Sensor Review, Volume 35, Issue 1, January 2015.
Purpose One of the key components of the micro-sensors is MEMS micro-hotplate. In this paper, a platinum micro-hotplate with the proper geometry using the analytical model based on the heat transfer analysis is introduced to improve both heating efficiency and time constant. Design/methodology/approach This analytical model exhibits that suitable design for the micro-hotplate can be obtained by the appropriate selection of square heater (LH) and tether width (WTe). Based on this model and requirements of routine sample loading, the size of LH and WTe are chosen 200 µm and 15 µm respectively. In addition, a simple micro-fabrication process is adopted to form the suspended micro-heater using bulk micromachining technology. Findings The experimental results show that the heating efficiency, heating and cooling time constants are 21.27 K/mW, 2.5 ms and 2.1 ms respectively for the temperature variation from 300 K to 400 K in the fabricated micro-hotplates which are in closed agreement with the results obtained from the analytical model with errors within 5%. Originality/value Our design based on the analytical model achieves a combination of fast time constant and high heating efficiency that are comparable or superior to the previously published platinum micro-hotplate.
Purpose One of the key components of the micro-sensors is MEMS micro-hotplate. In this paper, a platinum micro-hotplate with the proper geometry using the analytical model based on the heat transfer analysis is introduced to improve both heating efficiency and time constant. Design/methodology/approach This analytical model exhibits that suitable design for the micro-hotplate can be obtained by the appropriate selection of square heater (LH) and tether width (WTe). Based on this model and requirements of routine sample loading, the size of LH and WTe are chosen 200 µm and 15 µm respectively. In addition, a simple micro-fabrication process is adopted to form the suspended micro-heater using bulk micromachining technology. Findings The experimental results show that the heating efficiency, heating and cooling time constants are 21.27 K/mW, 2.5 ms and 2.1 ms respectively for the temperature variation from 300 K to 400 K in the fabricated micro-hotplates which are in closed agreement with the results obtained from the analytical model with errors within 5%. Originality/value Our design based on the analytical model achieves a combination of fast time constant and high heating efficiency that are comparable or superior to the previously published platinum micro-hotplate.