Walter Presz - Academia.edu (original) (raw)
Uploads
Papers by Walter Presz
2018 IEEE International Ultrasonics Symposium (IUS), 2018
A novel method of separating, sorting and differentiating various particles using macroscale bulk... more A novel method of separating, sorting and differentiating various particles using macroscale bulk ultrasonic standing waves oriented at an angle relative to the fluid velocity is presented. This technique offers a sensitive separation capability with respect to size and acoustic contrast of particles. An analytical model for particle deflection is presented and universal curves are developed for all possible wave angles as a function of a non-dimensional parameter, M, defined by the ratio of acoustic radiation force to viscous drag force. Using this parameter, deflection angle can be accurately predicted for any particle of known properties. Experimental results verify the analytical model and the universal curve for different M parameters. The angled wave system shows 90+% efficiency in separating Jurkat T-cells and calibrated beads.
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
Acoustic standing wave fields are widely used in MEMS applications to manipulate micron sized par... more Acoustic standing wave fields are widely used in MEMS applications to manipulate micron sized particles in fluids with typical fluid channel dimensions of half a wavelength. This report presents three novel acoustofluidic platforms for particle separation and/or manipulation at macroscale, i.e., tens to hundreds of wavelengths. The first platform uses multidimensional standing waves which generate lateral radiation forces that trap and tightly cluster suspended fluid or particulate, enhancing the gravitational settling effect that results in continuous, macroscale separation. The second platform employs acoustic radiation forces generated near the edge of an acoustic standing wave to hold back particles and generate a wall type separation effect. The third platform uses the acoustic radiation forces generated by a macroscale, angled standing wave to deflect particles in a controlled fashion for particle manipulation and/or differentiation. Applications are focused in biopharmacy and cellular and gene ther...
The Journal of the Acoustical Society of America
There is currently a shift in Bioprocessing towards continuous manufacturing of monoclonal antibo... more There is currently a shift in Bioprocessing towards continuous manufacturing of monoclonal antibodies or recombinant proteins in perfusion mammalian cell cultures (Konstantinov & Cooney, Journal of Pharmaceutical Sciences, 2015). A cell retention device is the key technology component that enables the shift to continuous production. A novel acoustic cell retention device operates by continuously drawing off a harvest flow, equal to the perfusion rate of the bioreactor, while recirculating the retained cells back to the bioreactor. The harvest flow path is tangent and significantly smaller than the recirculation rate. The device utilizes a novel acoustophoretic effect known as an “acoustic edge/interface” effect in conjunction with a recirculating flow beneath the acoustic harvest chamber which collects and returns cells to the bioreactor. This interface effect operates by creating a radiation pressure/force field at the interface between cell-free harvest and cell-laden circulating fluids. Numerical resul...
2018 IEEE International Ultrasonics Symposium (IUS), 2018
A novel method of separating, sorting and differentiating various particles using macroscale bulk... more A novel method of separating, sorting and differentiating various particles using macroscale bulk ultrasonic standing waves oriented at an angle relative to the fluid velocity is presented. This technique offers a sensitive separation capability with respect to size and acoustic contrast of particles. An analytical model for particle deflection is presented and universal curves are developed for all possible wave angles as a function of a non-dimensional parameter, M, defined by the ratio of acoustic radiation force to viscous drag force. Using this parameter, deflection angle can be accurately predicted for any particle of known properties. Experimental results verify the analytical model and the universal curve for different M parameters. The angled wave system shows 90+% efficiency in separating Jurkat T-cells and calibrated beads.
The Journal of the Acoustical Society of America
The Journal of the Acoustical Society of America
Acoustic standing wave fields are widely used in MEMS applications to manipulate micron sized par... more Acoustic standing wave fields are widely used in MEMS applications to manipulate micron sized particles in fluids with typical fluid channel dimensions of half a wavelength. This report presents three novel acoustofluidic platforms for particle separation and/or manipulation at macroscale, i.e., tens to hundreds of wavelengths. The first platform uses multidimensional standing waves which generate lateral radiation forces that trap and tightly cluster suspended fluid or particulate, enhancing the gravitational settling effect that results in continuous, macroscale separation. The second platform employs acoustic radiation forces generated near the edge of an acoustic standing wave to hold back particles and generate a wall type separation effect. The third platform uses the acoustic radiation forces generated by a macroscale, angled standing wave to deflect particles in a controlled fashion for particle manipulation and/or differentiation. Applications are focused in biopharmacy and cellular and gene ther...
The Journal of the Acoustical Society of America
There is currently a shift in Bioprocessing towards continuous manufacturing of monoclonal antibo... more There is currently a shift in Bioprocessing towards continuous manufacturing of monoclonal antibodies or recombinant proteins in perfusion mammalian cell cultures (Konstantinov & Cooney, Journal of Pharmaceutical Sciences, 2015). A cell retention device is the key technology component that enables the shift to continuous production. A novel acoustic cell retention device operates by continuously drawing off a harvest flow, equal to the perfusion rate of the bioreactor, while recirculating the retained cells back to the bioreactor. The harvest flow path is tangent and significantly smaller than the recirculation rate. The device utilizes a novel acoustophoretic effect known as an “acoustic edge/interface” effect in conjunction with a recirculating flow beneath the acoustic harvest chamber which collects and returns cells to the bioreactor. This interface effect operates by creating a radiation pressure/force field at the interface between cell-free harvest and cell-laden circulating fluids. Numerical resul...