Fabrication of wooden thermoelectric legs to construct a generator

Herein, wooden-stick-based thermoelectric legs are introduced as a new type of thermoelectric legs. As a proof of concept, graphite- and bismuth-coated wooden sticks are fabricated with a green method, and their use as thermoelectric elements is successfully demonstrated by constructing a test thermoelectric generator. The generator based on 20 pairs of p–n legs shows a maximum power output of ∼18 nW on heating one side of the device to 70°C. The strategy can suitably be extended to other good thermoelectric materials. The approach can be promising due to the ultralow thermal conductivity of the wooden substrate pillars in contrast to other typical substrates such as glass, and hence, better thermal gradients across the device can be achieved. These environmentally friendly, non-toxic and low-cost wooden-stick-based thermoelectric devices with good thermoelectric material coatings can be conveniently used for low-grade industrial waste heat conversion applications.