A high heating efficiency two-beam microhotplate for catalytic gas sensors

This paper presents a suspended-membrane-type microhotplate with high heating efficiency for catalytic gas sensors. This microhotplate has only two supporting beams through which heat loss via conduction can be effectively reduced. By isolating heat in a rectangular active membrane, high heating efficiency can be achieved. Power per active area (PPAA) of the microhotplate is only about 30% in comparison with current microhotplates. Based on the two-beam microhotplate, a catalytic gas sensor was fabricated by sol-gel process introducing Pd-Pt as the catalytic material. Test results indicate that this catalytic gas is sensitive to methane with a high sensitivity. And the sensor output has a fairly linear relation to methane concentration.