The electrode, that staple of hospitals and medical dramas alike, may soon exit stage left. Researchers have designed a wireless electronic monitoring device so thin it can be applied to the skin like a temporary tattoo. It could one day be used to monitor heart, brain and muscle activity of patients without their even noticing. The research, released Thursday in the journal Science, could rid hospitals of the unwieldy, outdated monitoring systems, which often involve needles, webs of wires and conductive gels. "Such complicated wiring can be inconvenient and distressing for both patients and physicians," Zhenqiang Ma, an engineering professor at the University of Wisconsin who was not involved in the research, wrote in a commentary on the study. Patients with heart disease may have to wear bulky monitors for a month to try to catch rare cardiac events, he explained. A more streamlined, wearable, integrated system would appear to be a relief to all. But designing a chip flexible enough to stretch, squeeze and twist with the skin is no easy task, said study coauthor John Rogers, a materials scientist with the University of Illinois at Urbana-Champaign.