Thermal conduction from microcantilever heaters in partial vacuum

Abstract

This paper reports the thermal and electrical characteristics of a heated microcantilever in air and helium over a wide range of pressures. The cantilever heater size modulates thermal conductance between the cantilever and its gaseous surroundings; and the Knudsen number, Kn characterizes this thermal conductance. When Kn<1, thermal transport from the cantilever heater depends on gas pressure, and when Kn>1, thermal transport from the cantilever heater remains constant. This measurement of thermal conductance around Kn = 1 could aid the design and analysis of Pirani sensors and other microscale thermal sensors and actuators.