Atomic force microscope

An apparatus, comprising:

• a sample stage to support a sample;
• a cantilever mount to mechanically fix a mechanical cantilever having a scanning tip;
• a cantilever-force detector to produce an electronic cantilever-force error signal;
• a cantilever feedback system configured to electromechanically drive the mechanical cantilever in a manner responsive to the cantilever-force error signal;
• an electromechanical driver fixed to the cantilever mount;
• and
• a tuning fork being fixed to the electromechanical driver and having the scanning tip, the electromechanical driver being configured to move the tuning fork in a manner responsive to a driving signal;
• and
• wherein the cantilever-force detector is configured to produce the error signal responsive to a variation of an electrical property of the tuning fork.

An apparatus for an atomic force microscope, comprising:

• a sample platform to support a sample;
• a cantilever mount to mechanically fix a cantilever having a scanning tip;
• a cantilever-force detector to produce an electronic error signal substantially representative of a force exerted by the sample on the tip;
• a cantilever feedback system configured to receive the error signal and to electromechanically drive the tip responsive to the received error signal;
• a high-pass filter being configured to produce a filtered driving signal responsive to the error signal;
• a sample stage feedback system being configured to cause a displacement by the sample platform responsive to the error signal;
• and
• an electromechanical driver configured to receive the filtered driving signal and to displace a portion of the cantilever responsive to said filtered driving signal;
• wherein the high-pass filter is configured to cause the electromechanical driver to operate in the absence of zero and low frequency drive voltages.

An apparatus for an atomic force microscope, comprising:

• a sample platform to support a sample;
• a cantilever mount to mechanically fix a cantilever having a scanning tip;
• a cantilever-force detector to produce an electronic error signal substantially representative of a force exerted by the sample on the tip;
• a cantilever feedback system configured to receive the error signal and to electromechanically drive the tip responsive to the received error signal;
• a high-pass filter being configured to produce a filtered driving signal responsive to the error signal;
• an electromechanical driver configured to receive the filtered driving signal and to displace a portion of the cantilever responsive to said filtered driving signal;
• and
• a tuning fork fixed to the electromechanical driver and having the scanning tip thereon;
• and
• wherein the cantilever-force detector is configured to produce the error signal responsive to a variation of an electrical property of the tuning fork.

A method of operating an atomic force microscope, comprising:

• laterally scanning a tip of a flexible mechanical cantilever over a surface of a sample;
• while performing the scanning, producing an error signal substantially representative of a force exerted by the sample on the cantilever;
• while performing the scanning, driving the mechanical cantilever with an electromechanical driver in a manner responsive to the error signal;
• and
• while performing the scanning, driving a platform holding the sample such that the platform undergoes a motion responsive to the error signal;
• and
• wherein the driving by the electromechanical driver produces a displacement of the cantilever without a substantial zero-frequency component.