Role of relative humidity in atomic force microscopy imaging

Atomic force microscope images were found to be influenced significantly by relative humidity. Higher relative humidity produces higher adhesion forces and reduced resolution. Atomic resolution on mica was abruptly lost when the relative humidity was slowly decreased while scanning. This effect could be reversed by increasing the relative humidity or by increasing the cantilever force. At higher relative humidities the lateral force on the tip was found to increase significantly with increasing scanning speed.