Sensistor is a resistor whose resistance changes with temperature.
![Thumb](http://upload.wikimedia.org/wikipedia/commons/thumb/4/48/Sensistor_by_Zureks.svg/220px-Sensistor_by_Zureks.svg.png)
The resistance increases exponentially with temperature,[1] that is the temperature coefficient is positive (e.g. 0.7% per degree Celsius).[2]
Sensistors are used in electronic circuits for compensation of temperature influence or as sensors of temperature for other circuits.[3]
Sensistors are made by using very heavily doped semiconductors so that their operation is similar to PTC-type thermistors. However, very heavily doped semiconductor behaves more like a metal[4] and the resistance change is more gradual than it is the case for other PTC thermistors.