Pipette Tip Coupler Segmented Sealing and Axial Stop
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Solution Overview
Problem
Current pipette tip coupling systems face issues with air-tight seal reliability due to O-ring compromise, requiring high press forces for sealing and removal, and struggle with precision positioning for smaller holes and volumes, leading to leakage and misalignment problems.
Innovation Solution
A pipette tip coupler and disposable pipette tip combination featuring a plurality of circumferentially disposed elements and a distal elastomeric element, such as an O-ring, providing pre-stress and counter-axial force for improved sealing and easier tip removal, along with an angled squeeze mechanism for enhanced axial force application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conical coupling stud with pre-stressed tip is used, then an air-tight seal is achieved, but high press forces are required causing microfissures and leakage
Solution Approach 1:
The sealing function is divided into multiple segments: a stepped coupling stud with axial stop surfaces for positioning, and a multi-component tip assembly with a distal elastomeric element (O-ring) and proximal elastomeric element. This segmentation allows the sealing action to be distributed across multiple contact points rather than relying on a single pre-stressed conical interface, reducing the force required at any one location while maintaining the air-tight seal.
Solution Approach 2:
A distal elastomeric element (O-ring) is introduced as an intermediary between the stepped coupling stud and the pipette tip. This elastomeric element compresses against the axial stop surface to create the seal, mediating the force transmission and eliminating the need for high press forces to achieve sealing. The elastomeric material naturally conforms to the interface, providing reliable sealing with reduced force requirements.
2Reliability
If high press forces are applied to pre-stress the tip for sealing, then an air-tight seal is created, but correspondingly high forces are required for release
Solution Approach 1:
The stepped coupling stud is designed with an axial stop surface that preliminarily positions the pipette tip at the correct axial location before sealing occurs. This pre-positioning ensures that when the distal elastomeric element compresses against the stop surface, the tip is already correctly aligned, eliminating the need for high forces to achieve both positioning and sealing simultaneously.
Solution Approach 2:
The pipette tip is designed as a disposable component with a simple structure that facilitates easy removal. The tip itself does not require complex retention mechanisms, and the stepped coupling stud with its axial stop surface provides a simple, low-force interface for both sealing and release. The disposable nature allows the tip to be easily discarded after use without requiring significant force for removal.
3Device complexity
If a solitary O-ring configuration is used, then sealing is provided, but seal reliability is compromised when the O-ring becomes compromised
Solution Approach 1:
The sealing system is segmented into multiple functional elements: the stepped coupling stud with axial stop surfaces provides structural support and positioning, the distal elastomeric element (O-ring) provides the primary seal, and the proximal elastomeric element provides additional sealing and cushioning. This segmentation means that if one element is compromised, the others can still maintain the seal, improving overall reliability.
Solution Approach 2:
The proximal elastomeric element acts as a cushioning element that absorbs excess compression forces and provides a backup sealing mechanism. This beforehand cushioning protects the system from the effects of O-ring compromise by providing an alternative sealing path and absorbing the mechanical stress that would otherwise compromise the seal.
4Reliability
If the O-ring is compressed to provide axially directed force for sealing, then an air-tight seal is achieved, but residual force remains after decompression keeping the tip engaged
Solution Approach 1:
The axial stop surface on the stepped coupling stud performs the preliminary action of positioning the pipette tip at the correct axial location before compression occurs. This pre-positioning ensures that when the distal elastomeric element is compressed, the tip is already correctly aligned, and the stop surface provides a hard stop that prevents over-compression and ensures consistent sealing force without residual engagement.
Solution Approach 2:
The axial stop surface acts as an intermediary that controls the compression process. It provides a defined endpoint for the compression stroke, ensuring that the distal elastomeric element is compressed to the correct degree without excessive force. This intermediary control allows the O-ring to decompress fully after sealing, enabling easy tip release without residual engagement forces.
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 configuration enhances the air-tight seal reliability, reduces the force required for sealing and removal, and ensures precise concentricity and straightness, enabling successful targeting of smaller holes and volumes with improved tip alignment and reduced leakage.
Implementation Method 1
the compression of the O-ring results in the deformation of the O ring that in turn provides the axially directed force and air-tight seal against the working surface of the pipette tip
Implementation Method 2
providing a resultant pre-stress force that pre-stresses the pipette tip axially upward
Implementation Method 3
the distal elastomeric element, when compressed against the second working surface, provides a counter axial force to the plurality of elements or segments
Data Source
AI summary
Pipette tip coupler and a disposable pipette tip for a pipette device comprises a stepped coupler shoulder complementary to an axially stepped pipette tip shoulder; a plurality of circumferentially disposed elements or segments carried by the coupler at a location superior to the coupler shoulder; and a distal elastomeric element carried by the coupler at a location distal to the coupler shoulder wherein the plurality of elements or segments have a circumferential, radially translated state that provides an abutment with a first working surface formed in the interior surface of the tip while compressing the distal elastomeric element into sealing abutment with a second working surface formed in the interior surface of the tip and while abutting the proximally facing axial stop surface of the tip with the distally facing axial stop surface of the coupler to define an axial coupling position of the pipette tip on the pipette device.