Microneedle Applicator With Conical Spring And Piston Plate

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Solution Overview

Problem

Conventional microneedle applicators are large in size and weight, making them inconvenient for users who need to wear them for extended periods to transfer active ingredients into the body, and they can be cumbersome and frightening due to their size.

Innovation Solution

An applicator design featuring a piston plate with a non-linear coil spring that allows for a compact structure by eliminating the need for a shaft and utilizing a conical coil spring to reduce height and weight, with a release mechanism that enables the piston plate to move into position for skin puncture without external assistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional microneedle applicator design with a shaft is used, then the applicator can effectively transfer active ingredients into the body, but the applicator becomes large in size and heavy in weight

Engineering Contradiction:
Improveeffective transfer of active ingredientsVSAvoidweight of applicator
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The invention extracts and eliminates the shaft component from the applicator design. By removing this unnecessary structural element, the applicator achieves significant weight reduction and size miniaturization while maintaining the core functionality of microneedle deployment and active ingredient transfer through the piston plate mechanism

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The piston plate is designed to serve multiple functions: it acts as both the structural component that holds the microneedles and the moving element that delivers the puncture force. This multi-functionality eliminates the need for separate shaft and piston components, reducing overall applicator weight while maintaining reliability

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Force

If a conventional cylindrical coil spring is used, then the spring can provide sufficient biasing force, but the applicator height increases

Engineering Contradiction:
Improvebiasing force of springVSAvoidheight of applicator
Core Design Contradiction:
ForceVSLength of moving object

Solution Approach 1:

The invention employs a conical coil spring instead of a conventional cylindrical spring. The conical geometry allows the spring to provide sufficient biasing force while occupying less axial space, thereby reducing the overall height of the applicator while maintaining the necessary mechanical force for microneedle deployment

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Ease of operation

If the applicator size is reduced, then the applicator becomes more convenient to wear and carry, but the structural complexity increases

Engineering Contradiction:
Improveconvenience of wearing and carryingVSAvoidstructural complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The invention merges multiple components into integrated structures: the piston plate combines microneedle mounting, piston functionality, and locking mechanism elements; the casing integrates the spring housing and release mechanism. This merging reduces the number of separate parts, simplifying the overall structure despite the reduced size

Inventive Principle:
Principle #5Merging (Combining)

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 a significant reduction in size and weight, allowing for easier handling and reduced fear, while ensuring effective transfer of active ingredients and minimizing the risk of microneedles coming off or breaking during use.

Implementation Method 1

a non-linear coil spring that is arranged on another main surface side of the piston plate and exerts an elastic force on the piston plate

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP2937111B1applicator
Publication Date: 2020.03.18 HISAMITSU PHARM CO INC
  • EP2937111B1 patent drawingFigure 1
  • EP2937111B1 patent drawingFigure 2
  • EP2937111B1 patent drawingFigure 3

AI summary

To provide an applicator that can achieve a further reduction in size and weight. An applicator A1 includes a casing 10, a piston plate 20, a microneedle array 30, a conical coil spring 40, and a release member 50. The casing 10 includes: a tubular main body part 12 that houses therein the piston plate 20 and the conical coil spring 40; and a cover part 14, the cover part 14 and the piston plate 20 sandwiching the conical coil spring 40 therebetween. The main body part 12 includes interior inner walls 12b1 to 12b4 that lock the piston plate 20 with the casing 10 by means of projections 20c1 to 20c4. The main body part 12 includes groove parts G1 to G4 that extend in the top-bottom direction. The piston plate 20 is guided in the axial direction of the main body part 12 by the groove parts G1 to G4. If a locked state of the piston plate 20 is released by the release member 50, the piston plate 20 is moved, by the biasing force of the conical coil spring 40, along the groove parts Gl to G4 inside of the main body part 12 to reach a position for action on a skin.