Engineering Design Task 1: Passive Vaccine Storage Device

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Teacher______________________________________________

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Student HandoutDesign Development and Evaluation Challenge 1: Passive Vaccine Storage Device

IntroductionImmunizations have become one of the greatest success stories in modern medicine, yet roughly 1.5 million children — or one every 20 seconds — still die each year from vaccine-preventable diseases. This is due in part to the sensitive nature of vaccines themselves, which spoil if they’re not kept at precise temperatures from manufacture to use. Immunizations rates are lowest in rural areas, such as Sub-Saharan Africa, where poor infrastructure and unreliable electricity delivery make reliable, life-saving vaccines hard to come by. Public health officials have begun working on devices to keep vaccines cold by minimizing the heat transfer to the vaccine without using an electric power source.

Take a few minutes to watch the video about the challenges of keeping vaccines at a proper temperature when there is no electric power supply available. As you watch the video, keep track of what you learned and any questions that you have about what is happening.

Things I LEARNED from the Video… Some QUESTIONS I have…

All matter is made of particles (atoms and molecules) that are constantly in motion. This means all the particles in an object have kinetic energy. The total amount of kinetic energy of the particles in an object is called the thermal energy. The more thermal energy an object has, the faster the motion of the molecules inside it. Another way to describe the kinetic energy of the particles in an object is the temperature of the object. Temperature is the average kinetic energy of the particles in an object. When the average kinetic energy of the particles in an object go up, the temperature will increase.

Heat is the energy transferred from an object at higher temperature to an object at lower temperature. Heat energy is always transferred from the object with a higher temperature to the object with a lower temperature When you touch an object that is “hot”, it means heat energy is transferred from the object (which is at a higher temperature) to your hand (which is lower in temperature). This also means that “cold” is not a property of matter. When you touch something that feels cold, it means that heat energy leaves your hand (high temperature) and transfers to the “cold” object (low temperature). When those objects reach the same temperature, they are in thermal equilibrium. When the objects are at the

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same temperature there is no net heat transfer.

Heat can also transfer between an object and the other matter that make up a system. For example, when you put something in an oven, heat is transferred from the air that are inside the oven to the food. Or, when you go outside on a cold day, heat is transferred from your body to the surrounding system (which is the air around you).

When designing containers to keep objects hot or cold, engineers consider how heat will be transferred between the materials inside the container, the container itself, and the surrounding air. One important factor is the thermal conductivity of the materials used to build the container. Thermal conductivity is a measure of the ability of a material to transfer heat. Materials with high thermal conductivity are called thermal conductors and materials with low thermal conductivity are called thermal insulators.

Things I LEARNED from the Reading The PROBLEM we need to solve…

The TaskIn this DESIGN DEVELOPMENT AND EVALUATION CHALLENGE you will use what you know about the transfer of thermal energy and the importance of tracking the flow of energy in systems to create a durable storage device that will keep a vaccine (falcon flask proxy) at a temperature range between 0˚C and 10˚C for at least 24 hours. Your device must allow the user to remove and replace the vaccine proxy. The device should be lightweight (must have a mass less than 5kg). It must be able be able to fit into a box with dimensions of 30cm x 30cm x 30cm. The client does not want to deal with water spills so it must be leak proof. The device must cost less than $25.00 to produce.

The fundamental scientific question related to this design is: How can we slow the transfer of thermal energy into or out of the passive vaccine storage device?Determine the Parameters of the DesignWith your group, fill out the chart below based on what you have read and watched so far.

Design GOAL… How this design will make a DIFFERENCE in the world…

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Design NEEDS… Design CONSTRAINTS…

The SCIENCE underlying the design…

Generate ConceptsCreate two different design concepts by filling out the chart below. Be sure to think about the transfer of heat energy and the importance of tracking the flow of energy in systems as you create your concepts

Name of Concept: Cost:

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Name of Concept: Cost:

Determine your Evaluation Criteria and Evaluate the ConceptsEach of the design concepts generated by your group members has strengths and weaknesses. When engineers have to choose between multiple design solutions, they make trade-offs between the strengths and weakness of their designs. This means that engineers must make compromises between characteristics of their design. In order to fairly evaluate the trade-offs in each design, engineers use a specific approach to evaluating their concepts.

