Advancing the science of dynamic airborne nanosized particles using Nano-DIHM

Area of Science:

• Aerosol science
• Microscopy
• Nanotechnology

Background:

• In situ and real-time aerosol characterization is crucial for atmospheric chemistry, air quality monitoring, and climate change studies.
• Existing digital holographic microscopy methods for dynamic nanosized particles often require optical traps.

Purpose of the Study:

• To introduce and demonstrate a novel integrated digital in-line holographic microscope coupled with a flow tube (Nano-DIHM).
• To characterize particle phase, shape, morphology, 4D dynamic trajectories, and 3D dimensions of airborne particles without optical traps.

Main Methods:

• Development of the Nano-DIHM system integrating a flow tube with digital in-line holographic microscopy.
• Application of the system for characterizing nanosized particles (≤200 nm) in dynamic systems.
• Utilizing automated software (Octopus/Stingray) for rapid hologram reconstruction and analysis.

Main Results:

• Demonstrated characterization of particle phase, shape, morphology, and 4D trajectories for particles from nanoscale to microscale.
• Successfully observed 100 nm and 200 nm particles in various phases (air, aqueous, solid, heterogeneous) without optical traps.
• Achieved high-time resolution (62.5 ms) analysis of thousands of holograms, validated by electron microscopy and aerosol sizers.

Conclusions:

• Nano-DIHM provides a powerful, trap-free method for in situ and real-time characterization of airborne particles.
• The system enables detailed exploration of complex physical and chemical aerosol processes.
• This technique advances aerosol research in atmospheric science, air quality, and climate change studies.