Atomic force microscope tip spontaneous retraction from dielectric surfaces under applied electrostatic potential

Ultramicroscopy. 2006 Aug-Sep;106(10):909-13. doi: 10.1016/j.ultramic.2006.04.002. Epub 2006 May 24.

Abstract

A time-resolved method for tip' retraction at micros-scale away from dielectric surfaces has been developed. Analysis of the forces in the system comprising AFM tip, water meniscus, and polymer film suggests that an electrostatic repulsion of the tip from the surface in the double-layered (water and polymer) system, and water condensation in the tip-surface junction are the dominant factors enabling the mechanical work for tip retraction. Nanostructures of 5-80 nm height are formed in polymeric surfaces as a result. This interesting physical phenomenon could be used for nanostructures patterning in polymeric materials at enhanced aspect ratio.