Abstract
In this study an investigation has been made on the electrical properties of Organic Humidity Sensors being fabricated by the use of cellulose and poly-N-epoxypropylcarbazole (PEPC). The 2 wt% of cellulose and 4 wt% of PEPC were blended in Benzol. In the fabrication of Cu/Cellulose/PEPC/Cu sensor, a composite thin film was deposited on copper electrodes by drop casting. The electrodes were deposited by sputtering process in which the gap between the electrodes was kept as 45 μm. The capacitance and dissipation of the sensors were measured under the effect of relative humidity. It was found that the capacitance and dissipation of the sensor increased 21 and 81 times respectively with increase of the Relative Humidity (RH) ranging from 45%-89%. By measured capacitance and dissipation, the resistance and impedance were calculated. The capacitance and resistance-humidity relationships showed significant change in the range of 67%-89% RH and 45%-83% RH respectively. The impedance-humidity relationship demonstrated more uniform changes in the range of 45%-89% RH relative to the capacitance and resistance-humidity relationships. Humidity dependent properties of the sensor make it attractive to be used in capacitive, resistive and impedance type humidity sensors, thus it can be used in the humidity meters for environmental monitoring and assessment purposes.
Keywords
Cellulose, Environmental monitoring, Humidity, Impedance, Poly-N-epoxypropylcarbazole (PEPC).
Citation
M. TARIQ SAEED, F. AHMAD KHALID, KH. S. KARIMOV, M. SHAH, Organic Cu/cellulose/ PEPC/Cu humidity sensor, Optoelectronics and Advanced Materials - Rapid Communications, 4, 6, June 2010, pp.888-892 (2010).
Submitted at: March 12, 2010
Accepted at: June 16, 2010