Heated Pipetting Needle Liquid Volume Heating

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Solution Overview

Problem

Existing pipetting devices struggle to uniformly heat different volumes of liquid to a target temperature, often resulting in insufficient heating of larger volumes or overheating of smaller volumes due to temperature gradients and complex heating control requirements.

Innovation Solution

The method involves sucking in the desired volume of liquid and an additional volume of air, with the air volume selected to ensure the liquid reaches and passes through the heated area with a temperature sensor, ensuring consistent heating across the pipetting needle.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the pipetting needle is heated to a constant target temperature, then the temperature control is simplified, but different liquid volumes cannot be heated uniformly (larger volumes insufficiently heated, smaller volumes overheated)

Engineering Contradiction:
Improveheating control complexityVSAvoidtemperature uniformity
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies local quality by creating a temperature gradient along the pipetting needle, with the heating element positioned at a specific location and the temperature sensor monitoring a localized area. This allows different sections of the needle to serve different functions: the heating zone provides thermal energy while the sensor zone monitors temperature, enabling uniform heating of various liquid volumes without requiring complex adaptive control

Inventive Principle:
Principle #3Local quality

2Temperature

If the pipetting needle is heated more strongly, then small liquid volumes are heated sufficiently, but larger liquid volumes may be overheated

Engineering Contradiction:
Improveheating intensityVSAvoidtemperature uniformity
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent utilizes parameter changes by positioning the temperature sensor to monitor the temperature at the liquid-air interface, which changes depending on the liquid volume. The system adjusts the heating parameters based on the detected temperature at this critical location, ensuring that both small and large volumes reach the target temperature without overheating

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If the liquid volume is small and remains in the suction tip area, then the suction tip may not be heated sufficiently due to temperature gradients

Engineering Contradiction:
Improveliquid volumeVSAvoidheating efficiency
Core Design Contradiction:
Quantity of substanceVSTemperature

Solution Approach 1:

The patent introduces air as an intermediary by allowing the liquid to form a meniscus at the liquid-air interface within the heated zone. This air-liquid interface acts as a thermal mediator, ensuring that even small liquid volumes are exposed to the heated environment and reach the target temperature effectively

Inventive Principle:
Principle #24Intermediary (Mediator)

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 approach achieves more efficient and uniform heating of different volumes of liquid, particularly for small volumes, by ensuring the liquid completely passes through the heated area with a temperature sensor, improving temperature consistency and reducing the complexity of heating control.

Implementation Method 1

temperature-controlled pipetting needles have been in use for a long time, making it possible to adjust the temperature of the liquid to be transferred to the desired value before dispensing it

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

The temperature of the pipetting needle is measured using thermal sensors

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2623202B1Method for heating a volume of liquid in a heated pipetting needle, pipetting device and automated analytical device
Publication Date: 2018.07.18 SIEMENS HEALTHCARE DIAGNOSTICS PRODS
  • EP2623202B1 patent drawingFigure 1
  • EP2623202B1 patent drawingFigure 2

AI summary

The method involves drawing in desired volume of liquid, and drawing in volume of air. Volume of air is selected such that the volume of liquid reaches region of a heated pipetting needle (1) in which a temperature sensor e.g. thermosensor (5), is mounted and completely passes through the region. The pipetting needle has constant intended temperature. The temperature sensor only activates the heating device if the intended temperature is undershot. Drawn-in volume of air and liquid are dispensed. Independent claims are also included for the following: (1) a device for pipetting volume of liquid (2) an analysis instrument for automatically analyzing samples.