Development of a Flexible Surface Wetness Sensor Using RFID Technique

• Main Authors: Bo-Yan Wang, 王柏諺
• Other Authors: Ping-Hei Chen
• Format: Others
• Language: en_US
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/03345919328025149984

碩士 === 國立臺灣大學 === 機械工程學研究所 === 94 === The present study develops a flexible sensor for detecting surface wetness and the sensor transmits the information of RF signal based on RFID technique. The operation frequency of the RFID system is at 13.56MHz. The MEMS process was employed to fabricate the antenna and the sensor of RFID tag on FPCB. The shape of the RFID tag’s antenna is designed as octangle that surrounds a comb shape sensor. The transmitting information of the RFIC is changed as the surface condition of sensor changed from dry to wet and it can be observed on the screen of the digital oscilloscope. The simulations of the equivalent circuits of the RFID tag and of the S-parameter are also obtained in this study. The simulation results show the operation voltage of the RFIC, the quality factor (Q-factor) and the resonant frequency of the RFID system. The RFID tag’s antenna has an outer diameter of 2.7 cm and the quality factor of the RFID tag has a value of 10.05. The tag and the reader of RFID system are communicated through inductive coupling and the maximum transmitting range of the RF signal is about 15 cm