Wearable health monitors are already commonly used for a variety of applications, such as measuring fitness levels and heart rates, but doctors have an eye toward using them for the loftier purpose of personalized medicine.
Wearable devices can provide real-time information on an individual’s bodily processes, which can help doctors detect disease earlier than otherwise possible and allow them to tailor solutions for a patient’s specific needs.
The problem with the development of this wearable sensor technology to date has been how to build the devices so they are both reliable and safe, which requires a blend of durable and non-toxic materials that are comfortable to wear as well as reliable. The recent discovery by NIST involves embedding gold electrodes into a porous, flexible plastic membrane, which could be a major step toward solving that conundrum.
NIST biomedical engineer, Darwin Reyes-Hernandez, who works in the field of microfluidics, made the discovery when working on a commercially viable porous polyester membrane. While trying to determine whether microscopic holes in the membrane would make it useful for separating different fluid components, he patterned some gold electrodes onto the membrane in an effort to help in the separation process.
Reyes-Hernandez noticed the electrodes still conducted electricity as he twisted the plastic, something not present in nonporous membranes. With further testing, he realized the porous membrane’s electrodes actually had even higher conductivity than similar ones on rigid surface–an unexpected benefit he has yet to explain.
“Gold has been used to make wires that run across plastic surfaces,” said Reyes-Hernandez. “But until now the plastic has needed to be fairly rigid. You wouldn’t want it attached to you; it would be uncomfortable.”
But the combination of gold electrodes, which don’t corrode and are nontoxic, embedded in flexible plastic could be ideal for wearable technology and the field of personalized medicine.
“This thin membrane could fit into very small places,” Reyes-Hernandez added. “And its flexibility and high conductivity could make it a very special material; almost one of a kind.”
With this initial discovery under his belt, Reyes-Hernandez says the next step is to test the membrane for any changes in conductivity over long-term use through many bends and twists, and then build some kind of sensor unit using the electrode-coated membrane to explore how it would work in a real-world application.