Device, system and method for the detection and screening of plastic microparticles

Inventors

Knox, Wayne H. • Madejski, Gregory • McGrath, James Lionel

Assignees

University of Rochester

Abstract

A device, system and method for the detection and screening of plastic microparticles in a sample is disclosed. A nanoporous silicon nitride membrane is used to entrap plastic microparticles contained in the sample. The sample may be a water sample, an air sample, or other liquid or gas sample. The entrapped plastic microparticles are then heated or otherwise processed on the nanoporous silicon nitride membrane. An imaging system observes the nanoporous silicon nitride membrane with the entrapped plastic microparticles to determine the type and quantity of the various plastic microparticles that are entrapped on the membrane.

Core Innovation

The invention relates to a method for the detection and screening of plastic microparticles in a sample by delivering the sample through a porous membrane and entrapping microparticles on the porous membrane. The method provides an increasing temperature profile to the porous membrane, observes a phase change of the entrapped microparticles, and records the temperature at which the entrapped microparticles change phase. The recorded temperature associated with the phase change is used to infer characteristics of the entrapped plastic microparticles as part of plastic type determination and quantity determination.

The description emphasizes recording temperature-related melting and glass-transition behaviors to infer polymer type, based on the observed phase change and the temperature at which the change occurs. The approach is coupled to observation of the phase change via a microscope or imaging system and, in some implementations, machine vision observation. This enables an automated workflow where segmentation, classification, and enumeration are performed using computer vision and machine learning.

The invention also supports alternative or multimodal identification modalities in addition to temperature-profile based phase-change observation, including EDS elemental composition, Nile Red fluorescence, Raman, birefringence or thermobirefringence, energy-dispersive X-ray spectroscopy, and SEM or optical imaging. Across these modalities, the core workflow remains centered on entrapping plastic microparticles on a porous membrane and using observed phase-change behavior together with recorded temperature information.

Claims Coverage

The partial claim set includes two independent claims. Both independently require delivering a sample through a porous membrane to entrain or entrap microparticles, providing an increasing temperature profile, observing a phase change of the entrapped microparticles, and recording the temperature at which the entrapped microparticles change phase. Dependent claims add machine learning observing, computer-based recording, and determining plastic microparticle type from the recorded phase-change temperature.

Overall, the independent claims cover membrane-based entrapment of plastic microparticles combined with an increasing temperature profile, observation of phase change, and recording the temperature at which the phase change occurs; dependent refinements specify observing using a machine learning tool, recording using a computer, and determining the type of an entrapped microparticle based on the recorded phase-change temperature.

Stated Advantages

Documented Applications