Core temperature sensor with thermal conductivity compensation

In one embodiment, a temperature sensor system includes a sensor assembly with a temperature sensing portion configured to generate a first signal based upon a temperature of body proximate a surface portion of the temperature sensing portion, and a thermoelectric generator portion configured to receive heat flow from the body through the temperature sensing portion and to generate a second signal based upon the heat flow. A control unit is operably connected to the sensor assembly and a memory and configured to execute program instructions stored in the memory to calculate and output a corrected temperature based upon the first signal, the second signal, and at least one correction factor stored in the memory. The at least one correcting factor is determined based upon at least one of a thermal conductivity of the sensor assembly, a size of the sensor assembly, and an aspect ratio of the sensor assembly.