Remote Thermal Sensing by Integration of Corner-Cube Optics and Thermochromic Materials

Thermochromic materials (TCMs) change their color in response to temperature variations. Here, presented is a rare combination of TCMs with conventional corner-cube retroreflectors (CCRs) that are widely used in industry for their ability to return an incident beam of light directly back toward its source. The TCM quoted CCR (TCR sensor) allows remote measurements of the quantitative thermal information of the environment to which the TCR sensor is subjected. Two different commercially available thermochromic systems, a leuco dye and liquid crystals, are utilized as sensing materials. Since the incident (probe) beam and reflected (sensing) beam always follow the opposite directions 180°, this allows the probing and sensing to be carried out remotely from the same spot. Therefore, such remote sensing mechanism is virtually independent of the incident and detection beam angles. The TCR sensor has potential application in the space research, mining, power generation facilities, radioactive environments, and other industries where remote temperature sensing is a stringent requirement.