Heat Sensors

After a discussion with Tony in preparation for a talk with Pete regarding ideas for projects I briefly looked at heat sensitive surfaces and sensors. 

I was thinking I could use a heat sensor in my project - so when a cigarette is stubbed out on a potential plate at the top of a butt bin, the heat would be detected by the sensor which would then triggered/activate a driver motor.

I looked at thermochromism - the ability of substance to change color due to a change in temperature.
Thermochromic coating could be used to wrap the plate; when the cigarette is stubbed out the coating becomes transparent as it’s heated, it reveals a potential design beneath.
Because both the coating is black and the design background is black in the process, it gives the impression that the design is appearing, rather than the coating disappearing.
Colour and movement would be the attraction in my project in this case.

Contact heat Sensors thermocouples sensors is in the group of contact heat sensors, other sensors in this group includes Resistance – RTDs & PRTs & SPRTs, Thermistors, Labels & Crayons & Paints (Phase Change Devices), Glass Thermometers (LIG), Filled Systems Thermometers, Bimetallic Thermometers (Bimetal), Semiconductor Thermometers (Integrated Circuits or ICs & Diodes), Liquid Crystal, Thermowells.

Non Contact Heat Sensor Is the other group most commercial and scientific noncontact temperature sensors measure the thermal radiant power of the Infrared or Optical radiation that they receive from a known or calculated area on its surface, or a known or calculated volume within it.