A NOVEL MICRO-PELLISTOR BASED ON NANOPOROUS ALUMINA BEAM SUPPORT

The traditional design of the catalytic combustion gas sensor in Micro ElectroMechanical Systems (MEMS) micro-hotplate employs a Pt resistive track as the micro-heater. The realized structure and fabrication are the key elements of the micro-hotplate. Directly fabrication of micro-pellsitor catalyst is very difficult because of the small dimensions of the active area. In this paper, a novel micro-pellistor was designed by combining micro fabrication technique and nano technology. The supporting beams and micro-hotplate of the micro-pellistor were made of nonoporous alumina film. The active area of the designed and fabricated micro-pellistors ranges from 200×200 μm2 to 450×300 μm2. The micro- pellistor was heated by platinum thin film heater and the Pd catalyst was deposited by dipping the PdCl2 solution on the detecting element. The lowest power consumption is 50 mW at 500 °C and the maximum temperature can reach 900 °C before rupture. The response of the devices to methane is also tested. The new design provides a new way to fabricate micro-pellistor.

The traditional design of the catalytic combustion gas sensor in Micro ElectroMechanical Systems （MEMS） micro-hotplate employs a Pt resistive track as the micro-heater. The realized structure and fabrication are the key elements of the micro-hotplate. Directly fabrication of micro-pellsitor catalyst is very difficult because of the small dimensions of the active area. In this paper, a novel micro-pellistor was designed by combining micro fabrication technique and nano technology. The supporting beams and micro-hotplate of the micro-pellistor were made of nonoporous alumina film. The active area of the designed and fabricated micro-pellistors ranges from 200× 200μm2 to 450 ×300μm2. The micro- pellistor was heated by platinum thin film heater and the Pd catalyst was deposited by dipping the PdC12 solution on the detecting element. The lowest power consumption is 50 mW at 500℃ and the maximum temperature can reach 900℃ before rupture. The response of the devices to methane is also tested. The new design provides a new way to fabricate micro-pellistor.