Unit Plan 8 (Grade 8 Science): Designing Thermal Devices

Focus: Construct and test devices that absorb or release thermal energy, using ideas about particles, phase changes, and material properties to improve performance. Students move through an engineering design cycle: defining a problem, setting criteria/constraints, generating ideas, building prototypes, testing, and revising.

Grade Level: 8

Subject Area: Science (Physical Science • Engineering Design • Energy & Matter)

Total Unit Duration: 5 sessions (one week), 50–60 minutes per session

I. Introduction

Students shift from explaining thermal phenomena to engineering devices that manage thermal energy. Using their understanding of particle motion, thermal energy transfer, phase changes, and material properties, they design small-scale devices such as insulated containers, cool packs, or warmers that either absorb or release heat. In teams, students define criteria (what “success” looks like) and constraints (materials, time, safety), then build, test, and improve their designs. Throughout, they collect temperature data, compare competing designs, and explain how their device works at the particle level.

Essential Questions

• How can we design a device that absorbs or releases thermal energy in a useful way?
• What criteria and constraints should we consider when solving real-world thermal problems?
• How do materials, particle motion, and phase changes affect how well a device stores or transfers thermal energy?
• How can data (like temperature change over time) help us compare and improve competing designs?
• Why is an iterative design process (plan–build–test–improve) important in engineering?

II. Objectives and Standards

Learning Objectives — Students will be able to:

1. Define a thermal design problem (e.g., keep a liquid warm/cold, protect an object from heat) and specify clear criteria and constraints (MS-ETS1-1).
2. Use knowledge of thermal energy, particle motion, state changes, and material properties to generate and sketch at least two design ideas for a device that absorbs or releases thermal energy.
3. Construct a prototype device using available materials (e.g., insulating materials, containers, substances that change temperature) while respecting safety and resource constraints.
4. Plan and carry out tests that collect temperature–time data on device performance, using data tables and basic graphs.
5. Evaluate and compare multiple design solutions using the same performance criteria, and suggest improvements based on evidence (MS-ETS1-2).
6. Explain how their final design works using particle-level reasoning, including how thermal energy is absorbed, released, or restricted, connecting to MS-PS1-4 and MS-PS1-6.

Standards Alignment — 8th Grade (NGSS-based custom)

• MS-PS1-6 — Undertake a design project to construct, test, and modify a device that releases or absorbs thermal energy.
• MS-ETS1-1 — Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution.
• MS-ETS1-2 — Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints.
• Supporting links to prior units:
  • MS-PS1-4 — Particle motion/temperature/state when thermal energy is added or removed.
  • MS-PS1-2, MS-PS1-3, MS-PS1-5 — Properties of substances, synthetic materials and their impacts, and conservation of mass (as background for choosing materials and understanding what changes in the device).

Success Criteria — Student Language

• I can clearly state the goal of my thermal device and the criteria and constraints for success.
• I can build a prototype that is safe, realistic with our materials, and aims to absorb or release thermal energy on purpose.
• I can collect and organize temperature data to see how well my device works.
• I can compare designs using the same criteria and say which one works better and why.
• I can explain how my device works using particle motion, thermal energy transfer, and materials in my explanation.