Parylene Pocket Chip Assembly for Neural Implants

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Solution Overview

Problem

Current neural prosthetic technologies face challenges such as fragile electrode shanks, bulky cables, inefficient signal decoding, high signal-to-noise ratio degradation, and complex IC integration, particularly in biocompatibility and miniaturization for biomedical implants like retinal and cochlear prostheses.

Innovation Solution

The development of a parylene-based packaging technology that facilitates the connection and integration of semiconductor chips and components using flexible parylene pockets with pre-metalized connections, allowing for biocompatible and customizable silicon probes with integrated cables, enabling efficient signal transmission and amplification near recording sites.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If traditional metal electrode fabrication and circuitry integration techniques are used, then well controlled metal electrode fabrication and circuitry integration are achieved, but the design becomes brittle and difficult to handle

Engineering Contradiction:
Improvemetal electrode fabrication precisionVSAvoidhandling ease
Core Design Contradiction:
Manufacturing precisionVSEase of operation

Solution Approach 1:

The patent uses flexible printed circuit boards (FPC) instead of traditional rigid metal electrode fabrication. The FPC allows for precise circuitry integration while providing flexibility and ease of handling. The thin film structure enables the circuit board to be bent and configured to match the implant geometry, resolving the contradiction between manufacturing precision and handling ease.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent employs composite materials combining flexible substrates with conductive traces, creating a hybrid structure that integrates the precision of manufactured circuits with the flexibility of soft materials. This composite approach allows precise circuitry integration while maintaining flexibility for surgical handling and implantation.

Inventive Principle:
Principle #40Composite materials

2Reliability

If interconnect cables are used for reliable connections, then reliable interconnect capability is achieved, but the device becomes bulky

Engineering Contradiction:
Improveinterconnect reliabilityVSAvoiddevice volume
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent extracts the cable function by integrating interconnect traces directly into the flexible printed circuit board structure. This eliminates the need for separate bulky interconnect cables while maintaining reliable electrical connections through the flexible circuit board's integrated conductive paths.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent merges the functions of the circuit board and interconnect cables into a single integrated flexible printed circuit structure. The FPC simultaneously serves as the structural support, signal transmission medium, and interconnect interface, eliminating the need for separate cable components and reducing overall device volume.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If electronics are placed far from the recording site, then easier device fabrication is achieved, but signal to noise ratio degrades

Engineering Contradiction:
Improvedevice fabrication easeVSAvoidsignal to noise ratio
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent segments the device into modular components including the flexible printed circuit board with integrated electronics, electrode arrays, and connection interfaces. This segmentation allows electronics to be positioned close to recording sites while maintaining ease of fabrication through modular assembly of standardized components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from planar circuit board layouts to three-dimensional folded and stacked circuit configurations. This dimensional change enables electronics to be positioned in close proximity to deep brain recording sites while maintaining manufacturability through standard FPC fabrication and assembly processes.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentEP2389101B1Pocket-enabled chip assembly for implantable devices
Publication Date: 2020.11.18 CALIFORNIA INST OF TECH
  • EP2389101B1 patent drawingFigure 1
  • EP2389101B1 patent drawingFigure 2
  • EP2389101B1 patent drawingFigure 3

AI summary

Systems and methods for providing biologically compatible pockets or envelopes that can contain chips and other circuit elements and can make electrical connection between those elements and living organisms. The assembled biologically compatible pockets and circuit components can have biomedical applications, such as bioimplantable devices such as retinal, cochlear and cortical prosthesis implants, muscular stimulators, and other uses. In various embodiments, the described technology explains how to make and use pocket systems for dealing with chips having connectors on one or two surfaces, and with other circuit components such as resistors, capacitors, inductors and transistors. Operation of chips encapsulated according to the described technology is demonstrated. Accelerated life testing suggests that the pocket systems described will survive for years at 37 degrees C.