Abstract
Thermochromic liquid crystals have been exploited in novelties and in high-technology applications alike since the earliest years of liquid crystal technology. They have also played a central role in the elucidation of the structures of liquid crystal phases and their inter-relationship, the optics of mesophases, the nature of phase transitions and their static and dynamic continuum theory. Despite this long history, many of the materials and applications have been continually exploited for several decades, indicating an early achievement of maturity in this area of liquid crystal technology. This article briefly reviews the main materials, applications and devices, and attempts to place them in the context of related developments in liquid crystal science.