Two slice pop-up toaster

Food preparation and cooking are important tasks in most families. Kitchen appliances are available to assist with these jobs.

hand tools

  • egg beater

electrical appliances

  • electric kettle
  • pop-up toaster
  • mixer
  • electric skillet
  • blender, food processor
  • microwave oven
  • bread maker – the kneader uses fluid dynamics, how the dough moves when the paddle turns.

What’s the problem?
The toaster is a daily part of breakfast (and lunch and maybe even dinner). The toaster toasts the bread.

  • Ask – How do all of the different settings work? How does the toaster know when to pop the toast up?
  • Imagine – Making toast crispy on both sides is the main job of the toaster. How can both sides be cooked at the same time? How does the cooking stop when the toast is “done”? How can you pick up the toast without touching the cooking element?
  • Design, Build – A toaster uses infrared radiation to heat a piece of bread. A spring-loaded tray pops the toast out. This keeps you from having to turn the toaster upside down.
  • Improve – A timer turns the toaster off automatically and at the same time releases the tray so the toast pops up.

That’s engineering

  • Infrared (IR) radiation – a type of electromagnetic radiation (a wave with electricity) . The wave is longer than light which humans can see and shorter than microwaves. The word infrared means below red. It comes from the Latin word infra (meaning below) and the English word red. (Infrared light has a frequency below the frequency of red light.) The infrared wave is between 750 nm and 1 mm. People sense infrared as heat.

Engineering ideas

  • fluid dynamics, paddles, vortex, infrared radiation, spring, heat, electromagnetic, wave, electricity, microwaves, frequency, heat