Multi-Set Point Intermittent Contact (MUSIC) Mode Atomic Force Microscopy of Oligothiophene Fibrils

Area of Science:

• Materials Science
• Nanotechnology
• Surface Science

Background:

• Atomic Force Microscopy (AFM) is crucial for nanoscale imaging.
• Traditional intermittent contact mode AFM requires feedback loops and is sensitive to lateral forces.
• Imaging very soft and fragile samples presents significant challenges for existing AFM techniques.

Purpose of the Study:

• To develop a novel AFM mode, MUSIC-mode, that overcomes limitations of intermittent contact mode.
• To enable simultaneous acquisition of height and phase images for soft and fragile materials.
• To characterize the nanomechanical properties and morphology of challenging samples.

Main Methods:

• MUSIC-mode AFM was developed, emulating intermittent contact mode without a feedback loop or lateral forces.
• The technique utilizes maps of amplitude-phase-distance curves for single-pass imaging.
• Simultaneous height and phase images are obtained across a range of amplitude set points.

Main Results:

• MUSIC-mode AFM successfully acquired height and phase images for various amplitude set points.
• The method proved advantageous for imaging very soft and fragile samples.
• The nanomechanical properties and shape of supramolecular oligothiophene aggregates were determined, revealing fibrils with rigid cores and soft shells.

Conclusions:

• MUSIC-mode AFM offers a robust single-pass approach for imaging soft and fragile materials.
• The technique provides simultaneous morphological and nanomechanical information.
• This advancement facilitates the study of complex nanostructures like oligothiophene fibrils.