Pipette Tip Projections Prevent Residual Droplet Adhesion
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Solution Overview
Problem
Existing pipette tips fail to reliably prevent residual droplets from adhering to the injection opening after blood injection, leading to contamination and errors in chemical component measurements during centrifugal separation.
Innovation Solution
A pipette tip design with projections around the ejection opening that protrude in the ejection direction, ensuring the residual droplet does not adhere to the injection opening by maintaining a specific distance and length to prevent contact, thereby preventing contamination and ensuring accurate measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a tubular cover is provided to cover the entire outer periphery of the distal end portion, then blood splashing to positions outside the sample container is prevented, but residual droplets adhere to the cover and may transfer to the injection opening
Solution Approach 1:
The cover is divided into a main body portion and a separate projection portion. The projection portion extends in the ejection direction and is positioned to prevent residual droplets from contacting the injection opening, while the main body portion prevents blood splashing. This segmentation allows each part to address specific harmful effects independently.
Solution Approach 2:
A projection portion is added that extends in the ejection direction (longitudinal dimension), creating a new spatial dimension for protection. This projection creates a physical barrier that prevents residual droplets from traveling along the ejection path to the injection opening, addressing a problem that a simple tubular cover cannot solve.
2Ease of manufacture
If the pipette tip structure is simplified without additional protective features, then manufacturing is easier, but residual droplets adhere to the injection opening causing contamination
Solution Approach 1:
The projection portion is pre-formed as an integrated feature of the distal end portion during the molding process. This preliminary structural provision ensures that when the pipette tip is used, the projection is already in position to prevent residual droplet adhesion to the injection opening, eliminating the need for additional protective components or post-assembly steps.
3Reliability
If a projection is added to prevent residual droplet adhesion, then injection opening contamination is prevented, but device complexity increases
Solution Approach 1:
The projection portion is merged with the distal end portion as a single integrated structure formed in one molding process. This merging eliminates the need for separate components, assemblies, or fastening mechanisms, thereby preventing residual droplet adhesion while minimizing the increase in device complexity.
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 pipette tip effectively prevents residual droplets from adhering to the injection opening, reducing contamination risks and ensuring the reliability of chemical component measurements during centrifugal separation.
Implementation Method 1
after liquid has been ejected from a thin tube, such as a pipette tip, due to surface tension acting on the ejection opening, a residual droplet, which is not dropped, protrudes from the ejection opening in the ejection direction
Implementation Method 2
The blood is separated into a blood cell component and a blood plasma component by spinning the sample container in a centrifuge
Data Source
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AI summary
Provided is a pipette tip and a liquid injection method that can reliably prevent a residual droplet at an ejection opening from adhering to an injection opening of a sample container. A pipette tip includes a body and projections 15. In the body, a flow passage in which liquid from the syringe flows and an ejection opening 20A that ejects the liquid, which has flowed through the flow passage, to the outside are formed. The ejection opening 20A is formed in a distal end portion 20. The projections 15 are provided on the distal end portion 20 and protrude from a region around the ejection opening in the ejection direction ED of liquid. The projections 15 are partially disposed around the central axis CA of the body. Even in a case where a residual droplet 24 adheres to the ejection opening 20A, the residual droplet does not adhere to an injection opening of a sample container, because the projections 15 guard a region around the residual droplet 24.