Title :
Polymer-electrolyte-film-based humidity sensor with integrated signal conditioner
Author :
Manzan, D. ; Nogueira, Viviane ; de Paoli, Marco Aurelio ; Filho, Carlos Alberto dos Reis
Author_Institution :
Electr. Eng. Sch., State Univ. of Campinas - UNICAMP, Campinas
Abstract :
This paper describes a humidity sensor, whose sensing element is an ionic polymer film the resistance of which is measured by a dedicated signal conditioning circuit implemented in 0.35 um CMOS. In addition to providing excitation and measurement of the film resistance, the implemented signal conditioning circuit detects the temperature of the sensing film by way of an on-chip temperature sensor in order to perform the necessary compensation for the influence of the temperature upon the measured relative humidity. The sensing polymer film is 10.4 mum thick deposited on glass by casting using a solution of P(EO-EPI)84-16+NaI on top of the interdigitated gold electrodes. The signal conditioning circuit excites the sensing element with a 50% duty-cycle, 1 KHz, 700 nA, square wave. Samples of the sensor have been measured in the range 25 to 85% RH, varying the temperature from 10 to 50degC. At 55%RH/30degC the mean value of resistance per square of the measured samples is 16.9 k Omega/sqsubsqsup.
Keywords :
CMOS integrated circuits; humidity measurement; humidity sensors; polymer electrolytes; polymer films; signal processing equipment; temperature sensors; CMOS; film resistance; integrated signal conditioner; interdigitated gold electrodes; ionic polymer film; on-chip temperature sensor; polymer-electrolyte-film-based humidity sensor; relative humidity; signal conditioning circuit; Electrical resistance measurement; Glass; Humidity measurement; Integrated circuit measurements; Performance evaluation; Polymer films; Sensor phenomena and characterization; Signal detection; Temperature measurement; Temperature sensors;
Conference_Titel :
Electronics, Circuits and Systems, 2005. ICECS 2005. 12th IEEE International Conference on
Conference_Location :
Gammarth
Print_ISBN :
978-9972-61-100-1
Electronic_ISBN :
978-9972-61-100-1
DOI :
10.1109/ICECS.2005.4633609
