Alignment-tolerant lens structures for acoustic force actuation of cantilevers

A probe-based instrument comprising:

• a cantilever;
• an acoustic actuator configured to direct a beam of acoustic energy at the cantilever so as to drive the cantilever;
• and
• an RF excitation signal passed to the acoustic actuator to generate the beam of acoustic energy, the RF excitation signal being spread over a frequency spectrum to reduce resonance effects of the signal.

A method of moving a cantilever of a probe-based instrument comprising:

• generating an RF excitation signal;
• passing the RF excitation signal to an acoustic actuator;
• and
• generating a beam of acoustic energy, from the RF signal, at the cantilever so as to drive the cantilever, wherein the RF excitation signal is spread over a frequency spectrum to reduce resonance effects of the signal.

A probe-based instrument comprising:

• a cantilever;
• an acoustic actuator configured to direct a beam of acoustic energy at the cantilever so as to drive the cantilever;
• and
• an RF excitation signal passed to the acoustic actuator to generate the beam of acoustic energy, the RF excitation signal being spread over a frequency spectrum to drive the actuation so that acoustic power perturbations caused by resonances and anti-resonances of different frequencies from the acoustic actuator act to neutralize each other.