Resistance-type Humidity Sensor Using CNTs Sensing Material with Al2O3 Conformal Coating for Enhanced Sensitivity
- Resource Type
- Conference
- Authors
- Hung, Chien-Ya; Sung, Wei-Lun; Chen, Sih-Chieh; Fang, Weileun
- Source
- 2019 20th International Conference on Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII) Solid-State Sensors, Actuators and Microsystems & Eurosensors XXXIII (TRANSDUCERS & EUROSENSORS XXXIII), 2019 20th International Conference on. :761-764 Jun, 2019
- Subject
- Bioengineering
Components, Circuits, Devices and Systems
Fields, Waves and Electromagnetics
Photonics and Electrooptics
Power, Energy and Industry Applications
Robotics and Control Systems
Sensors
Humidity
Aluminum oxide
Sensitivity
Coatings
Moisture
Surface treatment
Humidity sensor
CNTs
CNTs/Al2O3 composite
ALD process
- Language
- ISSN
- 2167-0021
This study presents a resistance-type humidity sensor using carbon nanotubes (CNTs) with Al 2 O 3 coating. CNTs are typical materials for gas sensing and have the property resistance changing when absorbing moisture. Al 2 O 3 is an excellent material for moisture absorption. Thus, this study uses the serpentine CNTs design integrated with Al 2 O 3 conformal coating by Atom Layer Deposition (ALD) process to form a CNTs/Al 2 O 3 composite for enhanced sensitivity of a humidity sensor. Features of this approach: (1) ALD Al 2 O 3 to penetrate CNTs cluster and conformally coat on each CNTs surface; (2) High surface-to-volume ratio sensing structure offered by CNTs; (3) High moisture absorption capability offered by Al 2 O 3 coating. Measurement results show that the sensitivity of the humidity sensors with 300°C annealed CNTs/Al 2 O 3 composite is ~7-folds higher than that of bare-CNTs.