| 1. |
- Feng, Yi, et al.
(författare)
-
Flexible UHF resistive humidity sensors based on carbon nanotubes
- 2012
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 12:9, s. 2844-2850
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents the investigation of the resistive humidity-sensing properties of multi-walled carbon nanotubes (MWCNTs). MWCNTs functionalized by acid treatment (f-MWCNTs) exhibit rather high sensitivity in resistance toward humidity, owing to the presence of carboxylic groups on the nanotube surface. By integrating the f-MWCNTs resistor into a wireless sensor platform, flexible humidity sensors for ultra-high frequency applications are investigated. The operating frequency range of the sensor is dramatically increased from 600 MHz to 2 GHz by adjusting the resistor-electrodes' configuration. This enhancement is predominately attributed to the variation in parasitic capacitance between the resistor-electrodes.
|
|
| 2. |
- Feng, Yi, et al.
(författare)
-
Low Cost Printed Chipless RFID Humidity Sensor Tag for Intelligent Packaging
- 2015
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 15:6, s. 3201-3208
-
Tidskriftsartikel (refereegranskat)abstract
- This paper presents a fully-printed chipless radio frequency identification sensor tag for short-range item identification and humidity monitoring applications. The tag consists of two planar inductor-capacitor resonators operating wirelessly through inductive coupling. One resonator is used to encode ID data based on frequency spectrum signature, and another one works as a humidity sensor, utilizing a paper substrate as a sensing material. The sensing performances of three paper substrates, including commercial packaging paper, are investigated. The use of paper provides excellent sensitivity and reasonable response time to humidity. The cheap and robust packaging paper, particularly, exhibits the largest sensitivity over the relative humidity range from 20% to 70%, which offers the possibility of directly printing the sensor tag on traditional packages to make the package intelligent at ultralow cost.
|
|
| 3. |
- Xie, Li, et al.
(författare)
-
Integration of f-MWCNT Sensor and Printed Circuits on Paper Substrate
- 2013
-
Ingår i: IEEE Sensors Journal. - 1530-437X .- 1558-1748. ; 13:10, s. 3948-3956
-
Tidskriftsartikel (refereegranskat)abstract
- The integration of sensors endows the packages with intelligence and interactivity. This paper is considered the most suitable substrate of smart packages because it is cost-effective, light, flexible, and recyclable. However, common concern exists regarding the reliability of paper-based system against bending and folding. In this paper, inkjet-printing of silver nanoparticles is used to form circuit pattern as well as interconnections for system integration on paper substrate. A humidity sensor made by functionalized multiwalled carbon nanotubes is fabricated on the same substrate. We evaluate the electrical performance of paper electronics and the reliability against bending and folding. The results reveal the capability and the limitation of paper electronics in terms of flexibility. The concept of a paper-based smart electronic system and the manufacture process are demonstrated by an interactive humidity sensor card prototype.
|
|
