A flexible surface wetness sensor using a RFID technique.
This paper presents a flexible wetness sensor whose detection signal, converted to a binary code, is transmitted through radio-frequency (RF) waves from a radio-frequency identification integrated circuit (RFID IC) to a remote reader. The flexible sensor, with a fixed operating frequency of 13.56 MHz, contains a RFID IC and a sensor circuit that is fabricated on a flexible printed circuit board (FPCB) using a Micro-Electro-Mechanical-System (MEMS) process. The sensor circuit contains a comb-shaped sensing area surrounded by an octagonal antenna with a width of 2.7 cm. The binary code transmitted from the RFIC to the reader changes if the surface conditions of the detector surface changes from dry to wet. This variation in the binary code can be observed on a digital oscilloscope connected to the reader.
Department of Mechanical Engineering, National Taiwan University, No. 1, Roosevelt Rd Sec. 4, Taipei 10617, Taiwan. taopdso@yahoo.com.tw
Cheng-Hao
CH
Yang
Jui-Hung
JH
Chien
Bo-Yan
BY
Wang
Ping-Hei
PH
Chen
Da-Sheng
DS
Lee
D015374:Biosensing Techniques / Q000379:methods*; D009991:Oscillometry; D011846:Radio Waves; D013499:Surface Properties; D014867:Water
D014867:Water