Lämpövärit

Lämpövärit, often translated as thermochromic materials or heat-sensitive colors, are substances that change color in response to temperature fluctuations. This phenomenon is a result of reversible chemical or physical changes within the material's structure. When heated to a specific activation temperature, the molecules rearrange themselves, altering how they absorb and reflect light, thus producing a new color. Upon cooling, they revert to their original state and color.

The most common type of lämpövärit are liquid crystals and leuco dyes. Liquid crystals change color by altering their molecular alignment with temperature, creating a spectrum of colors like red, green, and blue. Leuco dyes involve a reversible chemical reaction where a colorless form reacts with an acidic component to become colored, and this reaction is reversed by heat.

Lämpövärit have a wide range of applications. They are found in novelty items like mood rings and color-changing mugs, but also in practical uses such as battery testers, medical thermometers, food packaging to indicate freshness or safe temperatures, and in smart windows that adjust their tint based on sunlight. The temperature at which the color change occurs can be precisely controlled during manufacturing, allowing for customization for specific needs. The reversibility of the color change makes them reusable and often environmentally friendly.