ANALYSIS ON ELECTROSTATIC TIP SAMPLE INTERACTION IN AQUEOUS-SOLUTION UNDER POTENTIOSTATIC CONDITION

Using a force microscopy, we investigated electrostatic tip-sample int eraction in aqueous solutions. A force between a gold-coated microsphe re tip and an oxidized silicon sample was measured with their surface potentials being controlled independently by bipotentiostat. The varia tions in the force characteristics were observed with the respective c hanges in the tip potential and the sample potential. The observed for ce characteristics were found to agree with the theory of electrical d ouble layer interaction under constant potential assumption.