Design and analysis of dual working area micro-hotplate based on thermal crosstalk

Abstract

Micro-hotplates have provided the possibilities of miniaturization, low power consumption, and high integration for widespread application in MEMS sensors, such as the MEMS-based metal oxide gas sensors. However, thermal crosstalk among micro-heating areas has greatly restricted the design of a micro-hotplate. Although the issue of thermal crosstalk is annoying between independent working areas, it can reduce power consumption to a certain extent. This paper proposed a dual working area micro-hotplate based on thermal crosstalk through the foundation of an electro-thermal analysis model. It especially proposes a strategy of introducing optimized parameters from a single working area to a dual working area. Besides, evaluation for thermal crosstalk was achieved by setting the temperature of one working area as constant and monitoring the power of the other working area when it reaches a certain temperature. The results indicated that the designed dual working area micro-hotplate can save at least a quarter of the heating power compared with the single working area micro-hotplate at the same working temperature of 300 \(^\circ \textrm{C}\) and other same parameter settings. Within the acceptable limits of mechanical deformation, the heating efficiency of the micro-hotplate is improved from 4.10 mW/(mm\(^2\).\(^\circ \textrm{C}\)) to 2.99 mW/(mm\(^2\) \(^\circ \textrm{C}\)). It was demonstrated that the introduction of thermal crosstalk can significantly reduce the power consumption of the micro-hotplate, providing a viable solution for enhancing the properties of MOX gas sensor array.