Daily Archives: October 4, 2019

Electrified Tattoos and Personalized Biosensors

Electrical engineers at Duke University have devised a fully print-in-place technique for electronics that is gentle enough to work on delicate surfaces including paper and human skin. The advance could enable technologies such as high-adhesion, embedded electronic tattoos and bandages tricked out with patient-specific biosensors.

Two electronically active leads directly printed along the underside of Duke graduate student Nick Williams’s pinky successfully light up an LED when a voltage is applied

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,” said Aaron Franklin, Associate Professor at Duke.

“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 said. “Ours is the first where the reality matches the public perception.

The concept of so-called electronic tattoos were first developed in the late 2000s at the University of Illinois by John A. Rogers, who is now Professor of Materials Science and Engineering at Northwestern University. Rather than a true tattoo that is injected permanently into the skin, Rogers’s electronic tattoos are thin, flexible patches of rubber that contain equally flexible electrical components.

The thin film sticks to skin much like a temporary tattoo, and early versions of the flexible electronics were made to contain heart and brain activity monitors and muscle stimulators. While these types of devices are on their way to commercialization and large-scale manufacturing, there are some arenas in which they’re not well suited, such as when direct modification of a surface by adding custom electronics is needed. “For direct or additive printing to ever really be useful, you’re going to need to be able to print the entirety of whatever you’re printing in one step,” said Franklin. “Some of the more exotic applications include intimately connected electronic tattoos that could be used for biological tagging or unique detection mechanisms, rapid prototyping for on-the-fly custom electronics, and paper-based diagnostics that could be integrated readily into customized bandages.”

The techniques are described in a series of papers published in the journal Nanoscale and in the journal ACS Nano.

Source: https://pratt.duke.edu/