Thermal matching of a thermoelectric energy harvester with the environment and its application in wearable self-powered wireless medical sensors

In this work, we discuss why classical thermoelectric theory is not enough to design an optimized energy harvester. Then, the general conditions are defined, which are required to make a thermoelectric converter effective in such application. The necessity of the work has been prompted by the fact that while modeling the harvesters neither the constant temperature difference, nor the heat flow cannot be assumed. We show that simple equations obtained using electro-thermal analogy allow optimization of energy harvesters to reach their top performance characteristics. Thermal matching in MEMS thermopiles is discussed then. The examples of application thermally matched thermopiles for powering state-of-the-art wearable wireless sensors are discussed in the end.