Microfluidics Blog Posts
Focusing on an Electrowetting Lens
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.
Creating Ultrafast Polymerase Chain Reaction Tests with LEDs
Polymerase chain reaction tests have many applications within medical and biological research. In the past, these tests have been performed within a laboratory setting due to their high power requirements and the slow speed at which results are delivered. Researchers at the University of California, Berkeley have developed a new LED-based polymerase chain reaction system that, with its simplicity and speed, could be used in point-of-care testing.
Simulating a Valveless Micropump Mechanism
Microfluidic systems often rely on valveless pumps, as they are both gentle on the biological material and low in the risk of clogging. However, by design, this type of pump is not suitable for viscous fluids and systems with small length scales or low flow rates. To overcome this limitation, you can introduce a micropump mechanism that converts oscillatory fluid motion into a unidirectional net flow.
Simulating Analog-to-Digital Microdroplet Dispensers for LOCs
Microfluidic biochips have a variety of applications and are valued for their low cost, fast response time, and high efficiency. In the paper “Design and Simulation of High-Throughput Microfluidic Droplet Dispenser for Lab-on-a-Chip Applications”, which was presented at the COMSOL Conference 2014 Boston, researchers designed a microfluidic biochip with an analog-to-digital converter. They used COMSOL Multiphysics software to understand the mechanism of the device and verify its function.
Tears of Wine and the Marangoni Effect
Try pouring some wine into a glass. Don’t drink it yet — this is a scientific experiment. When you hold up your glass, you’ll see what look like teardrops running down the sides. These tears of wine are caused by the Marangoni effect, which describes a mass transfer along the surface of two fluid phases caused by surface tension gradients along the interface between the two phases (for example liquid and vapor).
How can you use an electric field to control the movement of electrically neutral particles? This may sound impossible, but in this blog entry, we will see that the phenomenon of dielectrophoresis (DEP) can do the trick. We will learn how DEP can be applied to particle separation and demonstrate a very easy-to-use biomedical simulation app that is created with the Application Builder and run with COMSOL Server™.
Buoyancy-Driven μPCR for DNA Amplification
DNA is a complex molecule that contains instructions for life and often referred to as a “digital fingerprint” or code telling a cell what to do. DNA is often the only means for accurate testing and identification of biomolecules, cells, or even an entire person during forensic investigations. The need to be able to test for DNA, as quickly as possible, and even at the site where the sample is taken, is becoming more and more important.
Red Blood Cell Separation from a Flow Channel
Before conducting certain blood sample analyses, researchers need to separate the red blood cell particles from the blood plasma. Using lab-on-a-chip (LOC) technology, red blood cell separation can be achieved via magnetophoresis (i.e., motion induced by magnetic fields). Since the magnetic permeability of the particles is different from the blood plasma, their trajectory can be controlled within the flow channel of the LOC device and then separated out from the fluid.
- COMSOL Now
- Today in Science