Teaching sequence

Work through this resource material in the following sequence:

10 minutes

Tune In: Meet Free 3D Hands

20 minutes

Find Out: Design process

25 minutes

Take Action: Testing components

5 minutes

Reflection

Learning intentions

Students will:

explore opportunities for designing, and how the nature of the opportunity impacts the materials chosen for the design.

Success criteria

Students can:

explain which materials are chosen for these devices and why
create tests to assess the suitability of materials for different purposes.

Tune In: Meet Free 3D Hands

Step 1

In the previous lesson, students explored a range of different assistive devices and their importance. Explain to students that they will now learn about who makes assistive devices and how they are designed.

Introduce students to Free 3D Hands. Free 3D Hands is a charity that creates 3D-printed assistive devices, such as hands, arms, and other tools, specifically designed for people with upper-limb differences. Their goal is to make assistive upper-limb devices available to everyone who needs them. They do this by:

making their 3D-printed designs freely available online
making sure their devices use parts that are readily accessible around the world, including in low-GDP and isolated communities
re-iterating their devices based on user feedback
funding their operation through grants, fundraising and philanthropy (so they don’t need to pass the costs onto the user)
providing support for building, fitting, modifying and fixing the devices.

Step 2

Provide the students with the Student Worksheet and, as a class, watch the following video.

Free 3D Hands - Creating Equal Access to Assistive Technology –(youtube.com/watch?v=9Dc8zZClPlA)

Ask students to make notes on the following questions on their worksheet:

What types of assistive devices does Free 3D Hands create?
How do they ensure the devices are affordable and custom-made?
Who can request these devices, and how does the process work?
What role does 3D printing play in making these devices?

Find Out: Design process

Step 1

Discuss the following questions with your students:

Why do we design things?
How do we know when we need something designed?
How do we know if it’s a good design or a bad design?
If we design something, and it turns out to be a bad design, what do we do?

Step 2

Explain to students that we call this process the design thinking process. This is the process that organisations like Free 3D Hands need to undertake to ensure their devices work for users. Introduce to (or review with) your students the 5 steps of design thinking:

Empathise
Define
Ideate
Prototype
Test & iterate

Provide students with the Student Worksheet. As a class, discuss each of the different stages and write a definition for them.

If you have a different design thinking process you have used with the class previously, you can swap that in here!

Explain to your class that the design thinking process:

is a cycle, and the process of testing often leads back into empathising (and getting a new or better understanding of the user’s needs), which starts the cycle again
often happens in small cycles within the larger project (for example, looking only at the fasteners for the kinetic arm is a design thinking cycle within the larger project of designing the kinetic arm).

Learning extension: Watch Malia from NerdForge design her own 3D-printed finger and identify the different stages of the design process throughout the video.

Step 3

Explain to students that today they will explore the testing phase of the design thinking process. They will investigate the materials and components used by Free 3D Hands in the various assistive devices they create. In pairs, ask students to look at the table on their Student Worksheet, compare the different types of plastic, and answer the questions below.

Why do you think Free 3D uses PLA to print their devices?
What are the downsides of using PLA for Free 3D Hand devices?

Once students have discussed the questions, ask them to share their ideas with the class. They may suggest that Free 3D Hands uses PLA because it:

is biodegradable and made from renewable resources, making it more eco-friendly
is cost-effective, helping keep devices affordable
is non-toxic and safe for skin contact
is easy to 3D print, with low fumes, precision, and a smooth finish
has high strength.

They may suggest that the downsides of using PLA include:

lower durability, meaning the devices won’t last as long
the low warping point means the devices could fail if they are left in a car on a sunny day or exposed to heat
the plastic could be lighter.

Explain to students that choosing materials or components in a design process often involves trade-offs. Usually, there is no perfect material, so designers need to consider what factors are the most important in their decision-making process.

Take Action: Testing components

Step 1

Let’s try the design process for ourselves. Show the class the following video, looking at the kinetic arm.

Kinetic Arm Requirement Demo – (youtube.com/watch?v=lTXqPxAPv2o)

While watching the video, encourage students to pay attention to:

the different materials they can see in the construction of the arm
how the arm functions
what the arm can, and cannot, do.

Step 2

After watching, ask students, ‘What is used to fasten the kinetic arm?’ (answer: Velcro). Followed by ‘Why do you think Free 3D Hands chose Velcro as the fastener?’

Students may mention that Velcro is:

comparatively cheap
resistant to water, heat, cold and chemical damage
long-lasting
comfortable against the skin
free of sharp parts, parts that can break, or choking hazards
easy to resize and adjust if the arm changes size due to swelling, weight loss/gain, medical conditions, or clothing
very light
repaired by sewing
easily sourced
available in different colours and can be customised.

Step 3

Ask students to consider alternative fastener options. They might suggest:

leather straps and buckles (like shoes)
laces (also like shoes!)
magnets
buttons
a zip
press studs
temporary glue

Step 4

Put students in groups of 3 or 4 and ask them to choose an alternative type of fastener that could have been used for the kinetic arm. As a group, have them discuss the pros and cons of each type of fastener across these categories, and note down their ideas in the table on the Student Worksheet.

Students need to consider the following:

Cost: How expensive is it?
Durability: How long will it last? Will it maintain the same function?
Ease of use: Can the user manage on their own? How long will it take to do up?
Comfort: Could you wear it all day? Would it be comfortable?
Safety: Are there bits that could break or be sharp? Could you get stuck?
Adjustability: How adaptable would the fastener be to different shapes and sizes?
Weight: How heavy would it be? Little parts add up in weight!
Sustainability: Is it biodegradable? How is it sourced?
Repair and upkeep: How often will you need to replace it? Can you fix it? How hard would it be to find new parts?
Aesthetics: Does it look good? Can it be customised to the user?

Once the students have noted down their ideas for each type of fastener, ask them to:

compare the fasteners in each category
decide which type of fastener is the best option for that category
colour in the star for that fastener.

Whichever fastener gets the most stars ‘wins’.

Learning support: For this section, you could make different types of fasteners available to students and focus on their physical characteristics (for example, weight or ease of opening and closing with one hand).

Return as a whole class, and ask the students to share their results and justify their choices.

Numeracy extension: Ask students to research the cost of their chosen fasteners and the quantity needed for each kinetic arm. They could also research the product's expected lifespan and calculate the cost of replacing the fasteners over time. They may find that a more expensive fastener will last longer and yield long-term savings.

Reflection

As a class, identify which stages of the design thinking process you have engaged in during this lesson (and the previous lesson if you completed it!), in relation to an assistive device for someone with an upper limb difference. They might suggest:

empathise – looking at the needs and requirements of people with an upper limb difference
ideate – thinking about different types of fasteners that could be used
test – comparing Velcro to other fasteners to determine suitability

Ask your students to consider how having an involved end user would impact the design process.

Explain to the class the different ways Free 3D Hands support the involvement of the end user in the design process, including:

working with the end user to customise and fit the devices
making the plans and 3D printing patterns freely available so end users can modify the design to best suit their own needs
providing a range of devices for different applications.

Getting Hands-On

Go to

Summary

Learning intentions

Success criteria

Lesson Guides and Printables

Lesson Details

Skills Required

Curriculum Mapping

Resources Required

UN Sustainable Development Goals

Additional Information

Related Professional Learning

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