| 摘要 |
A method for interrogating a surface of a sample bathed in electrolyte solution using SICM, comprising: controlling the potential between first and second electrodes bathed in the electrolyte solution to induce an ion current in the electrolyte solution, a submerged portion of the first electrode being contained within a micropipette and the second electrode being external to the micropipette; recording the ion current whilst controlling the micropipette to move with respect to a stage supporting the sample; and determining, from the ion current and calibration data, the surface height profile of the sample. Said potential can be controlled according to a spread spectrum modulated signal. Said micropipette motion can be according to an AC mode pattern having a modulation frequency greater than a resonant frequency of an assembly of the micropipette, first electrode and a first piezoelectric actuator configured to control z-axis motion of said micropipette. |
