This is just a simple example of thermocouple:

In this figure, A and B are two different metal. When the temperature is different between 1 and 2, there will appear electric current. www.zhangpeng.info

Now we offten use sheathed thermocouple in industry field. These thermocouples is just put two kinds of metal in one pipe.

Zhangpeng have a idea to make new type of thermocouple. We just use the pipe to act as one metal and put the other metal in it then fill out the gap with MgO to insulate. If this idea come true, the thermocouple can be smaller.

This is my idea to make new type of themocouple. There are some problems. I think how to make it stable and live long it most important.