Perpustakaan Digital ITB

Porous Anodic Aluminum Oxide (AAO) using aluminum which had been deposited on paper substrate was fabricated. Aluminum which deposited on paper substrate had 800 nm - 1 μm of thickness. Anodization was carried out in 15 wt% phosphoric acid. There were two groups for anodization, various voltages and times. For the first groups, the voltage was varied from 60 V to 160 V, at 0 - 4°C during 300 s. For the second group, the time was varied from 90 to 900 s, at 0 - 4°C and 120 V. Based on SEM images of porous AAO surface and cross section, the porous AAO formed well when the aluminum was anodized at 120 V of voltage and 0 - 4°C for 300 s. Porous AAO which already fabricated was deposited by aluminum to design the electrode on its surface. The type of the electrode was interdigitated type. Then, it was applied for humidity sensor. Frequency 1 Hz to 1 MHz was used for measuring of capacitance of the sensor. The difference of its capacitance at low frequency was higher than the difference of its capacitance at high frequency. For this reason, 2 kHz of frequency was used to describe the relationship between capacitance of this sensor and various relative humidities (RH). The increase of capacitance was 6.9 pF from RH 20% to 70%, and it was 48.1 pF from RH 80% to 90%. The hysteresis was 1.09 pF at RH 20% and it is 5.95 pF at RH 60%.