A research team from the National Institute of Standards and Technology (NIST) has come up with a way to build safe, nontoxic gold wires onto flexible, thin plastic film. Their demonstration potentially opens the way for wearable electronic devices that monitor health.
"Overall this could be a major step in wearable sensor research," said NIST biomedical engineer Darwin Reyes-Hernandez.
Reyes-Hernandez was exploring a porous polyester membrane to see if its tiny holes could make it useful for separating different fluid components. He patterned some gold electrodes onto the membrane to create a simple device that would help with separations.
By complete chance, he twisted the plastic a few times and noticed the electrodes which covered numerous pores as they crisscrossed the surface still conducted electricity. This wasn't the case with nonporous membranes.
"Apparently the pores keep the gold from cracking as dramatically as usual," Reyes-Hernandez explained. "The cracks are so small that the gold still conducts well after bending."
According to the researchers, the electrodes show even higher conductivity than their counterparts on rigid surfaces – an unexpected benefit which cannot yet be explained.
"This thin membrane could fit into very small places," Reyes-Hernandez concluded. "Its flexibility and high conductivity make it a very special material."