Thermal behavior of a novel micro-fuel cell-based methanol concentration sensor

Methanol concentration sensors are a key component in the development of direct methanol fuel cells. This paper describes a novel micro-fuel cell based methanol sensor, in which a methanol solution’s energy content is converted into thermal and electrical energy. A zero-dimensional mathematical model is provided to predict the thermal behavior of the sensor. This model reveals a linear correlation between the sensor’s maximum temperature rise and its heat production rate. The sensor’s thermal behavior was investigated experimentally under three different operation modes: (1) constant resistance, (2) constant current, and (3) constant voltage. The experimental results showed that the sensor’s maximum temperature rise had a linear relationship with methanol concentrations up to 10 mol/L. These results also confirmed the assumption of the mathematical model, namely that the heat production rate of the sensor is a linear function of methanol concentration. Therefore, the maximum temperature rise can be used as an indicator of methanol concentration.