Dynamic Softening Electrochemical Sensors for Comfortable Skin Insertion

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Solution Overview

Problem

Current medical devices for continuous monitoring of physiological properties like blood glucose concentration are limited by their invasive nature, discomfort, and inability to provide real-time, continuous, and reliable measurements of analytes in interstitial fluid.

Innovation Solution

A flexible substrate-based sensor system with electrodes that can penetrate the skin to detect analytes electrochemically, featuring a permeable material that softens upon insertion, allowing for comfortable, long-term monitoring with wireless communication capabilities.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid permeable material is used for the elongate portion to enable skin piercing, then the sensor can penetrate the skin surface effectively, but it causes user discomfort and potential tissue damage during prolonged wear

Engineering Contradiction:
Improveskin piercing capabilityVSAvoiduser discomfort
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The elongate portion is designed with dynamic mechanical properties that change over time: initially rigid to facilitate skin penetration, then progressively softer to minimize discomfort. This temporal transformation of material properties resolves the contradiction between needing strength for insertion and softness for comfortable wear.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The material parameters of the elongate portion are designed to change from a rigid state during insertion to a softer state during wear. This parameter transformation allows the same material to satisfy both the skin-piercing requirement and the comfort requirement at different time points.

Inventive Principle:
Principle #35Parameter changes

2Strength

If the elongate portion maintains high rigidity for effective skin piercing, then insertion is successful, but it prevents comfortable long-term wear and movement with the skin

Engineering Contradiction:
Improveinsertion effectivenessVSAvoidwear duration
Core Design Contradiction:
StrengthVSDuration of action of moving object

Solution Approach 1:

The elongate portion transitions from a rigid insertion state to a flexible wear state, enabling both effective initial insertion and prolonged comfortable wear. The material's mechanical properties are designed to evolve temporally, allowing the sensor to adapt to different functional requirements over time.

Inventive Principle:
Principle #15Dynamics

3Ease of operation

If a flexible substrate is used for comfort and conformability, then user comfort is improved, but it reduces the structural integrity needed for reliable electrochemical detection

Engineering Contradiction:
Improveuser comfortVSAvoiddetection reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The substrate exhibits spatially varying mechanical properties: flexible in regions that contact skin for comfort, and more rigid in regions housing the electrochemical sensors for detection reliability. This local differentiation of material properties allows both comfort and reliability requirements to be satisfied simultaneously in different locations.

Inventive Principle:
Principle #3Local quality

4Reliability

If the sensor penetrates deeply to access interstitial fluid for continuous monitoring, then measurement reliability is improved, but it increases insertion complexity and potential tissue trauma

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidinsertion complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The elongate portion's rigidity decreases over time after insertion, transforming from a rigid insertion tool to a soft implanted sensor. This temporal softening simplifies the insertion process while maintaining the ability to reach the required depth for reliable interstitial fluid measurement.

Inventive Principle:
Principle #15Dynamics

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

Enables real-time, continuous, and comfortable monitoring of analytes in interstitial fluid, minimizing user discomfort and providing reliable data for physiological property measurements.

Implementation Method 1

the first electrode and second electrode are configured to detect the analyte electrochemically

Methodology Applied
Scientific EffectElectrochemical detection: Redox Reactions

Implementation Method 2

the elongate portion comprises a permeable material configured with an initial rigidity for piercing a skin surface, and arranged to soften when the elongate portion is subsequently extended beneath the skin surface

Methodology Applied
Scientific EffectMaterial softening: Absorption (physical)

Data Source

PatentEP3258848B1Electrochemical sensor for a bandage type of continuous glucose monitoring system
Publication Date: 2021.05.12 VERILY LIFE SCIENCES LLC
  • EP3258848B1 patent drawingFigure 1A~1B
  • EP3258848B1 patent drawingFigure 2A~2D
  • EP3258848B1 patent drawingFigure 3

AI summary

An electrochemical sensor of a flexible, body-mountable analyte sensing device is provided. The electrochemical sensor is disposed on a flexible sensor probe that is configured to penetrate the skin such that the electrochemical sensor disposed on the sensor probe can detect an analyte in interstitial fluid. The electrochemical sensor is made sensitive to the analyte by disposing a substance that selectively binds to reacts with, catalyzes a reaction of, or otherwise selectively interacts with the analyte. The substance is localized by crosslinking on the surface of an electrode and/or by being disposed in a polymer layer disposed on the electrode. The polymer layer can be a hydrogel. Further, a hydrogel layer can be formed on the sensor probe to protect elements of the sensor probe and to increase the biocompatibility of the sensor probe.