomorrow to read the peer comments before moving into the redesign phase.

Day 11-12: Redesign

  1. Give teams time to redesign and rebuild their prototypes. Before rebuilding, have them discuss changes and produce scaled drawings on paper using the Scaled Drawing-Redesign Sheet or on a computer. If a group’s case survived the 2-m drop test, have them design a phone with a lower mass or design a phone that may be dropped from a higher height (that is, something suirable for construction workers). 
  2. Have groups retest their redesigned phones. 
  3. Administer the Activity Pre/Post-Quiz again, and then have students complete the Self, Peer and Group Evaluation.


chemical property: Determines how a substance will or will not chemically react; examples include oxidation, toxicity, reactivity, flammability or combustibility.

physical property: Measurable properties of a given substance such as hardness, color, flexibility, thickness, texture, malleability, stretchiness, viscosity, density, weight, bulkiness, odor, solubility; can be determined without relying on a chemical reaction.

tessellation: A shape repeated over and over again covering a plane without any gaps or overlaps; examples include honeycomb (hexagonal shapes repeating) and sheet metal work in manufacturing.


Pre-Activity Assessment

Pre-Quiz: Administer the Activity Pre/Post-Quiz. These eight open-ended questions covers properties of matter, desirable properties of smartphone cases, geometric shapes, and the engineering design process. Giving the same quiz at activity end enables a pre-/post-activity comparision of student learning gains.

Activity Embedded Assessment

EDP Wheel: Throughout the activity, aave students use the Engineering Design Process Wheel along with a brass fastener to track where they are in the process. This also enables teachers to informally assess students’ grasp of the overall arc of the process at each day/stage of the project.

Chemical and Physical Properties Activity: The packet for this sub-activity teaches students about chemical and physical properties and their importance. The end questions require student application of the information.

Tessellations Activity: Using the Notes and Answers for this sub-activity enables students to explore tessellations of different shapes and how they affect strength. The end questions require students to summarize their findings. 

Engineering Notebook: The five-page Engineering Notebook provides a means of informally assessing how well students are incorporating what they learned in the prior activities as they plan the design of their smartphone cases.

Teacher-Team Conferences: Student use of the Teacher-Team Conference Sheet helps the teacher informally assess who is mastering what content, how well teamk members are working together, and how they handle challenges.

Engineering Design Gallery Walk: Have students walk around the room making constructive comments and identifying areas for growth about the protective cell phone case prototypes made by their peer teams. Give students different-colored markers and Post-It notes so the comments remain anonymous while enabling the teacher to verify that every person contributed feedback. Evaluate students’ communication skills by the usefulness of the comments they provide.

Post-Activity Assessment

Post-Quiz: Re-administer the Activity Pre/Post-Quiz to make a pre-/post-comparison to assess how much students learned from the design challenge activity and its associated science and EDP topics.

Self, Peer and Group Evaluation: Have students use the Self, Peer and Group Evaluation to evaluate themselves and their group members based on work completed by each—even if absent—how well they were able to resolve conflict, share responsibilities, help each other, and produce a good product.

Investigating Questions

How can properties of matter including geometric design be incorporated in the manufacturing process to make better smartphone cases? (Possible answers: Using tessellations to make a stronger case, tessellations enable the case to absorb more energy, thus protecting the glass phone screen; a soft case can be better than a hard case at reducing the drop impact forces on glass, etc.)

Additional Multimedia Support



Get the inside scoop on all things TeachEngineering such as new site features, curriculum updates, video releases, and more by signing up for our newsletter!
PS: We do not share personal information or emails with anyone.

More Curriculum Like This

High School Lesson
Exploring Nondestructive Evaluation Methods

Students learn about nondestructive testing, the use of the finite element method (systems of equations) and real-world impacts, and then conduct mini-activities to apply Maxwell’s equations, generate currents, create magnetic fields and solve a system of equations. They see the value of NDE and FEM...


© 2018 by Regents of the University of Colorado; original © 2016 the University of Dayton, Central State University and Wright State University


Marjorie Langston; Maggie Demarse; Courtney Phelps; Jill Weaver

Supporting Program

Collaborative RET Program, the University of Dayton, Central State University and Wright State University


This material is based upon work supported by the National Science Foundation under grant no. EEC 1405869/1405923/1405950—a collaborative Research Experience for Teachers Program titled, “Inspiring Next Generation High-Skilled Workforce in Advanced Manufacturing and Materials,” at the University of Dayton, Central State University and Wright State University in Ohio. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Last modified: July 3, 2022

Free K-12 standards-aligned STEM curriculum for educators everywhere.
Find more at TeachEngineering.org