Liquid Crystal Thermometers
Using liquid crystal thermometers in the classroom.Copyright 2019 Amanda Lengnick-Hall, University of Texas RET
Students become engineers as they create thermometers that can be used to monitor temperatures in reptile terrariums. By using liquid crystals, students learn about the characteristics of materials and wavelengths of light emissions. Students then apply this knowledge to make a liquid crystal thermometer and test it at various temperatures. Students then iterate their thermometer designs by using different mixtures of the liquid crystal formula to optimize the temperature range for their project’s environmental needs.
Students directly observe color changes that indicate changes at the nanoscale level. These observations relate to work engineers are doing with silicon nanocrystals: using the wavelength of the light emissions as an indicator of the size of the crystal. The liquid crystal allows engineers to observe changes due to changes in size, which is due to the helix structure of the crystals being stretched and compacted. Making these observations allows engineers to iterate and design better products that use unique substances.
After this activity, students should be able to:
- Explain how liquid crystals can indicate temperature change.
- Calculate approximate temperature based on the color expressed by the liquid crystals.
- Define the difference between macro and nano scales.