Electrochemical force microscopy

摘要

A system and method for electrochemical force microscopy are provided. The system and method are based on a multidimensional detection scheme that is sensitive to forces experienced by a biased electrode in a solution. The multidimensional approach allows separation of fast processes, such as double layer charging, and charge relaxation, and slow processes, such as diffusion and faradaic reactions, as well as capturing the bias dependence of the response. The time-resolved and bias measurements can also allow probing both linear (small bias range) and non-linear (large bias range) electrochemical regimes and potentially the de-convolution of charge dynamics and diffusion processes from steric effects and electrochemical reactivity.

主权项

1. A method of mapping dynamic charge screening, ionic diffusion, or electrochemical reactivity comprising:
providing an electrode separated by a distance from a sample material and in electrical communication with the sample material through an electrolyte solution; applying an excitation voltage to the electrode to establish an electrical potential between the electrode and the sample material, the excitation voltage including a probing waveform component and an excitation waveform component superimposed thereon, wherein the probing waveform component includes a carrier waveform having a bias-on state and a bias-off state to elicit diffusion or faradaic reactions at the sample material, and wherein the excitation waveform component includes a frequency greater than a frequency of the probing waveform component to elicit double layer charging or charge relaxation at the sample material, the frequency of the excitation waveform component being between 5 kHz to 50 kHz inclusive, and the frequency of the probing waveform component being between 1 Hz to 10 Hz inclusive; and measuring a force response induced on the electrode by the electrical potential, the force response including the bias and time dependent local response of the sample material.