How do we package our food? During this session you will introduce the concept of thermochromatic paints and ask your club to apply them to an engineered product.

in partnership with

We are smart consumersWe look at the salt, fat and calorie content of our food. We also look at whether it has been ethically produced and how potentially damaging its carbon footprint is. However, the packaging our food comes in is getting smart too.

Thermochromatic paints show a change of colour with heat. This activity looks at designing and manufacturing ’smart packaging’, which uses thermochromatic pigments to show the product is at the right temperature.

What you need

Paint brushes

Paint pots

Pigments (these can be purchased from www.mindsetsonline.co.uk product code IT9-007-FAM)

Acrylic base (any white or light coloured paint)

Paper

Paper cup (for hot liquids)

Thermometer

Hot water

Note for STEM Ambassadors: schools will have many of the items you need, so check with the teacher before your session. A risk assessment should be done before starting this activity.

The whole packageThis session

should fill a club timeslot as a one off project (or it can be used as part of a short term project if extras are followed).

2 The whole package

What to do Make up your paints – a small amount of the pigment mixed into the acrylic base (a white or pale colour is most suitable) will do.

Ask your group to think about how they might investigate the way the pigment changes with temperature (without using a Bunsen burner or naked flame as that would burn the paper!).

An easy way to get an idea of the transition temperature is to paint your paper cup and to fill it with warm water. At what temperature does the paint just start to change? (Perhaps start with cold tap water, adding boiling water a little at a time. Do follow the school’s usual health and safety procedures).

Set your group the following task:

The local supermarket manager wants to use thermochromatic pigments on the packaging for some food products. Which type of food or drink is most suitable?

You are to design and then manufacture packaging suitable for a food product that would spoil if kept too warm for too long (for example, dairy or meat products).

Some extras... There are many other elements that you could add to this activity:

Discuss the importance of fair trade, carbon footprints or recycling in big (and small) shops.

Make your own recycled paper. See: http://ecokids.ca/pub/index.cfm for a simple method.

Decide on a food product to sell in school, the STEM Club could be healthy sandwich providers.

Students must research, design and test flavours.

Branding and packaging should be developed; how can you incorporate the unique selling point of the thermochromatic pigments? CAD/CAM can be used to help the designs and manufacture of the packaging.

Curriculum links Using this activity you can discuss:

England Science: Earth and atmosphere, Energy changes and transfers

D&T: Design, Make, Evaluate

Scotland Technological developments in society

ExplanationIn theory, this type of packaging could be used to show if a product has been kept at the wrong temperature.

For example, has milk been kept out of the fridge? The pigment causes the paint to change colour.

However, when the pigment is heated it becomes transparent and the original colour of the base acrylic is revealed.

Unfortunately for this activity the colour change is temporary, so when the temperature returns to normal the colour will change back.

The whole package 3

Industry sector

Manufacturing

What I do on an average day 

Every day is different. On occasion, I might spend a whole day researching and designing a new product, process or system at my desk. Other days might involve building prototypes for experiments and carrying them out or visiting customer sites to assess a machine.

How I got here

I took maths, physics and design & technology A-levels. Following this I read Mechatronic Engineering at Leeds University where I gained a broad view of engineering and decided to follow a route into mechanical engineering.

I was able to get on a graduate scheme after university and have since moved through a variety of roles, from working with conveyor systems using rollercoaster technology at Heathrow Airport and playing (I mean developing) Action Man toys and games, to the role I have at present; designing optical sorting machines.

Who uses manufacturing?Sean BrennanMechanical Development Engineer

My favourite part of my job 

The most rewarding and enjoyable part of my job is designing a product and then seeing it being built.

The future

At present, I am enjoying engineering and worked hard to pursue research and development. I hope to be able to continue learning, have the opportunity to continue to work on exciting new innovative projects and hopefully fit more travel into my job.

What is engineering?

Everything in the world has some form of engineering associated with it. It can be used to make people's lives more enjoyable like developing a games console, to saving lives by developing medical equipment or solutions to problems in the developing world.

Engineering can be as simple as manufacturing the chairs you sit on, or as complicated as building a space station.

Handy hints Smart or intelligent packaging detects changes in the environment, which in turn cause changes in the packaging, such as a change in colour.

There is also ‘active packaging' that can prolong a food’s shelf life. This is done by removing oxygen or water and therefore slowing down bacteria growth.

Can your group find examples of these and other smart or active packaging in the local supermarket?

In the future, engineering may enable our shopping to be fast and stress free, using wireless technologies that notify the till what you have taken before you have to pay.

Royal Academy of EngineeringPrince Philip House, 3 Carlton House Terrace, London SW1Y 5DG

Tel: +44 (0)20 7766 0600www.raeng.org.ukRegistered charity number 293074

Generously supported by

www.baesystems.com/education

This is engineeringThinking about how we can be creative and apply the properties of thermochromatic paints to packaging and ways of manufacturing them is a great illustration of how engineering affects us without many of us even realising it.

Engineers have a huge input with respect to our food, and manufacturing engineers in this and other industries are essential. Manufacturing engineering can be taken at many universities, with entry requirements including A levels, Advanced Diplomas and Scottish Advanced Highers (www.ucas.com).

Related fields: Materials science and agricultural engineering.

However, we might not be able to manufacture food or products at all without land-based service engineering (www.apprenticeships.org.uk). This Apprenticeship deals with the maintenance and repair of a range of mechanised equipment used in agriculture and other land-based industries. Land-based service engineers work to solve problems using a combination of scientific, technical and engineering knowledge.

In Scotland visit www.apprenticeshipsinscotland.com and in Wales wales.gov.uk/apprenticeships.

Extra mathsIf 30% of students at your school buy your thermochromatic pigment product how many products would you be able to sell?

Estimate how much it might cost to manufacture your product.

If you sold your product for cost price plus 40% how much profit could you make selling to your school?

Next stepsRemember there are more resources at networking.stemnet.org.uk

For more on STEM Clubs visit www.stemclubs.net

To speak with your local STEMNET representative visit www.stemnet.org.uk/regions

CREST Awards are easy-to-run, encourage students to continue with STEM subjects, and add real value to UCAS applications. To link this activity’s extra ideas to a CREST Bronze Award, contact your CREST Local Coordinator: www.britishscienceassociation.org/crestcontacts

Accredited Scheme