Figure 6: Simple demonstrations of the as-prepared TE modules.

(a–c) A large voltage difference of ∼3 mV was rapidly created when fingers pinch the one end of the module. (d–f) A large voltage difference of ∼4.5 mV was rapidly created when the water of 40 °C were poured into the beaker till the liquid level reached the lower edge of the module. The room temperature is ∼27 °C.