"This is a cutting-edge technology that has developed over the last decade from research at a handful of universities," said lead Aloke Kumar about his latest "lab-on-a-chip" collaboration. "A very important aspect is that we have achieved an integration of technologies that enables manipulation across a very wide length scale spectrum. This enables us to manipulate not only big-sized objects like droplets but also tiny DNA molecules inside droplets by using one combined technique. This can greatly enhance efficiency of lab-on-a-chip sensors."


The method of test comes from what is called a "hybrid optoelectric manipulation in microfluidics." First a red laser is used to position a droplet (water or other fluids). An infrared laser is then used to heat the droplets. An electrohydrodynamic effect causes the heated liquid to form a microfluidic vortex. (See more about electrohydrodynamic moving of a fluid here.) Like a micro centrifuge but more specific, the vortex is used to separate only the parts or particles in the liquid that are of interest. The platform comes from professor of mechanical engineering Steven T. Wereley at Purdue University. Wereley explained the benefit of this solution, "This works very fast. It takes less than a second for particles to respond and get pulled out of solution."


The team also plans on using the same technology in pharmasudical and nanomanufacturing. Wereley explained, "This is important for the field of pharmacy because a number of drugs are manufactured from solid particles suspended in liquid. The particles have to be collected and separated from the liquid. We can, say, collect all the particles that are one micron in diameter or get rid of anything bigger than two microns, so you can dynamically select which particles you want to keep." Nanomanufacturing comes in the form of assembling suspended particles, called colloids, into objects. The concept here is to build nano-scale electronics or mechanical parts.


All of the possibilities are some years away.


"The article is written by Wereley; Kumar; Stuart J. Williams, an assistant professor of mechanical engineering at the University of Louisville; Han-Sheng Chuang, an assistant professor in the Department of Biomedical Engineering at National Cheng Kung University; and Nicolas G. Green, a researcher at the University of Southampton."