Thermochromic Coasters
custom heat reactive coasters using thermochromic dyes

MIT Museum
Collaborator: Yael Saiger

Thermochromism

The deliberate use and understanding of thermochromic materials in a scientific context developed prominently in the 20th century. In the mid-20th century, researchers began to investigate and develop thermochromic materials for practical applications, such as temperature indicators and sensors. Liquid crystal thermometers and displays became commercially available in the latter half of the 20th century, showcasing the controlled use of thermochromic properties.

Liquid crystals exhibit alterations in molecular arrangement in response to temperature variations, leading to changes in their optical properties and perceived color through the change in structural colors. Structural thermochromism is characterized by modifications in the physical arrangement of a material, influencing its interaction with light. This can occur through changes in crystal lattice, molecular organization, or orientation, ultimately causing shifts in color perception. This phenomenon is widely applied in technologies such as liquid crystal thermometers, mood rings, and smart windows.

Leuco Dyes

Similarly, thermochromism using leuco dyes involves reversible color changes in response to temperature fluctuations. Leuco dyes, in their colorless state, become transparent but transition to a colored form upon exposure to heat due to a reversible change in pH-levels. Widely applied in inks, coatings, and textiles, these materials find use in products like temperature-sensitive labels and mood-changing fabrics, offering dynamic and interactive visual effects.