Researchers have invented a technique that uses inexpensive paper to make ‘microfluidic’ devices for rapid medical diagnostics and chemical analysis. Current lab-on-a-chip technology is relatively expensive because chips must be specifically designed to perform certain types of chemical analyses, with channels created in glass or plastic and tiny pumps and valves directing the flow of fluids for testing. But the chips, which are roughly palm-size or smaller, are difficult to design and manufacture. The new technique is simpler because the testing platform will be contained on a disposable paper strip containing patterns created by a laser. The researchers start with paper having a hydrophobic (or water-repellant) coating, such as parchment paper or wax paper used for cooking. A laser is used to burn off the hydrophobic coatings in lines, dots and patterns, exposing the underlying water-absorbing paper only where the patterns are formed. “Our process is much easier because we just use a laser to create patterns on paper you can purchase commercially and it is already impregnated with hydrophobic materia. It's a one-step process that could be used to manufacture an inexpensive diagnostic tool for the developing world where people can't afford more expensive analytical technologies,” said Babak Ziaie, a Purdue University professor of electrical and computer engineering and biomedical engineering. More information can be found here: