Enabling & Support

Simplified Dynamic Light Scattering System to Resolve Sizes of Particles And Visco-Elastic Properties Of Gases And Fluids

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ESA / Enabling & Support / Space Engineering & Technology
410 - Abstract:
The European Space Agency has developed a method and apparatus to resolve sizes of particles and visco-elastic properties of gases and fluids. The dynamic light scattering method described can replace scattering angle dependent measurements currently employed. It allows a faster, simultaneous, wavelength dependent characterization from a single position. Potential applications are in medicine, in production control and in industrial emission control systems. Further it can be applied in atmospheric control of ozone, aerosols and clouds. License agreements are sought.


The present technology relates to a dynamic light scattering apparatus and method. A sample is illuminated by laser light of wavelengths ranging from the visible to the near infrared. The fluctuations in light scattered or fluoresced by the sample at each wavelength are detected. The apparatus comprises a discrete numbers of transmitting lasers. The laser light emitted propagates to the sample via apertures, focusing, telescope and/or fibre optical elements. Corresponding collectors receive each wavelength of scattered light separately and simultaneously. This quasi-simultaneous, multiple channel mode of operation replaces the scattering angle scans currently in use in dynamic light scattering systems. 

The method may be employed for measuring the size of particles or macro-molecules and for determining visco-elastic properties of gases, fluids and suspensions. Features of the method described allow application in remote sensing of atmospheric properties, like the control of ozone, aerosols and clouds. In medical diagnostics the method may be used for reading the results of immune assays. In ophthalmology, it allows angle-dependent measurements under in vivo conditions: for instance the changes in the vitreous body as a function of age may be assessed. In production control and in industrial emission control particle size distributions, emission rates and factors, and potential exposures may be determined.

Innovations and advantages:

In dynamic light scattering (DLS) normal practice is to detect the scattered photon intensity at a range of different scattering angles, typically from 10° to 180°. However, such procedures are time-consuming because of the number of readings that need to be taken, and require expensive sensors (goniometers). The described measurement of light scattering or fluorescence at different wavelengths is done in one shot instead of a scan and consequently is faster. Characterization is done from a single position, thus the device will be smaller. This is not only important in atmospheric research but also in medical applications.

Domain of application:

Applications and Markets

Potential non-space applications:

  • Medical applications
  • Industrial emission control systems0
  • Atmospheric Sciences.