Carbon nanotube electrodes for effective interfacing with retinal tissue

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Developing effective neural interfaces is crucial for understanding neural activity and for creating advanced prosthetic devices.
• Conventional microelectrodes face limitations in signal quality and long-term stability for neural recording and stimulation.

Purpose of the Study:

• To investigate carbon nanotube (CNT) coated microelectrodes as a novel interface material for retinal recording and stimulation.
• To evaluate the performance of CNT electrodes in terms of signal-to-noise ratio and cell-electrode coupling compared to conventional electrodes.

Main Methods:

• Micro-fabrication of 60 CNT-coated microelectrodes (30 µm diameter) with 200 µm spacing.
• Coating electrodes with carbon nanotubes via chemical vapor deposition.
• Recording spontaneous neural activity from neonatal mouse retinas and performing electrical stimulation.

Main Results:

• Consistent recording of neural spikes with high signal-to-noise ratios (up to 75) from mouse retinas.
• Observed gradual increase in spike amplitude over time, indicating improved cell-electrode coupling.
• Successful electrical stimulation using CNT electrodes, demonstrating their dual functionality.

Conclusions:

• CNT-coated microelectrodes exhibit superior performance for retinal interfacing due to their 3D structure and neuro-affinity.
• These findings highlight the potential of CNT electrodes for high-efficacy local stimulation in retinal prosthetic devices.
• Further development could enable micro-scale electrodes for precise neural interfacing.