Self-Folding Microelectrode for Stable Single-Cell Encapsulation

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Solution Overview

Problem

Current microelectrodes face challenges in forming a stable, reliable, and controlled structure for encapsulating single cells and interfacing biological 3D tissue, with limitations in material choice and structural stability, and difficulty in establishing electrical and physical contact.

Innovation Solution

A microelectrode comprising a multilayer sheet with a polymer compound layer and a first compound layer, which self-assembles into a cylindrical form, allowing for a stable interface with biological tissue and enabling efficient signal transduction and stimulation, with the ability to encapsulate single cells and support 3D tissue growth.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional microelectrodes are used for encapsulating single cells and interfacing biological tissue, then the structure formation is limited, but the stability and reliability of the encapsulated structure deteriorates

Engineering Contradiction:
Improvestructure formation capabilityVSAvoidstability of encapsulated structure
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The microelectrode is divided into multiple functional layers including a polymer compound layer, a first compound layer (semiconductive or insulative), and optionally a second compound layer. Each layer serves a specific function: the polymer layer provides structural support and flexibility, the first compound layer enables self-folding through strain, and the second compound layer provides electrical contact. This segmentation allows the device to achieve both versatile structure formation and reliable stable encapsulation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first compound layer is pre-strained during fabrication, storing mechanical energy that drives automatic self-folding when the device is deployed. This preliminary action of pre-straining the layer enables the microelectrode to automatically transform from a flat configuration to a three-dimensional encapsulated structure around biological tissue, ensuring both structural versatility and stability without requiring complex external actuation mechanisms.

Inventive Principle:
Principle #10Preliminary action

2Ease of manufacture

If material choice is limited in conventional microelectrodes, then fabrication is simplified, but structural stability and functionality deteriorates

Engineering Contradiction:
Improvefabrication simplicityVSAvoidstructural stability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The microelectrode employs a composite structure combining a polymer compound layer with a first compound layer (which can be semiconductive or insulative). This composite material approach allows each material to contribute its optimal properties: the polymer provides mechanical flexibility and biocompatibility, while the first compound layer provides either electrical functionality or additional structural stability. This combination achieves both ease of manufacture through established deposition techniques and enhanced structural stability through material synergies.

Inventive Principle:
Principle #40Composite materials

3Device complexity

If electrical contact establishment is difficult in conventional microelectrodes, then device complexity is reduced, but signal transduction efficiency deteriorates

Engineering Contradiction:
Improvecontact establishment complexityVSAvoidsignal transduction efficiency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The first compound layer is designed to automatically self-fold and make contact with the biological tissue through pre-stored strain energy, eliminating the need for complex external actuation mechanisms. The device serves itself by using the inherent mechanical properties of the first compound layer to achieve automatic deployment and electrical contact establishment. This self-service mechanism reduces device complexity while ensuring reliable signal transduction through consistent electrical contact.

Inventive Principle:
Principle #25Self-service

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 self-folding microelectrode provides a reliable structure for interfacing with biological tissues, improving signal transduction and stimulation efficiency while supporting 3D tissue growth, and can be easily implanted with reduced surgical errors.

Implementation Method 1

The multilayer sheet is structured such that, when no external force is applied to the multilayer sheet, the multilayer sheet self-assembly forms a three-dimensional cylindrical form having an internal hollow space

Methodology Applied
Scientific EffectSelf-assembly: Self-Assembly

Implementation Method 2

at least the part of the multilayer sheet extending in the xy-plane or an entire of the multilayer sheet may be subject to internal force(s) induced by strain(s) in the first compound layer

Methodology Applied
Scientific EffectStrain: Deformation

Data Source

PatentEP4561445B1A microelectrode for encapsulating a single cell and/or for being implanted into a biological tissue, a system comprising the microelectrode, and its manufacturing method
Publication Date: 2025.11.19 NTT RESEARCH INC
  • EP4561445B1 patent drawingFigure 1(a)~3(b)
  • EP4561445B1 patent drawingFigure 4(a)~6(b)
  • EP4561445B1 patent drawingFigure 7(a)~8(b)

AI summary

A microelectrode for encapsulating a single cell and/or for being implanted into a biological tissue, wherein the microelectrode comprises a multilayer sheet comprising a polymer compound layer (1, 1A, 1B), and a first compound layer (2, 2A, 2B) being a crystalline monolayer of a first compound or a stack of multiple crystalline monolayers of a first compound, the first compound being semiconductive or electrically insulative, the first compound layer (2, 2A, 2B) being deposited on the polymer compound layer (1, 1A, 1B), wherein the multilayer sheet is structured such that when no external force is applied to the multilayer sheet, the multilayer sheet forms a cylindrical form having an internal hollow space and a longitudinal axis, such that one of said layers forms an outer layer of the cylindrical form and another of said layers forms an inner layer of the cylindrical form.