Optimization and fabrication of a dual thermopile sensor based on the BEM

Abstract A thermopile sensor containing a dual black-body system for the compensation of significant environmental temperature change has been developed. The boundary-element method (BEM) and genetic algorithm (GA) have been adopted for analysis and optimization of the sensor. The object function of optimization is mainly focused on sensitivity. The present dual sensor is composed of one radiation filter, one diaphragm and two radiation absorption areas. One receiving area senses the radiation energy from the object and the other area compensates the environmental temperature variation. A reflection mirror focuses on the sensing area and the compensation area can exchange radiation energy with the environmental atmosphere. The analytical solution is compared with the BEM solution in simple sensor geometry. It is found that modelling the sensor is easier with the BEM than with the finite-element method (FEM). In addition, the present BEM modelling provides a more realistic solution than the previously presented analytical solution. The fabricated dual thermopile sensor shows good agreement with the simulated result using the BEM.