Relative-Air Humidity Sensing Element Based on Heat Transfer of a Single Micromachined Floating Polysilicon Resistor

Authors

  • Paulo Zambrozi Jr.
  • Fabiano Fruett

DOI:

https://doi.org/10.29292/jics.v7i2.365

Keywords:

Heat transfer mechanisms, air-humidity sensor, thermal conduction, thermal convection

Abstract

An air-humidity sensing element based on heat transfer mechanisms (conduction and convection) is presented. The sensing element is a single floating resistor of doped polysilicon, which operates in two phases: thermal actuation and thermal sensing. As thermal actuation, a convenient biasing current is applied to the resistor leading its self-heating by Joule Effect. As thermal sensing, the resistor biasing current is reduced and its Thermal Time Constant (τ) during the cool-down process is measured. Characterization results show that τ is closely related to the air relative humidity (%RH). This sensor presents a maximum power consumption of 5 mW.

Additional Files

Published

2020-12-27