Heat sensitive sheets

Use liquid crystal heat sensitive sheets outdoors on a sunny day.
Science content
Physics: Heat (3)
Lessons activity is in
  • liquid crystal heat-sensitive sheets (I get Edmund Optics 25-30 range and cut into 9 smaller squares, before laminating. Note: expensive)
  • sun
  • walls, playground equipment, other outdoor objects, some that get warm in the sun
  • tub of water

Distribute sheets to students.
Allow them to discover that the sun changes the colour of the sheets.
Give them the colour scale (for my sheets, coolest is black, then getting warmer is red, orange, yellow, blue, then black again, so black can either be coolest or warmest).
Allow students to explore the environment with their sheet.
If they need suggestions, see the photos:
block the sun's radiation with your hand/playground structure to make an image on the sheet
use the sheet to measure how warm different playground structures are
use the sheet to measure relative heat given off by differently-coloured walls
use a heat pad to change the colour of the sheet
use a tub of water to cool the sheet
use drips of water to make patterns and paint on the sheet

Discuss what kinds of heat transfer heated the sheets up:
Radiation from the sun.
Conduction when the sheet is pressed against a surface or water draws heat from the sheet.

Grades taught
Gr 2
Gr 3
Teaching site
McBride Elementary