As a whole class, use the design requirements, constraints, and ways to make the world a better place you listed earlier to identify five different evaluation criteria that all groups will use to evaluate each design concept. Add these evaluation criteria to the decision matrix below. Once you have determined the evaluation criteria that your group will use, rank order each concept on each criterion. Give the highest ranking concept a 1 and the lowest ranking concept an 8.

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Design Concepts

Evaluation Criteria

Score

Determine which Design Concept to PrototypeRecord the design you plan to prototype in the box below. This design might but one of the original concepts that you group generated and evaluated using the decision matric or a combination of several different designs.

Design Concept to Prototype Notes

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Design ArgumentYou will need to get feedback from your classmates about your design before you start to build. To convince them that you are on the right track, develop an argument that answers the question: Which design for a vaccine storage device that slows the transfer of thermal energy should go to prototype given the needs and constraints of the task?

You will present your argument on a whiteboard see figure at right). It should include:

1. A claim: This should be a picture of the design you plan to prototype. Be sure to include the science underlying the design.

2. Reasons: Explain why your proposed design is the best option in light of your evaluation criteria.

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Design Argument Presentation on a Whiteboard

Design Argumentation SessionShare your design argument with your classmates. Be sure to ask them how to make your design better. Keep track of their suggestions in the space below.

Suggestions from others on how to improve our design…

Good ideas I saw from other groups that I can bring back to my group…

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Changes to PrototypeIn the space below, write down the changes your group has decided to make to your prototype after the first argumentation session. Also provide a drawing of the prototype your group will build.

Changes my group will maketo our prototype before building…

Drawing of the Prototype we will build…

Safety RulesFollow all normal lab safety rules, In addition:

Make sure to be careful with any sharp objects used for cutting materials, such as scissors or box cutters. These tools can pierce skin.

Ask your teacher about the procedure for cutting materials your class will use. Do not open the falcon flask. If water or ice spills, make sure to clean it up immediately. Make sure to clean up your work area when finished.

Build the PrototypeUse the resources available to build a prototype of your design. As create your prototype, keep track of how much of each material you use and any modifications you make to original design.

Materials Amount Cost Modifications made…

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Test the PrototypeYou now need to design and carry out an investigation to test how well your prototype works. Prepare a plan for your investigation by filling out the chart below. Your teacher must approve your plan before you can start collecting data.

We will collect the following data:

These are the steps we will follow to collect data:

I approve of this investigationTeacher’s signature Date

Collect and Analyze DataKeep a record of what you measure or observe during your tests in the space below. Be sure to analyze your data before you make any decision about the performance of your design.

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Measurements or Observations… Analysis of our Data…

Revise the DesignUse the resources available to improve the design of your prototype. As refine your design, keep track of how much of each material you use and any modifications you make to original design.

Materials Amount Cost Modifications made…

Collect and Analyze More DataKeep a record of what you measure or observe during your tests in the space below. Be sure to analyze your data before you make any decision about the performance of your design.

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Measurements or Observations… Analysis of our Data…

Revise the Design AgainUse the resources available to improve the design of your prototype. As refine your design, keep track of how much of each material you use and any modifications you make to original design.

Materials Amount Cost Modifications made…

Collect and Analyze More DataKeep a record of what you measure or observe during your tests in the space below. Be sure to analyze your data before you make any decision about the performance of your design.

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Measurements or Observations… Analysis of our Data…

Analyze your Data from All Your Tests You will need to analyze all the data you collected during tests before you can make any decision how well you design works. In the space below, create a graph that shows the difference in the performance of each version of your design.

Design Evalaution ArgumentDevelop an argument that answers the question: Why is your design a good way to slow the transfer of thermal energy into or out of the passive vaccine storage device given the needs and constraints of the task?

