Studying sperm motion inside microchannels

Until now, the mechanism of sperm navigation inside the female reproductive tracts to reach the oocyte is still not confirmed. Although, chemotaxis and thermotaxis have been suggested as possible mechanisms, the former is though to be more prevalent in marine species whereas the latter have been dismissed by some recent studies. Very recently, Rheotaxis, which is sperm cell tendency to swim against the flow, has been suggested as a possible mechanism for directing sperm cells to the oocyte when they swim against the fluid secreted in the female reproductive system after coitus. In this project we characterize rheotaxis of bull sperm using microfluidics.

To learn more about this project, read our recent paper in Integrative Biology: Characterization of Rheotaxis of Bull Sperm Using microfluidics.

As part of this project, we have developed a new Computer Assisted Sperm Analysis (CASA) Plugin for analyzing sperm in microfluidic environments using Image-J. This plugin improves on a previously reported CASA plugin for easier user interaction, better accuracy, and added functionality in microfluidics.

You can learn more about our newly developed CASA plugin in our recent paper in Theriogenology: Development of Computer Assisted Sperm Analysis (CASA) Plugin for analyzing sperm motion in microfluidic environments using Image-J. You can download our plugin to use it in your own projects here. You can also check the Audioslides of our Theriogenology paper below:

The CASA plugin we developed is currently being used in some labs in Canada, India, and Japan. Check the map below for exact location of these laboratories.

CASA plugin developed at AML

Building a microfluidic chip to determine mechanical properties of biological cells

Mechanical properties of biological cells bear a significant relationship with the health state of the cell. Some diseases increase mechanical stiffness of cells as in the case of Malaria with red blood cells, whereas others decrease cell stiffness as in many reported cancer types. The aim of this project is to build a chip that measures mechanical stiffness of different cells to use it as a biomarker for different diseases.

Modeling droplet actuation in digital microfluidics

Electrodynamic forces induced on droplets in digital microfluidics are dependent on many factors such as electrical properties of the liquid being manipulated, electrode shape, actuation frequency, and device geometrical parameters. By simulating droplet actuation numerically, the effect of liquid properties and actuation frequency on electrodynamic forces generated on droplets and on droplet motion will be understood, which should enable more efficient device designs based on the intended application.

Studying contact angle saturation in electrowetting

When the potential of a sessile droplet sitting on a hydrophobic surface is biased relative to the electrode beneath the droplet, the electrodynamic forces generated on the droplet spread it on the surface which reduces its contact angle. This electrically-induced wetting, called Electrowetting, has extensive applications in optics such as variable focal length lenses and flexible displays. The aim of this project is to use energy modeling to find an explanation for the contact angle saturation phenomenon in electrowetting where the droplet contact angle ceases to decrease at a certain voltage contrary to the predictions o the famous Young-Lippmann equation.
You can check the new model we developed in our recent paper in Biomicrofluidics: Repulsion Based Model for Contact Angle Saturation.

Low cost digital microfluidics for exploratory research and educational purposes

In this project we target spreading digital microfluidics technology into the academic community for exploratory research and educational purposes by integrating rapidly prototyped devices with a portable and inexpensive setup to generate and control the high potentials required for droplet manipulation. We believe such combination will encourage researchers with non-engineering backgrounds, in Egypt and worldwide, to test digital microfluidics as a useful tool in their respective fields. Such low cost and accessible adaptation should promote the technology and generate novel applications.
Mohamed Abdelgawad,
May 9, 2010, 9:25 AM