University of Arkansas scientists have developed a neural probe that demonstrates significantly greater electrical charge storage capacity than all other neural prosthetic devices, making it possible to stimulate nerves and tissues with less damage and sense neural signals with better sensitivity. The probe, made of gold and iridium oxide nanowires grown vertically on a polymer or titanium substrate, has also displayed superior biocompatibility and mechanical strength compared to similar silicon structures.
The researchers repeatedly demonstrated an electrical storage capacity of 48.6 Coulombs per square centimeter. Because storage capacity relates directly to electrical current density needed to stimulate nerves and muscle cells, the probe can transfer charge into biological cells and tissues using less voltage - and less battery power - and thus can operate longer with less tissue and cell damage.
"Our goal is to develop functional systems that can simultaneously stimulate nerves or muscle cells and record physiological changes in the human body," said Hargsoon Yoon, research assistant professor in the College of Engineering and lead researcher on the project. "Our approach can minimize cell damage and even provide higher electrode efficiency than commonly used electrodes."