Pipette Tip Grooved Bottom Surface Fluid Control
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Solution Overview
Problem
Conventional pipette tips used in veterinary blood analyzers, such as the VetTest system, often experience spot failures due to inconsistent fluid dispensing, where fluid is drawn up over the outer surface of the tip, leading to imprecise volumetric quantities on test slides, primarily attributed to the design and material of the polypropylene tip.
Innovation Solution
A pipette tip design featuring an enlarged bottom surface with one or more grooves or protrusions, either concentrically or spirally disposed around the central opening, which inhibits fluid from reaching and traveling up the outer surface, thereby minimizing improper volume dispensing by increasing the effective surface area and controlling fluid flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional pipette tip with a small bottom surface is used, then the device is simple and easy to manufacture, but fluid travels up the outer surface causing imprecise volumetric dispensing
Solution Approach 1:
The pipette tip is designed with an enlarged bottom surface and grooves before fluid dispensing occurs. This preliminary structural configuration creates a physical barrier that prevents fluid from traveling up the outer surface, thereby ensuring precise volumetric dispensing from the start of the operation.
Solution Approach 2:
The invention addresses the fluid travel problem by transitioning from a two-dimensional opening to a three-dimensional enlarged bottom surface with grooves. This dimensional expansion creates additional pathways and barriers that effectively block fluid from reaching the outer surface while maintaining precise dispensing control.
2Ease of manufacture
If polypropylene material is used for the pipette tip, then the material is easy to manufacture and cost-effective, but it attracts fluid on the outer surface causing wetting and imprecise volume dispensing
Solution Approach 1:
The pipette tip design applies local quality modification by creating specific structural features (enlarged bottom surface with grooves) at the bottom region where fluid interaction occurs. This localized structural change addresses the wetting problem caused by polypropylene material without requiring a complete material change, maintaining ease of manufacture while improving reliability.
3Reliability
If the bottom surface is enlarged with grooves, then fluid control is improved and wetting is minimized, but the device complexity increases
Solution Approach 1:
The enlarged bottom surface is segmented into multiple grooves that divide the fluid path into separate channels. This segmentation creates distinct flow paths that prevent fluid from coalescing and traveling up the outer surface, thereby improving fluid control accuracy while maintaining a relatively simple overall structure.
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 enhanced pipette tip design ensures more precise fluid dispensing onto chemical reagent test slides or into vials, reducing the occurrence of spot failures and improving the accuracy of fluid volumes, even when made from materials like polypropylene that tend to attract fluids.
Implementation Method 1
it is drawn from the dispensing tip 8 of the pipette 2 due to capillary action, surface tension and gravitational force on the droplet
Implementation Method 2
the propensity of the polypropylene pipette tip 8 to 'wet' or attract fluid on the outer surface of the pipette tip
Data Source
AI summary
A pipette tip includes a main body having an upper end, a lower end and a sidewall extending between the two ends. A bore extends axially through the main body between the upper and lower ends. The lower end has a bottom surface in which is formed a central opening that communicates with the axial bore to allow the passage of fluid therethrough. The bottom surface is formed with at least one groove that may be concentrically disposed or spirally disposed about the central opening. The at least one groove acts to inhibit fluid passing through the central opening from at least partially flowing along the outer surface of the sidewall from the central opening toward the upper end of the main body of the pipette tip.