A new design of AC-based ECT sensor to monitor sub-micron droplet distribution in cross-section of EHDA encapsulation chamber

Electro-hydro-dynamic Atomization (EHDA) has recently been applied to the fabrication of polymeric micro- or nano-particles or fibres for drug encapsulation. For in-situ monitoring of pharmaceutical particle fabrication in an EHDA encapsulation chamber, AC-based Electrical Capacitance Tomography (ACECT) has been used as a non-invasive measurement technique. Thekey achievements made during this study include the successful monitoring of very dilute droplet and particle trajectories in different regions of EHDA encapsulation chamber. A new type of ACECT sensor with internal and external electrodes is designed, fabricated and used to improvethe sensitivity of ACECT measurement for detection of the objects in the central area of theEHDA encapsulation chamber. The final results confirm that the monitoring droplet and particles in low concentration which was a serious problem in older generations of ACECT systems hasbeen solved by using an internal-external electrode sensor in this work. The final results also show that the ACECT system is not significantly influenced by the high electric field strength

Keywords:

AC-based Electrical Capacitance Tomography (ACECT) , Electro-hydro-dynamic Atomization (EHDA) , EHDA encapsulation chamber , internal-external electrodes sensor , droplet trajectory