Thermopile power measurement for heat balance calorimetry

Very high resolution power sensors are required for measuring the rate of heat production (~10 μW) of small samples of heart muscle (rat cardiac trabeculae, ~2 mm long and ~200 μm diameter). In this paper, we examine the design criteria for thermopiles to maximize their signal-to-noise ratio for heat balance calorimetry. We found that those thermopiles with a high thermoelectric figure-of-merit (ZT) are the best for power measurements. An initial prototype with a resolution of 53 nW has been built.