Variable Hollow Microneedle Manufacturing via Parameter Control

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Solution Overview

Problem

Current hollow microneedle manufacturing methods produce standardized products with uniform appearances, limiting their ability to efficiently deliver drugs across various skin regions and handle drugs with different viscosities, as they cannot be easily adjusted for specific skin types, drug viscosities, or administration amounts.

Innovation Solution

A method that adjusts the coating thickness of a viscous material, the diameter of a lifting frame, lifting speed, temperature, and bevel angle to vary the external and internal diameters, length, hardness, and sharpness of hollow microneedles, allowing for customizable microneedle manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If hollow microneedles are manufactured as standardized products with uniform appearances, then manufacturing simplicity is maintained, but the ability to deliver drugs through various skin regions and handle different drug viscosities is limited

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidadaptability to different skin regions and drug viscosities
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent applies parameter changes by systematically varying key geometric parameters of the microneedles including length (50-500 μm), outer diameter (1-50 μm), inner diameter (0.1-10 μm), and wall thickness (0.1-5 μm) to create customized microneedles optimized for different skin types, drug viscosities, and administration requirements, thereby resolving the contradiction between manufacturing simplicity and adaptability

Inventive Principle:
Principle #35Parameter changes

2Object-affected harmful factors

If the diameter of the upper portion of the microneedle is reduced for minimum sharpness, then painless penetration is achieved, but the physical hardness required to pass through the stratum corneum is compromised

Engineering Contradiction:
Improvepain during penetrationVSAvoidphysical hardness
Core Design Contradiction:
Object-affected harmful factorsVSStrength

Solution Approach 1:

The patent applies local quality by creating a non-uniform diameter profile where the upper portion has a smaller diameter (1-50 μm) for sharp, painless penetration while the lower portion has a larger diameter providing structural support and physical hardness, allowing the microneedle to simultaneously achieve both painless penetration and sufficient strength to traverse the stratum corneum

Inventive Principle:
Principle #3Local quality

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

Enables the production of microneedles with varied appearances suitable for different skin regions and drug viscosities, enhancing drug delivery and blood collection efficiency across species, races, and individuals, while maintaining a low manufacturing cost.

Implementation Method 1

coating a solution of a viscous material on a surface of a substrate; bringing the solution of the viscous material into contact with a frame; lifting the substrate, the frame, or the substrate and the frame for the contacted frame and substrate to be spaced apart from each other to thereby manufacture a solid microstructure

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 2

depositing metal on the solid microstructure

Methodology Applied
Scientific EffectPhysical vapor deposition: Physical Vapour Deposition

Implementation Method 3

removing the solid microstructure to obtain a hollow microstructure

Methodology Applied
Scientific EffectDissolution: Solvation

Data Source

PatentEP2594313B1Hollow microneedle having a variable appearance and manufacturing method
Publication Date: 2016.10.19 INCYTO
  • EP2594313B1 patent drawingFigure 1A~2B
  • EP2594313B1 patent drawingFigure 3A~4B
  • EP2594313B1 patent drawingFigure 5A~6B

AI summary

The present invention relates to a method for fabricating a hollow microneedle having a variable appearance. The method makes it possible to vary the length of the microneedle, the outer and inner diameters of the upper and lower parts thereof, the aspect ratio, the sharpness, and the structural bending rate thereof, in accordance with the purposes of the same. Accordingly, the appearance of the hollow microneedles according to the present invention can be varied with flexibility according to various purposes, such as the transferring of medication and the taking of a blood sample, and to various factors, such as the target part for the medication transfer, the depth of the medication transfer, and the amount and viscosity of the medication. Thus, the microneedle can be used as a multi-purpose device for transferring medication.