LTCC Electrochemical Sensor for Flow Rate and Concentration Detection

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Solution Overview

Problem

Existing electrochemical flow sensors face challenges in accurately measuring flow rates and concentrations of electroactive species, particularly in drug delivery systems, where occlusions, leaks, and mechanical failures can go undetected due to limitations in sensor design and bubble trapping.

Innovation Solution

The development of an electrochemical sensor with annular ring electrodes embedded in the walls of a channel, fabricated using Low Temperature Co-fired Ceramic (LTCC) methods, which allows for efficient fluid flow and reduces bubble trapping, enabling measurement of flow rates and concentrations by analyzing the change in electrochemical signals generated by electroactive species.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electrodes are placed in a cylinder-shaped cavity with bottom plate, then electrochemical detection is enabled, but solution flow is blocked and bubble trapping occurs

Engineering Contradiction:
Improvedetection accuracyVSAvoidsolution flow rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent transitions from a 3D cavity structure with bottom plate to a 2D planar electrode array embedded in the channel wall. This dimensional change eliminates the blocking effect while maintaining detection capability, as solution flows parallel to the electrode plane rather than through a confined cavity.

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

Solution Approach 2:

The patent divides the single cavity structure into multiple discrete electrode segments arranged in an array along the channel wall. This segmentation allows solution to flow continuously past each electrode without obstruction, while each electrode independently contributes to the overall detection function.

Inventive Principle:
Principle #1Segmentation

2Reliability

If occlusion sensors are used in drug delivery pumps, then flow monitoring is enabled, but immediate detection of occlusions and mechanical failures is not achieved

Engineering Contradiction:
Improveflow monitoring capabilityVSAvoiddetection response time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements continuous electrochemical measurement by maintaining constant solution flow past the electrode array. This continuous action enables real-time detection of flow changes, immediately signaling occlusions or failures without the time delays inherent in periodic or threshold-based sensing mechanisms.

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent establishes a feedback mechanism where changes in electrochemical signal directly indicate flow status. The continuous monitoring provides immediate feedback about occlusions, leaks, or mechanical failures, enabling prompt system response without delayed detection.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If complex sensor designs are implemented to improve detection accuracy, then measurement precision increases, but device complexity and cost increase

Engineering Contradiction:
Improveflow rate measurement accuracyVSAvoidsensor structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent makes the electrochemical sensor serve multiple functions: it detects flow rate, monitors for occlusions, identifies leaks, and tracks mechanical failures. This multi-functionality eliminates the need for separate sensors for each detection purpose, reducing overall device complexity while maintaining high measurement precision through the electrochemical measurement principle.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

This solution provides immediate detection of altered or no-flow conditions, enabling robust and inexpensive monitoring of flow rates in the nanoliter to microliter range, effectively preventing occlusions, leaks, and mechanical failures in drug delivery systems, while maintaining sensitivity to low volume analytes.

Implementation Method 1

When electroactive species are present in solution, electrodes can be used to measure the flow of electrons to or from the electrode from or to ions in the solution. The electric signal measured will vary by concentration of electroactive specie(s) and by flow rate.

Methodology Applied
Scientific EffectElectrochemical signal generation: Redox Reactions

Data Source

PatentEP3341957B1Measurement of electric signals to detect presence or flow of electroactive species in solution
Publication Date: 2020.08.26 SFC FLUIDICS INC
  • EP3341957B1 patent drawingFigure 1A~1B
  • EP3341957B1 patent drawingFigure 2~3A
  • EP3341957B1 patent drawingFigure 3B~3C

AI summary

An electrochemical sensor may measure the flow of ions and/or electrochemical species in a solution passing the sensor because the electroactive species will continually come into contact with the electrode and an electric signal will be generated by the combination of diffusion and convection bringing the electroactive species to the electrode. The electric signal measured will vary by concentration of ions and/or electrochemical specie(s) and by flow rate. Flow rate may be measured if the concentration of ions and/or electrochemical specie(s) is known; conversely, the concentration of ions and/or electrochemical species may be measured if the flow rate is known. The sensor may also be used to confirm the delivery of a fluid containing ions and/or electrochemical specie(s).