Microneedle Array With Non-Uniform Sheet Thickness

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Solution Overview

Problem

Existing microneedle arrays face challenges in withstanding puncture impact during drug administration, as they often suffer damage due to the brittleness of water-soluble polymer materials used, which limits their reproducibility and flexibility, especially when trying to penetrate the skin while maintaining strength and flexibility.

Innovation Solution

A microneedle array design where the end portion has a thinner average film thickness compared to the central portion, with a curved surface shape and a controlled deformation height, allowing for enhanced puncture resistance and flexibility by distributing stress effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the sheet thickness is increased to withstand puncture impact, then the strength is improved, but the amount of polymer material increases and drying time extends

Engineering Contradiction:
ImprovestrengthVSAvoiddrying time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The sheet employs non-uniform thickness distribution with a first region (central area) having greater thickness than a second region (peripheral area). This local quality variation allows the central portion to withstand puncture impact while reducing overall material usage and drying time compared to a uniformly thick sheet.

Inventive Principle:
Principle #3Local quality

2Productivity

If the sheet thickness is reduced to decrease material amount and drying time, then productivity is improved, but the sheet cannot withstand puncture impact

Engineering Contradiction:
ImproveproductivityVSAvoidstrength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

By concentrating thickness in the central first region where puncture force is applied, the sheet achieves sufficient local strength for puncture resistance while maintaining reduced overall thickness for faster drying and higher productivity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The sheet is pre-formed with non-uniform thickness distribution before puncture occurs, preparing the structural strength exactly where needed in advance, allowing thin overall design to still withstand impact forces.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If water-soluble polymer material is used for the sheet, then biocompatibility is improved, but brittleness increases reducing reliability

Engineering Contradiction:
ImprovebiocompatibilityVSAvoidreliability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The non-uniform thickness design compensates for the inherent brittleness of water-soluble polymers by concentrating material where stress occurs during puncture, maintaining reliability while preserving biocompatibility.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3466478B1Microneedle array
Publication Date: 2020.08.26 FUJIFILM CORP
  • EP3466478B1 patent drawingFigure 1
  • EP3466478B1 patent drawingFigure 2A~2C
  • EP3466478B1 patent drawingFigure 3~5

AI summary

An object of the present invention is to provide a microneedle array which has strength of withstanding the impact at the time of puncture. According to the present invention, provided is a microneedle array including: a sheet; and a plurality of needles which are present on an upper surface of the sheet, in which the needles contain a water-soluble polymer, the sheet contains a water-soluble polymer, the sheet has a central portion, which is a region where the plurality of needles are formed, and an end portion, and an average film thickness of the end portion is smaller than an average film thickness of the central portion.