Hyperspectral imaging of acoustically trapped plastics

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Hyperspectral (HS) imaging combines imaging and spectroscopy, creating spatial maps of spectral data.
• HS imaging requires managing background effects and immobilizing samples for accurate spectral analysis.
• Plastic pollution is a significant environmental concern requiring effective identification methods.

Purpose of the Study:

• To introduce acoustic trapping (AT) as a method for contactless, nondestructive immobilization of particles for HS imaging.
• To validate the combined HS-AT apparatus for identifying various plastics.
• To explore the potential of HS-AT for analyzing multi-component plastic samples.

Main Methods:

• Developed and applied an integrated acoustic trapping (AT) and hyperspectral (HS) imaging apparatus.
• Utilized contactless, nondestructive AT to immobilize plastic particles (up to several mm) for HS experiments.
• Employed fluorescent HS imaging and acoustically controlled rotation for sample analysis.

Main Results:

• Demonstrated distinguishable fluorescent spectral signatures for different acoustically trapped plastics using HS imaging.
• Showcased the HS-AT system's capability for tomographic spatio-spectral analysis of multi-component plastic samples.
• Validated the effectiveness of AT for immobilizing samples in HS imaging experiments.

Conclusions:

• The combined HS-AT system offers a novel approach for contactless and nondestructive particle immobilization in HS imaging.
• This method enables accurate identification of plastics based on their unique fluorescent spectral signatures.
• The HS-AT apparatus shows promise as a versatile benchtop device for material identification and analysis.