Pipette Tip Flattened Area Design for Reduced Mounting Force
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Solution Overview
Problem
Conventional pipette tips require high mounting and ejection forces, leading to user strain and potential cumulative trauma disorders, and have production challenges with dimensional accuracy and strength, as well as difficulties in marking and distinguishing different pipette tip types.
Innovation Solution
A pipette tip design featuring an elongated tubular body with flattened areas on the outer circumference, where the wall thickness decreases towards the central region, allowing for elastic or plastic deformation for secure sealing with reduced forces, improved production properties, and enhanced marking capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If conventional thick-walled rigid pipette tips are used, then the pipette tips have sufficient strength and sealing capability, but high mounting forces and ejection forces are required
Solution Approach 1:
The pipette tip features localized thin-walled flattened areas (with wall thickness of 0.5-2 mm, significantly thinner than the surrounding wall) positioned at specific locations where deformation is needed for sealing. The surrounding areas maintain normal wall thickness to preserve overall structural strength. This local differentiation allows the thin-walled areas to deform easily under mounting force to create sealing contact, while the thicker surrounding walls prevent the tip from collapsing or bursting.
Solution Approach 2:
The wall thickness parameter is varied spatially within the pipette tip structure. The flattened areas have reduced wall thickness compared to the cylindrical body, creating regions with different mechanical properties. This parameter change enables the thin-walled areas to undergo elastic or plastic deformation during mounting to achieve sealing, while maintaining sufficient strength in other regions.
2Strength
If conventional thick-walled rigid pipette tips are used, then the pipette tips have sufficient strength, but high ejection forces are required and user strain occurs
Solution Approach 1:
The thin-walled flattened areas are strategically positioned to be the first points of contact with the ejection mechanism. During ejection, force is applied to these localized areas which deform more easily, allowing the pipette tip to be removed from the attachment with lower forces. The thicker surrounding walls maintain structural integrity throughout the ejection process.
Solution Approach 2:
The pipette tip transitions from a rigid static structure to a dynamic structure where the thin-walled flattened areas can deform elastically or plastically during mounting and ejection. This dynamic behavior allows the tip to adapt to the attachment during mounting and to be easily ejected, while maintaining structural integrity when not under load.
3Strength
If conventional uniformly curved pipette tips are used, then the pipette tips have uniform strength, but marking and differentiation of types is difficult
Solution Approach 1:
The flattened areas can be differentiated by various means including color coding, different sizes, or positional variations. This allows visual identification of different pipette tip types (e.g., different volume capacities) without compromising the structural function. The flattened areas serve dual purposes: mechanical deformation for sealing and visual/markable features for identification.
Solution Approach 2:
The introduction of flattened areas creates asymmetry in the otherwise cylindrical symmetric pipette tip. These asymmetric features can be positioned differently or have different characteristics for different tip types, enabling easy visual differentiation and selection of the appropriate tip type for a given application.
4Force
If thin-walled areas are created for reduced mounting force, then mounting force decreases, but the pipette tip may burst during deformation
Solution Approach 1:
The thin-walled flattened areas are localized to specific regions while the surrounding wall maintains normal thickness. This creates a gradient structure where the thin areas deform to enable mounting, but the thicker surrounding walls provide structural support and prevent catastrophic failure or bursting during the deformation process.
Solution Approach 2:
The flattened areas are pre-formed during manufacturing with controlled wall thickness reduction. This preliminary preparation allows the areas to deform in a controlled manner during mounting, absorbing the deformation energy without causing unexpected bursting. The pre-formed geometry ensures predictable deformation behavior.
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 design achieves lower mounting and ejection forces, improved dimensional accuracy and strength, and facilitates marking and differentiation of pipette tip types, reducing the risk of bursting and enhancing ergonomic usability.
Implementation Method 1
the flattened area has in the cross-section through the tubular body (i) a straight profile or (ii) a profile that is less strongly curved than the regions adjoining the flattened area
Implementation Method 2
allowing for elastic or plastic deformation for secure sealing with reduced forces
Data Source
AI summary
A pipette tip made of plastic with an elongated tubular body with a lower opening at the lower end for the passage of liquid and an upper opening at the upper end for clamping onto an attachment of a pipetting device, wherein a seating region for the attachment is present next to the upper opening on the inner circumference of the tubular body, wherein at least one flattened area extending in the axial direction is present next to the upper opening on the outer circumference of the tubular body, the wall thickness of the tubular body gradually decreases in a cross-section through the tubular body, starting from one of the two regions of the tubular body adjoining the flattened area, in the flattened area towards its central region, and the flattened area has in the cross-section through the tubular body a straight or a less strongly curved profile than the adjoining regions.