Two electronically active leads directly printed along the underside of graduate student Nick Williams’s pinky successfully light up an LED when a voltage is applied. (Credit: Duke) A new print-in-place technique for electronics is gentle enough to work on delicate surfaces including paper and human skin, researchers report. The advance could enable technologies such as high-adhesion, embedded electronic tattoos, and bandages tricked out with patient-specific biosensors. “When people hear the term ‘printed electronics,’ the expectation is that a person loads a substrate and the designs for an electronic circuit into a printer and, some reasonable time later, removes a fully functional electronic circuit,” says Aaron Franklin, associate professor of electrical and computer engineering at Duke University. “Over the years there have been a slew of research papers promising these kinds of ‘fully printed electronics,’ but the reality is that the process actually involves taking the sample out multiple times to bake it, wash it, or spin-coat materials onto it,” Franklin says. “Ours is the first where the reality matches the public perception.” John A. Rogers, now a professor of materi...