Conductive Plastic Cuvette Carrier for Accurate Liquid Level Detection

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Solution Overview

Problem

Existing cuvette modules face challenges in precisely measuring small amounts of liquid due to interference from non-conductive plastic materials, leading to inaccurate filling level measurements and potential air pockets, especially when analyzing body fluids.

Innovation Solution

The cuvette module features an electrically conductive plastic cuvette carrier with improved wettability, allowing for reliable filling level determination using electrical sensors and preventing air pockets, while the cuvette itself has lower wettability to maintain distinct liquid droplets for analysis.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a non-conductive plastic material is used for the cuvette carrier, then the material is easy to manufacture and chemically inert, but electrical sensors cannot reliably measure the filling level due to interference signals

Engineering Contradiction:
Improvefilling level measurement accuracyVSAvoidmaterial selection flexibility
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The cuvette carrier is made from a composite material combining plastic with electrically conductive particles (such as carbon black or metal particles). This composite structure maintains the chemical inertness and ease of manufacture of plastic while adding electrical conductivity to enable reliable filling level measurements by electrical sensors without interference signals.

Inventive Principle:
Principle #40Composite materials

2Reliability

If the cuvette carrier has high wettability to prevent air pockets, then liquid distribution is improved, but distinct liquid droplets cannot be maintained for analysis

Engineering Contradiction:
Improveliquid transfer reliabilityVSAvoidliquid droplet distinctness
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system employs different wettability characteristics at different locations: the cuvette carrier (intermediate chamber) has high wettability to ensure complete liquid distribution and prevent air pockets during transfer, while the cuvette has controlled lower wettability to maintain distinct liquid droplets for analysis. This local differentiation of surface properties resolves the contradiction between reliable liquid transfer and precise analysis requirements.

Inventive Principle:
Principle #3Local quality

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

Ensures accurate and precise liquid transfer by minimizing electrical interference and ensuring sufficient liquid in the intermediate chamber before removal, preventing errors and maintaining distinct liquid droplets for analysis.

Implementation Method 1

the cuvette support consists of an electrically conductive plastic material. The cuvette consists of a different material than the cuvette support, the wettability of the cuvette support being higher than the wettability of the cuvette.

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

The level in the intermediate chamber is measured before the predetermined quantity of liquid is removed from the intermediate chamber. The specified amount of liquid can only be removed if there is sufficient liquid in the intermediate chamber.

Methodology Applied
Scientific EffectElectrical resistance measurement: Electrical Resistance

Data Source

PatentEP2729252B1Cuvette module with electrically conductive cuvette holder
Publication Date: 2017.08.09 BEHNK HOLGER
  • EP2729252B1 patent drawingFigure 1~2
  • EP2729252B1 patent drawingFigure 3A~4B
  • EP2729252B1 patent drawingFigure 5~6

AI summary

The invention relates to a cuvette module, comprising a cuvette carrier (14) and a cuvette (19) held by the cuvette carrier (14). An intermediate chamber (18) is formed in the cuvette carrier (14). According to the invention, the cuvette carrier (14) consists of an electrically conductive plastic material. The cuvette (19) consists of a different material than the cuvette carrier (14) and the wettability of the cuvette carrier (14) is greater than the wettability of the cuvette (19). The invention further relates to a method for transferring a predetermined amount of liquid (23) from a transport container to a cuvette (19), in which method a cuvette module according to the invention can be used. The invention makes it easier to check whether the intermediate chamber (18) still contains a sufficient amount of liquid.