High-throughput optical characterization of colloidal particles
Begeleider(s): ir. Stijn Vandewiele


Particle characterization is a necessity for a whole range of applications such as E-ink displays, liquid toner printers, pharmaceutical applications and bio-assays. The commercially existing methods to analyse such particles suffer from a number of short-comings: they are either not sensitive enough or lack the possibility to investigate multiple parameters (size, refractive index, shape, electrical charge). In our group a single-particle based analysis technique is developed which is both sensitive and versatile. Because currently the analysis of a particle sample still takes too much time, the method should become completely automated.


The aim of this Master thesis is fabricating a microfluidic device for high throughput analysis of liquid toners and inks for e-ink displays on a particle-to-particle basis. With this device a continuous flow of particles is sent through a vertical channel. Using optical microscopy and LabView software images of each particle are acquired at different positions with respect to the microscope focus. Image decomposition and analysis in Matlab then results in a unique ‘optical fingerprint’ for each particle. These fingerprints hold information on the size, refractive index and shape of the particle. Depending on the preference of the student the focus of the thesis can be more on developing imaging software (LabView), analysis software (Matlab), fabricating microfluidics devices (cleanroom Zwijnaarde) or microscopy experiments (Technicum).