Note: mechanically and chemically stable colloidal probes from silica particles for atomic force microscopy

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Colloidal probes are essential for atomic force microscopy (AFM) but are often limited by the material properties of the probe particle.
• Previous methods required low melting point materials like glass or latex, limiting probe durability and chemical resistance.
• Adhesives used in probe fabrication can introduce artifacts and contamination.

Purpose of the Study:

• To present a novel sintering-based method for preparing colloidal probes for AFM.
• To overcome limitations of previous colloidal probe fabrication techniques.
• To create robust silica colloidal probes with enhanced mechanical and chemical properties.

Main Methods:

• A novel sintering approach was employed to fabricate colloidal probes.
• An inorganic "fixation neck" was introduced to bond a silica particle to an AFM cantilever.
• Micrometer-sized silica particles were used as the probe material.

Main Results:

• The sintering method successfully created colloidal probes with an inorganic fixation neck.
• Silica colloidal probes demonstrated high mechanical strength, withstanding large forces.
• The absence of adhesives resulted in high chemical resistivity and well-defined surface chemistry.

Conclusions:

• The novel sintering technique provides a robust method for fabricating durable silica colloidal probes.
• These probes offer significant advantages in mechanical stability and chemical resistance for AFM applications.
• This approach expands the range of usable materials for colloidal probe fabrication in microscopy.