Analyte Sensor Electrode Layout for Lower ESR Noise

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing analyte sensors face challenges with high fixed equivalent series resistance (ESR) and variability in measured ESR, leading to reduced signal resolution and prolonged running-in periods during fast transient measurements.

Innovation Solution

The analyte sensor features a substrate with a working electrode and a conductive layer partially covered by a silver comprising layer, which is further protected by a membrane with selective access holes, allowing 20-80% of the conductive layer to remain exposed, reducing ESR variability and enhancing measurement resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a protective coating is applied to isolate most of the electrode to minimize exposed surface area, then selectivity for analyte detection is improved, but the fixed portion of ESR increases significantly

Engineering Contradiction:
Improveanalyte detection selectivityVSAvoidfixed ESR portion
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies local quality by creating different exposure levels for different regions of the electrode. The protective coating covers 20-80% of the electrode surface area, leaving specific regions exposed while others remain covered. This local differentiation allows the sensor to achieve both selectivity (through coated regions) and reduced ESR (through exposed regions), resolving the contradiction between measurement precision and reliability.

Inventive Principle:
Principle #3Local quality

2Measurement precision

If a protective coating minimizes exposed electrode surface area, then background noise from inhomogeneities is reduced, but the variable portion of ESR becomes considerably smaller

Engineering Contradiction:
Improvesignal resolutionVSAvoidESR variability
Core Design Contradiction:
Measurement precisionVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by modifying the exposed surface area parameter to an optimal range (20-80% exposure). This parameter optimization ensures that there is sufficient exposed area to maintain a meaningful variable ESR portion for membrane effect detection, while still providing adequate coverage to reduce background noise. The balanced exposure ratio resolves the contradiction between signal resolution and ESR variability.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If electrode surface area exposed to body fluid is reduced, then membrane effect signal is enhanced, but the measured ESR requires a considerably long running-in period

Engineering Contradiction:
Improvemembrane effect detectionVSAvoidrunning-in period
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies partial action by exposing only a portion (20-80%) of the electrode surface rather than completely covering or completely exposing it. This partial exposure provides a balanced ESR value that is neither too high (which would require long running-in periods) nor too low (which would reduce membrane effect detection capability). The moderate exposed area allows for faster stabilization while maintaining detection sensitivity.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4085829B1Analyte sensor and a method for its producing
Publication Date: 2026.03.18 ROCHE DIABETES CARE GMBH
  • EP4085829B1 patent drawingFigure 1~2B
  • EP4085829B1 patent drawingFigure 3A~3E
  • EP4085829B1 patent drawingFigure 4~5

AI summary

An analyte sensor (110) for determining at least one analyte and a method (140) for producing an analyte sensor (110) are disclosed. The analyte sensor (110) comprises: - a substrate (112); - a working electrode (118) and a conductive layer (122, 124) located on different sites on the substrate (112); - a silver comprising layer (126) partially covering the conductive layer (124); and - a protective layer (128) covering o the silver comprising layer (126) fully apart from at least one area (130) accessible to at least one body fluid comprising the at least one analyte; and o a portion of the conductive layer (124). The analyte sensor (110) as proposed herein significantly reduces noise during measurements. The method (140) which can be performed in an easier manner compared to producing prior art analyte sensors allows considerably higher tolerances during the producing of the analyte sensor (110).