# Development and Translation of novel SiC encapsulation thin film for chronic auditory nerve implant electrodes

> **NIH NIH R44** · BLACKROCK MICROSYSTEMS · 2020 · $749,625

## Abstract

Abstract
A range of neurological diseases are now being researched or treated using fully implantable
electronic systems to either record or modulate brain activity in humans. These implants are
currently being protected using polymer coatings that envelop the implant and help keep body
fluids away from the sensitive electronics. Brain implants with complex three-dimensional
geometries, like the Utah Electrode Array (UEA) provide a challenge for current encapsulation
techniques. Parylene has been the gold standard for encapsulation of neural and biomedical
implants in general due to its well-suited combination of biocompatibility, electrical properties and
chemical inertness. However recording capabilities of long-term neural implants (>6 months)
encapsulated with Parylene show signs of degradation. To address this problem, we propose to
develop and evaluate performance and biocompatibility/safety of a new Silicon Carbide (SiC)
based encapsulation designed to extend the long term stability and implantable lifetime for a high
density Utah Slant Electrode Array (HD-USEA) in line with lifetime expectations for conventional
cochlea implant electrodes. The HD-USEA is used as penetrating auditory nerve electrode in a
new type of intracranial auditory prosthesis that targets the auditory nerve en route to the
brainstem in order to substantially improve hearing performance over the current standard of care,
the cochlear implant (CI) (NIH 1UG3NS107688-01).
SiC has been studied in the past as encapsulation and electrode material due to its outstanding
inherent material properties. This encapsulation layer, novel to biomedical field, will retain all the
advantages of Parylene while utilizing vastly superior dielectric properties of silicon carbide layer
to create a much longer lasting and more electrically stable biomedical implants. This layer
encapsulation scheme may be seamlessly incorporated into our existing fabrication process flow
for our flagship product, the UEA. This encapsulation will work on different surfaces (metal,
semiconductor, polymer, ceramic) and on devices with integrated wireless components making it
ideal for coating any complex medical device intended for long term implant. Our preliminary
results with silicon carbide coated UEA are very promising in support of the proposed work. We
have shown that silicon carbide yields more stable leakage current, and stable impedance (with
<5% change). This superior performance of suggests its potential usefulness for chronic implants
with complex surface geometries.

## Key facts

- **NIH application ID:** 10220177
- **Project number:** 4R44DC018261-02
- **Recipient organization:** BLACKROCK MICROSYSTEMS
- **Principal Investigator:** Stuart F Cogan
- **Activity code:** R44 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $749,625
- **Award type:** 4N
- **Project period:** 2019-08-10 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10220177

## Citation

> US National Institutes of Health, RePORTER application 10220177, Development and Translation of novel SiC encapsulation thin film for chronic auditory nerve implant electrodes (4R44DC018261-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10220177. Licensed CC0.

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