Liquid crystals have become very common in the last 20 years as displays for electronic devices ("LCD" stands for "Liquid Crystal Display"). Liquid crystals are a fourth state of matter; they have greater ordering than more normal liquids but less ordering than crystalline solids. All phase changes have a characteristic phase transition temperature for a given set of conditions; liquid crystals have separate transition temperatures where they change into "normal" liquids (melt) and into "normal" solids (solidify).
In this activity, participants are invited to interact with liquid crystal thermal sheets. The temperature-sensing properties of liquid crystals are described in terms of their structure and phase.
- Liquid Crystal Sensors activity guide
- Liquid crystal thermal sheets for three different temperature ranges
- Heating pad