Here is a simple way of demonstrating seeback effect using common electronics lab materials:
- Cut out a square piece of single sided copper clad board
- Make vertical groves in it thereby separating the copper into isolated strips
- Take pieces of solder wire and solder each piece of solder wire on the non copper clad side of the PCB between the ends of two successive copper strip. (Look at the "Thermopile" Schematic here)
If the solder wire you have are thin, you can twist two lengths together to increase the effective thickness like I have done.
- Dunk one end into pure ice cold water and heat the other end and observe the voltage across the ends of the circuit using a multimeter.