A New Way to Read the Road
To make the colors change on pavement, a special varnish is applied. The varnish is made of a polymer containing a thermochromic pigment. The same kind of technique is applied to pool thermometers and the packages on frozen vegetables. At around 1 degree Celsius, the pigment on the pavement turns bright pink. When the temperature rises above 2 derees Celsius, the color with vanish.
"The beauty of the system," according to project leader Thomas Devanne, "is that information would be available in real time, allowing roads to be salted exactly where and when needed, or cautioning drivers to take extra care as roads start to become dangerous." The system can also be used pretty much anywhere that gets cold. It can also be used on sidewalks and driveways.
The real test will come when, during the summer months, Ultraviolet Radiation will be at a maximum. The varnish will need to be able to withstand the extreme heat and heavy traffic loads without losing its color-changing ability. So next time your driving during the winter months, keep an eye on the road and you just might see some pink under the ice.
From : NewScientistTech