Auto-Pipetting Tip Mandrel With Dual Seals for Low-Force Loading

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Solution Overview

Problem

Existing automated liquid handling and dispensing systems require substantial force to load disposable pipette tips onto pipetting tip mandrels, impacting system size and cost, and necessitate robust actuators to maintain tip attachment.

Innovation Solution

An auto-pipetting apparatus with a dispensing head that uses minimal force to couple and decouple pipette tips through a multi-seal engagement system, employing adjustable seals and a clearance fit between the pipette tip and mandrel, allowing simultaneous capture and sealing of multiple tips with a common actuator.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a tapered fit friction coupling is used to secure pipette tips to mandrels, then reliable tip attachment is achieved, but substantial force is required impacting system size and cost

Engineering Contradiction:

Improvetip attachment reliabilityVSAvoidloading force

Core Design Contradiction:

ReliabilityVSForce

Solution Approach 1:

The sealing mechanism is divided into two separate seals: a first seal (O-ring) that provides radial sealing and friction coupling, and a second seal (flat seal) that provides axial sealing. This segmentation allows each seal to be optimized for its specific function, reducing the overall force required compared to a single seal design that must provide both functions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different sealing surfaces are provided at different locations on the mandrel: a radial sealing surface for the first seal and an axial sealing surface for the second seal. This local differentiation allows the system to achieve reliable attachment with distributed sealing forces rather than concentrated force, reducing peak loading requirements.

Inventive Principle:

Principle #3Local quality

2Reliability

If substantial force is applied to load pipette tips onto mandrels, then adequate tip attachment is achieved, but actuator size and cost increase

Engineering Contradiction:

Improvetip retentionVSAvoidactuator power

Core Design Contradiction:

ReliabilityVSPower

Solution Approach 1:

The sealing function is segmented into two separate seals with distinct orientations and functions. The first seal handles radial sealing and the second seal handles axial sealing, allowing the actuator to apply force more efficiently without requiring excessive power to achieve and maintain tip retention.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The system transitions from a static friction coupling to a dynamic sealing mechanism where the seals are compressed during tip loading and then maintain constant sealing pressure. This dynamic approach allows the actuator to apply force only during the loading phase rather than requiring continuous high power to maintain attachment.

Inventive Principle:

Principle #15Dynamics

3Device complexity

If a single seal design is used, then device simplicity is maintained, but adequate sealing and retention cannot be achieved with minimal force

Engineering Contradiction:

Improvesealing mechanism complexityVSAvoidloading force

Core Design Contradiction:

Device complexityVSForce

Solution Approach 1:

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The two seals are oriented perpendicularly to each other (radial vs. axial orientation), creating an asymmetric sealing arrangement that efficiently distributes sealing forces in different directions. This asymmetric design achieves better sealing performance with lower overall force compared to a symmetric single-seal design.

Inventive Principle:

Principle #4Asymmetry

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 system achieves efficient and cost-effective loading of pipette tips with reduced mechanical stress on the apparatus, enabling a compact design and lower actuator power requirements while maintaining secure tip retention.

Implementation Method 1

a substantially continuous circumferential contact seal with radially impinging contact between the pipetting tip and the at least one pipetting tip mandrel

Methodology Applied

Scientific EffectFriction: Friction

Implementation Method 2

The clearance fit may provide a gap ratio of about 1.02 to 1

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentEP3577468B1Auto-pipetting apparatus and method

Publication Date: 2025.09.17 HIGHRES BIOSOLUTIONS INC

Figure 1
Figure 1A
Figure 2

AI summary

An auto-pipetting apparatus includes a dispensing head with at least one pipetting tip mandrel (200) having an elongated stud body (300) with an insertion end. The at least one pipetting tip mandrel mates with a pipetting tip (399). A first adjustable seal (310A), disposed on the elongated stud body, and a second adjustable seal (310B), disposed on the elongated stud body, seal the pipetting tip mated to the at least one pipetting tip mandrel. The first adjustable seal defines a snub surface. The snub surface effects a substantially continuous circumferential contact seal with radially impinging contact between the pipetting tip and the at least one pipetting tip mandrel. The second adjustable seal is adjustable between a disengaged position and an engaged position and effects a releasable grip and another substantially continuous circumferential contact seal between the pipetting tip and the at least one pipetting tip mandrel around the pipetting tip.