A Novel Forked-Finger Electrode-Structured Thermoelectric Module with High Output Power

Abstract

Thermoelectric harvesting technology is a clean and friendly energy-conversion technology. In the π-type traditional thermoelectric module (TEM), n- and p-type thermoelectric legs are electrically connected in a series to generate large temperature differences in the heat flow direction and to achieve a better module performance. However, damages to one thermoelectric leg could lead to the failure of the thermoelectric system. This work proposes a novel forked-finger electrode-structured thermoelectric module (FFTEM), which enables a simultaneous parallel electrical connection and thermal transfer in a homogeneous material’s thermoelectric leg set. The four thermoelectric legs share a common pair of electrodes, and this parallel structure makes the FFTEM benefit from low internal resistance, a high operating current, and high output power. The internal resistance and output power of the TEM are 4.25 mΩ and 1.766 mW, respectively, at a temperature difference of 40 °C. The internal resistance of the FFTEM is reduced to 0.81 mΩ, and the output power is increased to 13.81 mW. The FFTEM’s maximum output power achieved under temperature-dependent conditions is nine times that of the TEM’s output power. This FFTEM design provides a configuration to obtain a much higher output power, which could benefit future applications of thermoelectric devices.

Keywords

• thermoelectric generator
• forked-finger electrode structure
• high output power
• transient output characteristics
• thermal contact resistance