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Gas embolotherapy (GE) is a developing medical method which can be utilized either as an autonomous therapeutic method to treat vascularized solid tumors, or it can be combined with other medical procedures-such as high-intensity focused ultrasound-to improve their efficiency. This paper is dedicated to investigating the different parameters which influence bubble lodging inside human vasculature via 2D-modeling of bubble dynamics in arteries' and arterioles' bifurcations which are potential sticking positions. Values used in the simulations are in accordance with the non-dimensional physiological numbers. It is found out that inlet pressure plays a decisive role in bubble lodging; the lower the value, the higher the possibility of bubble sticking. On the other hand, gravity has a counteracting effect on bubble lodging in arteries, but not on arterioles. The initial length of the bubble is not a determining factor in sticking behavior, even though it affects the flow rate behavior. Surface tension, another critical factor, has a semi-linear impact on bubble resisting power; lowering the surface tension will reduce bubble resistance to the flow, diminishing the possibility of bubble lodging. Finally, it is shown that lower values for the static contact angle impose higher resistance to the flow.

Volumetric additive manufacturing has a number of advantages as compared to conventional additive manufacturing methods, but it can still suffer from premature sedimentation in which the part sinks down during the printing process - especially in the final seconds- affecting the method’s geometric fidelity, resolution, and limits its applicability only to high-viscosity resins. In this study, a numerical model has been developed to investigate the effect of different material properties and process parameters on the sedimentation of the printed part. After a qualitative validation of the model, the role of the resin viscosity in the sedimentation phenomenon is elucidated, and it is shown how a rise in the cross-section ratio of the printed geometry to the container can reduce the sedimentation, while an increase in the curing time and the container’s rotation velocity can escalate the sinking of the part. Furthermore, it is found that raising the final density and viscosity of the curing material at the end of the print will worsen and mitigate the sinking effect, respectively. Finally, the effect of the orientation of the printed part on the sedimentation ratio is explored. The model developed herein illuminates a new avenue for better understanding the physics taking place during volumetric additive manufacturing, which is essential to further improve the applicability of the technology.

Microfluidic lab-on-chip devices are widely being developed for chemical and biological studies. One of the most commonly used types of these chips is perfusion microwells for culturing multicellular spheroids. The main challenge in such systems is the formation of substantial necrotic and hypoxic zones within the cultured spheroids. Herein, we propose a novel acoustofluidic integrated platform to tackle this bottleneck problem. We show that such an approach enhances cell viability and shrinks necrotic and hypoxic zones in these spheroid-on-a-chip platforms without the need to increase the flow rate, leading to a significant reduction in costly reagents' consumption. Proof-of-concept, designing procedures, and finite element numerical simulation are discussed in details. Also, the effects of acoustic and hydrodynamic parameters on the cultured cells are investigated. The results show that by increasing acoustic boundary displacement amplitude (d0), the spheroid’s proliferating zone enlarges greatly. Moreover, it is shown that by implementing d0=0.5 nm, the required flow rate to maintain the necrotic zone below 13% will be decreased 12 times compared to non-acoustic chips.

Microfluidic lab-on-chip devices are widely being developed for chemical and biological studies. One of the most commonly used types of these chips is perfusion microwells for culturing multicellular spheroids. The main challenge in such systems is the formation of substantial necrotic and quiescent zones within the cultured spheroids. Herein, we propose a novel acoustofluidic integrated platform to tackle this bottleneck problem. It will be shown numerically that such an approach is a potential candidate to be implemented to enhance cell viability and shrinks necrotic and quiescent zones without the need to increase the flow rate, leading to a significant reduction in costly reagents’ consumption in conventional spheroid-on-a-chip platforms. Proof-of-concept, designing procedures and numerical simulation are discussed in detail. Additionally, the effects of acoustic and hydrodynamic parameters on the cultured cells are investigated. The results show that by increasing acoustic boundary displacement amplitude (d0), the spheroid’s proliferating zone enlarges greatly. Moreover, it is shown that by implementing d0&nbsp, = 0.5 nm, the required flow rate to maintain the necrotic zone below 13% will be decreased 12 times compared to non-acoustic chips.

Converse to the conventional additive manufacturing methods based on constructing a body layer by layer, volumetric additive manufacturing produces the whole geometry at the same time. While it is faster, creates features with high surface quality, requires no overhang support structures, and can print in high-viscosity resins, all of which push the limits of additive manufacturing, this technique is still premature and suffers from some effects such as body sedimentation that impacts the geometric fidelity and resolution of the final product. The sedimentation rate of the printed body during its formation is highly dependent on the resin type, its viscosity, and its curing behavior. Herein, we propose a CFD model that takes into account the synergistic effect of reaction-based heating, curing behavior, and resin properties to predict the sedimentation rate of the printed geometry. The results show that heating effects can slow down the sedimentation rate of the curing part significantly.