Neuromodulation devices such as deep brain stimulators (DBS), spinal cord
stimulators (SCS) and cochlear implants (CIs) use electrodes in contact with
tissue to deliver electrical pulses to targeted cells. In general, the
neuromodulation industry has been evolving towards smaller, less invasive
devices. Improving power efficiency of these devices can reduce battery storage
requirements. Neuromodulation devices can realize significant power savings if
the impedance to charge transfer at the electrode-tissue interface can be
reduced. High electrochemical impedance at the surface of stimulation
microelectrodes results in larger polarization voltages. Decreasing this
polarization voltage response can reduce power required to deliver the current
pulse. One approach to doing this is to reduce the electrochemical impedance at
the electrode surface. Previously we have reported on a novel electrochemically
deposited 60:40% platinum-iridium (Pt-Ir) electrode material that lowered the
electrode impedance by two orders of magnitude or more.
This study compares power consumption of an electrochemically deposited Pt-Ir
stimulating microelectrode to that of standard Pt-Ir probe microelectrode
produced using conventional techniques. Both electrodes were tested using
in-vitro in phosphate buffered saline (PBS) solution and
in-vivo (live rat) models.