Pipette Tip Coupler With Leaf Springs for Sealing and Positioning
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Solution Overview
Problem
Current pipette tip coupling systems face issues with air-tight seal reliability due to O-ring compression, requiring high pre-stress forces that can cause microfissures and leakage, and struggle with precise positioning and concentricity, especially in multi-channel systems and smaller holes.
Innovation Solution
A pipette tip coupler and disposable pipette tip combination featuring circumferentially disposed elements and a distal elastomeric element, such as an O-ring, providing axial pre-stress and counter-axial force for improved sealing and easier tip removal, along with an angled squeeze mechanism and flexible leaf springs for enhanced precision and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high pre-stress forces are applied to create an air-tight seal with a conical coupling stud, then sealing is achieved, but microfissures are formed in the pipette tip causing leakage
Solution Approach 1:
The coupling interface is divided into multiple discrete coupling elements arranged circumferentially rather than a single conical stud. Each element applies localized compression to the O-ring, distributing the sealing force and avoiding excessive stress concentration that causes microfissures.
Solution Approach 2:
The coupling mechanism transitions from requiring high axial pre-stress forces to using controlled radial compression through the discrete elements. The O-ring is compressed radially by each element to a controlled degree, achieving sealing without the excessive axial forces that create microfissures.
2Reliability
If high pre-stress forces are applied to create an air-tight seal, then sealing is achieved, but correspondingly high forces are required for release of the pipette tip
Solution Approach 1:
The coupling elements are designed to be individually compressible and releasable. When the pipette tip needs to be removed, the elements can be independently relaxed, reducing the total release force required compared to a single high-stress conical coupling.
Solution Approach 2:
The coupling elements are designed with elastic properties that allow dynamic compression and release. The elements can be compressed during coupling to create the seal, then relaxed during removal, providing a dynamic coupling mechanism that reduces the force required for tip ejection.
3Reliability
If a stepped coupling stud with O-ring is used, then sealing is improved, but the O-ring deformation provides residual force keeping the pipette tip engaged requiring automated external axial counterforce for removal
Solution Approach 1:
Instead of a single large O-ring compressed by a stepped coupling stud, multiple smaller O-rings or sealing elements are used with the discrete coupling elements. This segmentation allows each element to be compressed and released independently, reducing residual forces that prevent tip removal.
Solution Approach 2:
Rather than relying on O-ring compression to provide both sealing and coupling force, the design separates these functions: the discrete elements provide the coupling mechanism while the O-ring provides sealing. This inversion allows the coupling elements to be released without requiring large counterforces to overcome O-ring residual stress.
4Ease of manufacture
If conventional pipette tip coupling is used, then assembly is simple, but precise positioning and concentricity are not achieved especially in multi-channel systems and smaller holes
Solution Approach 1:
The circumferentially disposed discrete coupling elements provide multiple contact points around the pipette tip circumference. This segmentation creates multiple positioning references that work together to achieve precise concentricity and positioning, especially important for multi-channel systems where alignment between channels is critical.
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
The solution ensures a tighter seal, reduces the risk of microfissures, facilitates easier tip removal, and maintains precise concentricity, allowing for accurate targeting and handling of smaller volumes and multiple wells.
Implementation Method 1
a distal elastomeric element in the form of, but not limited to, an O-ring... when compressed against the second interior working surface, provides a counter axial force
Implementation Method 2
providing a resultant pre-stress force which pre-stresses the pipette tip axially upward
Data Source
AI summary
Pipette assembly that includes a pipette device, a pipette tip, and a leaf spring coupling device coupling the tip to the pipette device, the coupling device includes a plurality of circumferentially disposed elements or segments in the form of flexible leaf springs with stabilizer plateaus used to retain a pipette tip to the coupler and prevent the pipette tip from rocking on the coupler and a distal elastomeric element, such as an O-ring, and the pipette tip includes dual complemental working surfaces in the pipette tip to provide precise control of an axial coupled position defined as an axial distance from a distally facing axial stop surface of the pipette tip coupler to the end of the pipette tip that contacts liquid when the pipette tip coupler and disposable pipette tip are in a coupled configuration.