Publication: PEDOT-CNT coated electrodes for stimulation at low voltage amplitudes and low charge densities

In electrode fabrication with common materials, there is always a trade-off between electrode size and impedance. The issue is that a decrease in electrode size results in a higher impedance. And a high impedance is a problem for stimulation, because a high voltage amplitude is needed to efficiently stimulate the cells.

Ramona Samba, Günther Zeck and coworkers (NMI, Reutlingen) now compared two different materials for microelectrodes: Titanium Nitride (TiN) and a conductive polymer composite of poly-3,4-ethylenedioxythiophene (PEDOT) and carbon nanotubes (CNT). They activated spikes in retinal ganglion cells in the flat-mount rat retina through stimulation of the local retinal network and analyzed stimulation efficacy by comparing voltage, current and transferred charge at the stimulation threshold.

They found that:

• With PEDOT-CNT electrodes, a lower stimulation voltage is required to stimulate retinal interneurons compared to TiN electrodes.

• Using PEDOT-CNT electrodes less charge is transferred at stimulation threshold, which is beneficial for electrode stability and the safety of the interfaced neurons.

 

Please find the complete paper published in the Journal of Neuronal Engineering here.

As exclusive distributor for MEAs from the NMI, we are proud to provide the PEDOT-CNT-MEAs. More information can be found here.