Ordered SnO2 nanostructures were prepared as humidity sensors by nanosphere lithography with the magnetron sputtering technique. The X-ray diffraction patterns of SnO2 nanostructures show that all intense diffraction peaks correspond to the crystallographic planes of SnO2. The Atomic Force Microscope (AFM) mage shows that these SnO2 nanostructures exhibited a classic honeycomb structure. The resistance of this sensor was measured to show that the resistance of the sensor decreases with an increase from lower relative humidity (RH) to higher RH. Additionally, the longest response/recovery time was 32 s/42 s for 11–96% RH. The hysteresis for the SnO2 nanostructure sensor was <5%.
