Bio Physics

The new micro-device for fluid analysis will enable more tailored experiments in drug development ; and disease research via new ‘organ-on-chip’ systems. And also development and disease contamination testing and medical diagnosis in natural disaster zones, where its low cost; simple use and portability make it a practical tool almost anyone use. A simple innovation the size of a grain of sand means They can now analyze cells and tiny particles as if they were inside the human body.

Development and disease

Microfluidic or ‘lab-on-a-chip’ devices are commonly used to analyze blood and other fluid samples; which are pump through narrow channels in a transparent chip the size of a postage stamp. This new chip takes that technology one step further by adding a three-dimensional cavity along the channel  think of a narrow tunnel that suddenly opens into a domed vault – which creates a mini-vortex where particles spin around; making them easier to observe.

To make this cavity, researchers insert a liquid metal drop onto the silicon could when making the chip. The liquid metal’s high surface tension means it holds its form during the molding process. Finally the liquid metal is remove; therefore leaving just the channel and a spherical cavity ready to use as a mini-centrifuge; explained RMIT engineer and study co-leader Dr Khashayar Khoshmanesh.

Liquid metal is remove

“When the fluid sample enters the spherical-shaped cavity, it spins inside the cavity;” he said. “This spinning creates a natural vortex, which just like a centrifuge machine in an analytics lab; spins the cells or other biological samples; allowing them to be studied without the need for capturing or labeling them.” The device only requires tiny samples; as little as 1 ml of water or blood; and is use to study tiny bacterial cells measuring just 1 micron, all the way up to human cells as large as 15 microns.

Study co-leader and RMIT biologist, Dr Sara Baratchi, says the device’s soft spherical cavities are use to mimic 3D human organs and observe how cells behave in various flow conditions or drug interactions. “The ability to tailor the size of the cavity also allows for different flow situations to be simulate  this way we can mimic the response of blood cells under disturb flow situations, for example at branch points and curvatures of coronary and carotid arteries, which are more prone to narrowing,” she said.

Machine in an analytics lab

The same research group recently developed a pressure pump, made from latex balloons, to operate the device. Unlike conventional pumps, which can be as large as a shoebox and cost thousands of dollars, theirs is low cost and portable. “Simplicity is a very important parameter for our designs because that often translates to lower cost and great applicability outside the lab,” Khoshmanesh said.