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You will present your argument on a whiteboard see figure at right). It should include:

1. A claim: You answer to the guiding question.

2. Evidence: An analysis of the data you collected and an interpretation of your analysis that supports your claim.

3. Justification of the Evidence: Explain why your evidence matters. Be sure to include information about your design specifications and the science concepts underlying your design. Design Argument Presentation on a Whiteboard

Design Evaluation Argumentation SessionShare your argument with your classmates. Be sure to ask them how to make your argument better. Keep track of their suggestions in the space below.

Suggestions from others on how to improve our Argument…

Good ideas I saw from other groups that I can bring back to my group…

Draft ReportOnce you have completed your research, you will need to prepare a design report that consists of three sections. Each section should provide an answer for the following questions:

1. Introductiona. What problem were you trying to solve?b. Why will a solution to that problem make a difference in the world? c. What were the requirements and constraints of the design?

2. Design Processa. What did you do to develop your product and why?

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b. How did you use the information from the materials test to help design the initial version of the product?

c. What did you learn from testing the product?3. The Product

a. What is your product? b. What is the science underlying the design?

4. Argumenta. Why is your design a good way to solve the problem given the needs and constraints of the

task?b. How do you know the design meets all the requirements and the constraints?c. Why does your evidence matter?

Your report should answer these questions in 2 pages or less. This report must be typed and any diagrams, figures, or tables should be embedded into the document. Be sure to write in a persuasive style; you must convince others that your design is the best solution to the problem.

ReviewYour colleagues need your help! Review the draft of their investigation reports and give them ideas about how to improve. Use the Peer Review Rubric to guide your review.

Submit your Final ReportOnce you have received feedback from your friends about your draft report, create your final design report and hand it in to your teacher.

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Materials Review

You may use any of the following materials during this challenge. Take a minute to examine all the different materials. You will also be given the results of some tests conducted on these materials. You may want to use some of the information from these tests to help you determine the advantages and disadvantages of using each material. Be sure to take notes about their characteristics and how you might be able to use them.

Materials Unit CostWater Bottle (8 oz) 1 Bottle $0.75Water Bottle (20 oz) 1 Bottle $1.00Duct Tape 50 cm $0.50Plastic Bag (Gallon) 1 bag $1.50Plastic Bag (Sandwich) 1 bag $1.00Foam Insulation Board 100 cm2 $2.50Sill seal 100 cm2 $1.00Batting 100 cm2 $0.50Cardboard Box 1 $1.00Aluminum Foil 100 cm2 $1.00Falcon Tube (with rubbing alcohol) 1 FreeIce 1 cube Free

EquipmentBox cutterScissorsRuler/meter stick Thermometer/temperature probe

Notes…

Results from Materials Test

Procedure1. Wrap a thermometer inside each material. 2. Place the material with the thermometer inside it into a hot car (to simulate the inside of a vehicle that

might transport the vaccine or a building used to store it with no air-conditioning). 3. Record the temperature inside each material at 5-minute intervals for 15 minutes.

Results

Material Thickness (cm) Temperature (oC)0 min 5min 10min 15min

Batting 2.0 44 53.8 59.7 63.6Sill Seal 1.0 44 60.0 69.6 76.0Aluminum Foil 0.5 44 61.7 72.3 79.4Foam Board 1.0 44 55.8 63.0 67.2Plastic Bag 0.2 44 61.2 71.5 78.4Plastic Water Bottle N/A* 44 60.5 70.4 77.0

Cardboard 0.5 44 57.5 65.6 71.0Control+ N/A 80 80 80 80

*The thermometer was placed into the plastic bottle and taped to the cap so that the thermometer did not touch the side of the bottle.

+The control temperature is the temperature of the air inside the car. This temperature is approximately 25 oC higher than the hottest temperature ever recorded on the Earth’s surface. The highest surface temperature recorded is 54 oC (129 oF).

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