Microfluidic chip could aid food safety

A new process for making a 3D microstructure that can be used to analyse cells could be useful in counterterrorism measures and water and food safety concerns.

Researchers from Virginia Tech’s Microelectromechanical Systems (MEMS) Laboratory developed a new microfabrication technique to develop 3D microfluidic devices in polymers.

Masoud Agah, Associate Professor of the Bradley Department of Electrical and Computer Engineering, and Amy Pruden, Professor of Civil and Environmental Engineering and Virginia Tech, have received a National Science Foundation (NSF) award of US$353,091 to use the technology to develop new microchips for pathogen detection.

The microchips are called 3D-πDEP, which stands for ‘three-dimensional, passivated-electrode, insulator-based dielectrophoresis’.

The NSF funding will allow them to focus on the isolation of waterborne pathogens, which claim the lives of about 2.5 million people each year.

In the past, Agah said, researchers have mainly used 2D microfluidic structures since this type of fabrication is more simplistic. With the 3D device developed by Agah and his collaborators Yayha Hosseini and Phillip Zellner, they are able to customise the shapes of the channels and cavities of the devices the fluids passed through.

The advantage of the fabrication process is that with a very economical technique it creates three-dimensional varying channels and cavities in a microfluidic structure with rounded corners as well as many other customised shapes. These shapes are important because they resemble the living conditions as they occur naturally and this allows the use of the three-dimensional microfabrication technology beyond pathogen detection.

As an example, in human blood vessels, cells interact with each other and their surrounding environment inside circular channels. They have varying diameters, along with multiple branching and joints.

“Only under this type of condition can one truly study the biology of cells within a system in vitro as if it is occurring in vivo - our new microfluidic fabrication technology can resemble more realistically the structures of a cell’s true living conditions,” Agah said. It is the introduction of the three dimensions that provides this distinctive environment.

The researchers used the material polydimethylsixolane, known for having elastic properties similar to rubber. This material is already widely used because of its transparency, biocompatibility and low cost.

Microfluidic devices can be used to trap and sort living organisms such as bacteria, viruses and cells. With this new 3D device that has a higher sensitivity and throughput than the 2D version, according to Agah, he is able to make their predictions of applications ranging from water and food safety to fighting biological and chemical terrorism and to healthcare by fishing for abnormal cells in body fluids.

“Our work establishes a reliable and robust, yet low-cost technique for the fabrication of versatile 3D structures in polydimethylsixolane,” Agah said.

Source: AlphaGalileo