Objective:

To develop a multi-layer brain-mimicking phantom that replicates the dura and pia mater dimpling and rupture characteristics during neural interface insertions.

Approach:

• Phantom Composition: The phantom consists of a 0.5% (w/v) agarose cortex layer, a 1.01% (w/v) agarose pia mater layer, and a pre-stretched polyvinyl chloride (PVC) dura mater layer.
• Testing Methodology: Rupture force and dimpling depth were quantified using a cantilever-beam force measurement system across microwires of varying diameters, materials, and tip geometries.

Key Findings:

• The phantom test results aligned with in vivo data from Sprague–Dawley rats.
• Phantom insertion trials exhibited significantly lower variability compared to in vivo tests.

Interpretation:

The multi-layer phantom serves as a repeatable, low-cost screening platform for novel electrode designs, allowing for customizable testing to accelerate neural implant development.

Limitations:

• The phantom may not fully replicate all biological responses of living tissue.
• Further validation is needed to ensure the phantom's applicability across different species or devices.

Conclusion:

The developed phantom offers a promising alternative for early-stage neural interface testing, potentially reducing the need for animal trials.