A big step forward in microfluidics has helped researchers develop stand-alone, self-powered chips that can diagnose diseases within minutes. The Self-powered Integrated Microfluidic Blood Analysis System (SIMBAS) can process whole blood samples without the use of external tubing and extra components.
"This is a very important development for global healthcare diagnostics," says UC Berkeley professor of bioengineering Luke Lee. “Field workers would be able to use this device to detect diseases such as HIV or tuberculosis in a matter of minutes."
The SIMBAS biochip uses trenches patterned underneath nanoscale microfluidic channels. When whole blood is dropped onto the chip’s inlets, the relatively heavy red and white blood cells settle down into the trenches, separating from the clear blood plasma. The blood moves through the chip in a process called degas-driven flow.
In experiments, the researchers were able to capture more than 99 percent of the blood cells in the trenches and selectively separate plasma using this method.
The team demonstrated the proof-of-concept of SIMBAS by testing a five-microliter sample of whole blood that contained biotin (vitamin B7) at a concentration of about 1 part per 40 billion.
The chip provided a readout of the biotin levels in 10 minutes.
"This is a very important development for global healthcare diagnostics. Field workers would be able to use this device to detect diseases such as HIV or tuberculosis in a matter of minutes. The fact that we reduced the complexity of the biochip and used plastic components makes it much easier to manufacture in high volume at low cost," says Lee.
"Our goal is to address global health care needs with diagnostic devices that are functional, cheap and truly portable."