Stretchable Encapsulation for Implantable Devices, Limiting Water Permeation

Solution Overview

Problem

Conventional implantable biomedical devices with rigid encapsulation materials fail to conform to mechanical deformations of organs and tissues, leading to insufficient bioelectronic interfacing, delamination, and safety risks due to high water permeability in stretchable encapsulation materials.

Innovation Solution

A stretchable encapsulation method using a biocompatible material, such as parylene C, is applied through pre-stretching and releasing to form a wrinkled surface, enhancing mechanical stretchability and encapsulation properties while maintaining long-term device functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If rigid encapsulation materials (titanium or ceramics) are used, then long-term functionality and stability in body fluid environment is achieved, but mechanical deformations of organs and tissues cannot be accommodated, leading to delamination and insufficient bioelectronic interfacing

Engineering Contradiction:

Improvelong-term functionality and stabilityVSAvoidmechanical deformation accommodation

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent employs flexible encapsulation layers made of elastomeric materials that can deform with organ and tissue movements while maintaining hermetic sealing. These flexible shells accommodate mechanical strains up to 20-100% without delamination, resolving the contradiction between rigidity for stability and flexibility for adaptability.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses composite encapsulation structures combining elastomeric materials with conductive and dielectric layers. This composite approach provides both mechanical flexibility to accommodate deformations and electrical functionality for bioelectronic interfacing, while maintaining long-term stability in body fluid environments.

Inventive Principle:

Principle #40Composite materials

2Adaptability or versatility

If stretchable encapsulation materials (silicone elastomers) are used, then mechanical stretchability and flexibility are improved, but water permeability increases leading to degradation of sensing performance and safety risks

Engineering Contradiction:

Improvemechanical stretchabilityVSAvoidwater permeability

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs flexible encapsulation layers made of elastomeric materials that can deform with organ and tissue movements while maintaining hermetic sealing. These flexible shells accommodate mechanical strains up to 20-100% without delamination, resolving the contradiction between rigidity for stability and flexibility for adaptability.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The patent uses composite encapsulation structures combining elastomeric materials with conductive and dielectric layers. This composite approach provides both mechanical flexibility to accommodate deformations and electrical functionality for bioelectronic interfacing, while maintaining long-term stability in body fluid environments.

Inventive Principle:

Principle #40Composite materials

3Reliability

If conventional rigid encapsulation is used, then hermetic sealing is achieved, but conformal interface with soft tissues and follow their deformations is prevented

Engineering Contradiction:

Improvehermetic sealingVSAvoidconformal interface

Core Design Contradiction:

ReliabilityVSShape

Solution Approach 1:

The patent employs flexible encapsulation layers made of elastomeric materials that can deform with organ and tissue movements while maintaining hermetic sealing. These flexible shells accommodate mechanical strains up to 20-100% without delamination, resolving the contradiction between rigidity for stability and flexibility for adaptability.

Inventive Principle:

Principle #30Flexible shells and thin films

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method achieves over 60% uniaxial strain without fracturing, reduces water vapor transmission rate, and maintains stable capacitance readings, demonstrating effective encapsulation and sensitivity for implantable devices in body fluid environments.

Implementation Method 1

The outer film layer is configured to flex or stretch and including a biocompatible material... the outer film layer is configured to be stretched to up to about 60-80% uniaxial strain without fracturing

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 2

Commonly used stretchable encapsulation materials, such as silicone elastomers, have relatively high water permeability... the at least one encapsulation layer includes a first elastomeric layer positioned on a first side of the plurality of electrodes and a second elastomeric layer positioned on a second side of the plurality of electrodes opposite the first side

Methodology Applied

Scientific EffectPermeation: Permeation

Data Source

PatentUS20250213193A1Stretchable encapsulation for implantable biomedical devices

Publication Date: 2025.07.03 UNIV OF SOUTHERN CALIFORNIA

AI summary

An implantable device configured to be used within a human body that includes a plurality of electrodes positioned between at least one encapsulation layer and an outer film layer. The outer film layer is configured to flex or stretch and including a biocompatible material.