Multichannel Pipette Liquid End Assembly Molded Plastic Weight Reduction

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Solution Overview

Problem

Traditional multichannel air-displacement pipettes are often heavy and bulky, leading to ergonomic issues and fatigue during long use, while maintaining accuracy and reliability, and they require labor-intensive manufacturing processes.

Innovation Solution

The use of molded plastic components replaces heavy metal parts in the liquid end assembly of the pipette, including pushrods, pistons, and nozzles, with a compliant interface to ensure channel-to-channel consistency and precision, and a modular design for easy assembly and service.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional metal components (pushrod, pistons, nozzles) are used in multichannel pipettes, then reliability and measurement precision are improved, but weight increases causing operator fatigue

Engineering Contradiction:
Improvemeasurement precisionVSAvoidpipette weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The patent changes the material parameter from metal to molded plastic for pushrods, pistons, and nozzles. This material substitution maintains the functional requirements for reliability and measurement precision while significantly reducing the weight of these components, thereby resolving the contradiction between measurement precision and pipette weight.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite construction by combining molded plastic components with metal only where absolutely necessary (such as the guide shaft), creating a hybrid structure that optimizes the weight-strength-precision tradeoff. This allows the pipette to maintain reliability while reducing overall weight compared to traditional all-metal constructions.

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If precision metal parts are used to ensure accuracy and consistency, then channel-to-channel consistency is improved, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvechannel-to-channel consistencyVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex precision machining of metal parts with molded plastic components that achieve the required manufacturing precision through molding processes. This substitution simplifies the manufacturing process by eliminating labor-intensive metalworking operations while maintaining channel-to-channel consistency through precise mold design and material properties.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the manufacturing approach from metal machining to plastic molding, fundamentally altering the production parameters. This allows for more consistent dimensional control across multiple channels through mold cavity design, reducing the complexity associated with precision metal fabrication while maintaining or improving channel-to-channel consistency.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If heavy metal components are used, then durability and reliability are improved, but ergonomics deteriorate during long usage periods

Engineering Contradiction:
Improvecomponent durabilityVSAvoidergonomics
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent changes the material parameter from dense metal to lighter molded plastic for components like pushrods and pistons. This reduction in component density and overall pipette weight directly improves ergonomics by reducing operator fatigue during extended use, while the molded construction maintains sufficient durability for laboratory applications.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure where only critical load-bearing components retain metal construction for durability, while non-critical components use molded plastic to reduce weight. This selective material distribution maintains necessary durability in key areas while improving overall ergonomics through weight reduction in less critical areas.

Inventive Principle:
Principle #40Composite materials

Data Source

PatentEP2945744B1Liquid end assembly for a multichannel air displacement pipette
Publication Date: 2018.05.02 RAININ INSTRUMENT LLC
  • EP2945744B1 patent drawingFigure 1
  • EP2945744B1 patent drawingFigure 2~3
  • EP2945744B1 patent drawingFigure 4~5

AI summary

A handheld multichannel air displacement pipette is modular in construction and includes compliant joints and molded plastic components in place of various machined metal, glass, and ceramic components found in traditional multichannel pipettes. These improvements are made without sacrificing performance in channel-to-channel consistency, accuracy, and precision. The multichannel pipette is inexpensive to manufacture, lightweight, reliable, and easy to assemble and service.