Recent advances in atomic force microscopy for micro- and nanobubble research

Area of Science:

• Interfacial Science
• Colloid and Surface Chemistry
• Soft Matter Physics

Background:

• Micro- and nanobubbles are critical in porous media and complex fluids, influencing multiphase transport, wettability, mass transfer, and interfacial reactivity.
• Their technological relevance in energy, environmental, and industrial processes is significant, yet a mechanistic understanding at micro- and nanoscales is limited by interface softness and dynamics.

Purpose of the Study:

• To provide a unified overview of atomic force microscopy (AFM)-based strategies for investigating micro- and nanobubbles.
• To highlight recent advances and methodological optimizations of AFM for studying soft interfacial systems.
• To establish an integrated framework linking AFM methodology with fundamental interfacial physics and applied bubble science.

Main Methods:

• Methodological optimization of AFM for soft interfacial systems.
• AFM-enabled characterization of bubble morphology, mechanics, rheology, stability, and interfacial forces.
• Recent developments including colloidal probe AFM (oil-droplet and bubble probes, fluidic force microscopy), multimodal, and high-speed AFM.

Main Results:

• AFM strategies enable detailed characterization of micro- and nanobubble properties.
• Advanced AFM techniques offer in situ, time-resolved visualization of bubble nucleation and dynamics.
• An integrated framework is established connecting AFM methodology to interfacial physics and bubble science.

Conclusions:

• AFM is a powerful tool for understanding micro- and nanobubbles, crucial for various industrial applications.
• Recent AFM advancements facilitate in situ and dynamic studies of bubble behavior.
• Future directions involve addressing key challenges to further advance micro- and nanobubble research.