The current theory of thermoelectric generators can only deal with situations where a thermoelectric generator operates under a constant temperature difference. In this paper, a new theoretical formulation is reported that can be applied to situations where a thermoelectric generator operates under constant heat flux, completing the thermoelectric generator theory that has been absent for more than half a century. Central to the development of this new theory is a thermoelectric relationship that links the temperature difference across a thermoelectric generator in an open circuit to that in a closed circuit, enabling new formulation. This new theory offers the capacity to calculate the maximum power output and maximum conversion efficiency of a thermoelectric generator that operates under a constant heat flux, which represents the typical characteristics of the majority of heat sources and is anticipated to have a significant impact on the design and optimization of many practical thermoelectric generators. Moreover, the theory lays the foundation for a deep understanding of the unique characteristics of thermoelectric I–V curves and opens up a new way to investigate and evaluate the thermoelectric properties and performances using the I–V curves. Other foreseeable outcomes due to this new theory include the development of a novel thermoelectric characterisation technique based on thermoelectric I–V curves, a variable thermal resistance for heat regulation and exploring the possibility of improving the performance of thermoelectric generators by pulse mode operation.

A novel Hg²⁺-responsive thermometer system for translating mercury detection into temperature monitoring was developed based on an aggregation-activated oxidase-like activity of gold nanoparticles.

A recent theoretical study proposes a new way to evaluate thermoelectric devices by measuring two I–V curves—one obtained under a constant temperature difference and the other obtained for a constant thermal input. We report an experimental demonstration of the feasibility of this novel technique. A measurement system was designed and constructed, which enables both types of I–V curves to be obtained automatically. The effective ZT values of a thermoelectric module were determined using this system and compared with those measured by an impedance spectroscopy technique. The results confirm the validity of the proposed technique. In addition, the capability of measuring ZT under a large temperature difference was also investigated. The results show that the ZTs obtained for a large temperature difference are significantly smaller than those for a small temperature difference, providing insights into the design and operation of thermoelectric modules in realistic applications.