There are four methods for modeling free liquid surfaces in the COMSOL Multiphysics® software: level set, phase field, moving mesh, and stationary free surface. In the first part of this blog series, we discuss the level set and phase field methods, which are field-based methods that describe almost any type of free liquid surface. In part two, we will compare the results from this post with those obtained using the Moving Mesh interface for solving free surface problems.

Generating complex emulsion droplets that can be used to fabricate highly compartmentalized microconstructs is difficult to achieve with classic droplet-forming fluidic junctions. These junctions have simple geometries, which can result in a narrow range of flow rate control. To address this issue, one research group designed an oscillatory microfluidic junction with a more complicated geometry. This junction, called the bat-wing junction, can consistently produce uniform and complex double-emulsion droplets, with bespoke components and encapsulated reagents.

If an inkjet printhead nozzle is poorly designed, it will lead to a low-quality end product — whether it’s used in a 2D or 3D printer, the fabrication of an integrated circuit, or even DNA synthesis. With simulation, you can determine the ideal printhead nozzle dimensions to achieve precise material deposition. And with the COMSOL Multiphysics® simulation software, you can save time by turning your model into an app for use by other project stakeholders.

In any form of treatment, it is always desirable to minimize the level of discomfort that the treatment process causes patients, while ensuring overall safety and effectiveness. For diabetes patients, insulin injections remain an important form of treatment, but the process itself can be painful. With the help of multiphysics simulation, a team of researchers from the University of Ontario Institute of Technology sought to develop a MEMS-based micropump that could administer insulin injections in a safe and painless way.

In COMSOL Multiphysics version 5.2, the CFD and Microfluidics modules include a new fluid flow interface for modeling separated three-phase flow. The model behind this fluid flow interface accounts for surface tension between each pair of fluids, contact angles with the walls, as well as the density and viscosity of each of the fluids. The phase field method computes the shape of the interfaces between the three phases and also accounts for interactions with walls.

Fusion energy is 30 years away — and always will be. The joke certainly rings true for inertial fusion energy (IFE), which must overcome a number of obstacles before it can become a reality. For example, the current methods for creating IFE targets cannot meet the predicted demand and cost requirements. To solve this problem, researchers designed a new microfluidics method that could address these production bottleneck issues while complying with the strict geometrical requirements of IFE target design.

The viscous catenary problem has generated a lot of theoretical and experimental interest in recent years. This is due to the industrial importance of the rich phenomena that occur within it. Using the flexibility of the COMSOL Multiphysics® software, we can gain fundamental insights into complex problems like the viscous catenary problem and determine the validity of the assumptions made in previous analyses.

Transdermal drug delivery (TDD) patches continuously deliver drugs into the body for a certain amount of time. However, the skin is designed to keep out foreign substances, like drugs. To create a TDD patch that successfully bypasses this barrier, simulation can be used to study drug release and absorption into the skin. To analyze this process, Veryst Engineering created a TDD patch model with the COMSOL Multiphysics® software and compared the results to experimental data.

When you think of a stout beer, one type that may come to mind is Guinness® beer. This stout is very special, noticeable by its dark body and famous white head. The dynamics of the foam alone are interesting enough to write a series of blog posts about. Although I don’t drink Guinness® beer (I’m a fan of IPA), I found the longstanding debate about whether its bubbles are rising or sinking while the beer settles makes an interesting simulation.

Adjusting the focal length of a camera lens allows you to change your angle of view. Miniature lenses can achieve this change by using a method called electrowetting. Electrowetting involves changing the balance of forces at a contact point of a free surface and a solid by applying a voltage. However, focus is not obtained immediately due to oscillations in the free surface. Here, we investigate the optimal viscosity for critically damping the free surface when a voltage is applied.