Reactive-Accelerated-Aging Testing of Thinned Tissue-Engineered Electronic Nerve Interfaces

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Neural implants performance degrades due to tissue responses.
• Reducing implant thickness is a strategy to mitigate tissue response.
• Tissue-engineered-electronic-nerve-interface (TEENI) devices require robust long-term reliability.

Purpose of the Study:

• To reduce the thickness of TEENI devices for improved neural integration.
• To evaluate the long-term reliability of thinned TEENI devices in a simulated harsh environment.

Main Methods:

• Reduced TEENI thread thickness from ~10 μm to ~2.5 μm.
• Incorporated support rails to maintain handleability during assembly.
• Conducted reactive-accelerated-aging (RAA) experiments at 67°C for 6 days (~48 days in tissue).

Main Results:

• Some channels maintained stable impedance, while others showed significant changes.
• Scanning electron microscopy revealed delamination in some high-impedance-change channels.
• Delamination did not consistently correlate with all impedance changes.

Conclusions:

• Thinned TEENI devices show potential for reduced tissue response.
• Variable channel impedance and structural changes highlight the need for further investigation.
• Additional research is required to correlate impedance changes with structural integrity for improved device longevity.