Researchers have developed a nanobiodevice that can quickly and effectively separate microRNA, short lengths of ribonucleic acid present in bodily fluids, from mixtures of nucleic acids. The nanobiodevice contains a unique array of nanopillars that form a strong electric force under an applied electric field, allowing high-resolution separation of microRNA in less than 100 ms. Because microRNA is a biomarker for cancer, this technology may provide a simple, noninvasive approach for detecting cancer.