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Microfluidic droplet deformation and non-spherical stability analysis
In this project, we propose to design microfluidic devices capable of deforming spherical micron-sized droplets. The deformation process needs to be characterized by varying the fluid properties of the two phases in the device, and this should enable us to design better devices to improve the stability of the non-spherical droplets.
Acoustic Droplet Vaporization (ADV) is a novel technique, wherein micron- and sub-micron-sized droplets are vaporized into microbubbles upon exposure to high-frequency ultrasound. This process can be used to improve the contrast in medical ultrasound imaging and for targeted drug delivery in the human body. However, the acoustic frequencies and incident pressures for achieving ADV are currently prohibitively high, and the process is thereby unsafe and difficult to perform. Therefore, it is necessary to find methods to reduce the required frequency and pressure. In this project, we propose to achieve this with micron-sized droplets that are non-spherical (e.g., ellipsoidal) in shape. To this extent, microfluidic devices capable of deforming spherical droplets (with an initial radius of ~ 60 μm) have been devised.
To understand the deformation, it is necessary to characterize how the process changes with varying surface tension, viscosity, and flow rates of the continuous and dispersed phases. It is also necessary to identify how these variables affect the temporal stability of the deformed ellipsoidal droplets (see Figure 1(d)) We would also like to find ways to deform much smaller droplets (radius ~ 15 – 20 μm). Additionally, our current devices introduce other unwanted variables that need to be eliminated. Therefore, new microfluidic devices should be designed to ensure controllable droplet deformation and to improve their stability.
Acoustic Droplet Vaporization (ADV) is a novel technique, wherein micron- and sub-micron-sized droplets are vaporized into microbubbles upon exposure to high-frequency ultrasound. This process can be used to improve the contrast in medical ultrasound imaging and for targeted drug delivery in the human body. However, the acoustic frequencies and incident pressures for achieving ADV are currently prohibitively high, and the process is thereby unsafe and difficult to perform. Therefore, it is necessary to find methods to reduce the required frequency and pressure. In this project, we propose to achieve this with micron-sized droplets that are non-spherical (e.g., ellipsoidal) in shape. To this extent, microfluidic devices capable of deforming spherical droplets (with an initial radius of ~ 60 μm) have been devised.
To understand the deformation, it is necessary to characterize how the process changes with varying surface tension, viscosity, and flow rates of the continuous and dispersed phases. It is also necessary to identify how these variables affect the temporal stability of the deformed ellipsoidal droplets (see Figure 1(d)) We would also like to find ways to deform much smaller droplets (radius ~ 15 – 20 μm). Additionally, our current devices introduce other unwanted variables that need to be eliminated. Therefore, new microfluidic devices should be designed to ensure controllable droplet deformation and to improve their stability.
The key objectives of this project are to first identify the correct operating regimes to achieve repeatable droplet deformation, and second, to improve the temporal stability of these deformed droplets.
The key objectives of this project are to first identify the correct operating regimes to achieve repeatable droplet deformation, and second, to improve the temporal stability of these deformed droplets.
Interested candidates can send an email with a recent transcript of records to aanunay@ethz.ch
Interested candidates can send an email with a recent transcript of records to aanunay@ethz.ch