Through simulation and analysis of steady-state and transient thermal performance of the MEMS gas sensor micro-hotplate

it is found that when the steady-state heating voltage ranges from 1.4 to 2.0V

the temperature uniformity of the micro-hotplate can reach 12% to 13%.When the high-level duration of the transient heating voltage exceeds 40ms

the temperature of the micro-hotplate can reach the corresponding steady-state temperature.When the low-level duration exceeds 10ms

the temperature of the micro-hotplate dro

ps rapidly

making the gas-sensing material deviate from the optimal operating temperature.MEMS devices with sensitive film thickness uniformity less than 1μm are fabricated by using In

2

O

3

sensitive material derived from metal-organic framework(MOF).Their gas-sensing performance is tested.When the heating voltage is 1.8V

sensitivity of the sensor to NO

2

concentration of 100×10

-9

is greater than 6

and the response and recovery times are approximately 30s and 20s

respectively.When the concentration of NO

2

is less than 2×10

-6

the relationship between sensitivity and concentration is fitted using a power function with the coefficient of determination (

R

2

) of 0.995.When simultaneously meeting low power consumption and a sensitivity greater than 5

with a pulse width modulation (PWM) cycle of 1080s

the equivalent power consumption is less than 1mW.