Electrochemical force microscopy

A system for mapping dynamic charge screening, ionic diffusion, or electrochemical reactivity comprising:

• a current conductive cantilever, the cantilever being separated by a sample material through an electrolyte solution;
• a signal generator operable to provide an excitation signal to the cantilever, the excitation signal including a probing waveform component and an excitation waveform component, 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, the excitation signal inducing an electrical potential between the electrode and the sample material;
• a force detection sensor operable to measure the deflection of the cantilever over time;
• and
• a signal analysis module operable to determine, based on the output of the force detection sensor, a response of the cantilever as a function of a magnitude of the probing waveform and as a function of time.

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;
• establishing an electrical potential between the electrode and the sample material, the electrical potential being induced by an excitation voltage applied to the electrode or to the sample material, the excitation signal including a probing waveform component and an excitation waveform component, 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.