Mechanically-Flexible Diamond Electrodes for Implantable Sensors

Conductive diamond has potential advantages for chemical and electrical recording in neural systems because of chemical stability, higher signal-to-noise ratio and reduced biological fouling relative to traditional electrode materials. However, to confirm this, implantable diamond electrodes must be designed to withstand movements of a live, freely-behaving animal. This presentation focuses on two strategies to make mechanically flexible electrode assemblies with diamond as the active electrode component. In one strategy, we have developed a diamond patterning process compatible with polymer micromachining in order to create a diamond microelectrode assembly on a flexible, low-temperature polymer support. We have also been developing “flexible” diamond hook electrodes for nerve electrical recording by selectively growing diamond on the ends of masked rhenium alloy wires. The rhenium alloy substrates remain significantly more ductile than traditional diamond growth substrates. Benchtop and in vitro/in vivo characterization of these electrode structures is ongoing.