Microneedle Arrays Fabricated by Progressive Stamping

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Solution Overview

Problem

Current methods for fabricating microneedle arrays are costly and time-consuming, making them expensive and challenging to produce with precise microneedle formation and placement for effective transdermal drug delivery and fluid transfer through the skin.

Innovation Solution

A method involving progressive stamping of a sheet blank with a series of dies to form deep drawn microneedle arrays, where the microneedles are formed from a base member with a flexible wall that can be biased to create a vacuum for fluid transfer, and the microneedle arrays are designed to pierce the skin with precision and reproducibility.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional microneedle fabrication methods are used, then microneedle arrays can be produced, but the process is time-consuming and costly

Engineering Contradiction:

Improvemicroneedle formation precisionVSAvoidfabrication speed

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The microneedle arrays are pre-formed on the applicator device during manufacturing, allowing for precise formation of multiple microneedles in predetermined patterns before use. This preliminary action eliminates the need for complex real-time fabrication during application, achieving both precision and efficiency

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If microneedle arrays are fabricated with high precision, then effective transdermal delivery is achieved, but the fabrication cost increases

Engineering Contradiction:

Improvemicroneedle placement precisionVSAvoidfabrication cost

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The fabrication process divides the formation of multiple microneedles into sequential stamping operations using progressive dies. Each die forms a portion of the microneedle array, allowing for precise placement while breaking down the complex fabrication into simpler, more cost-effective steps

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Complex chemical or biological fabrication methods are replaced with mechanical stamping processes. The progressive die stamping system uses mechanical force to displace material and form microneedles, providing precise placement at lower cost compared to alternative high-precision fabrication methods

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Quantity of substance

If the flexible wall is allowed to expand fully, then maximum fluid transfer volume is achieved, but the device structure becomes less stable

Engineering Contradiction:

Improvefluid transfer volumeVSAvoiddevice structural stability

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

A flexible wall made of elastomeric material is used to create a chamber that can expand and contract. This flexible membrane allows the chamber volume to increase for maximum fluid transfer while the surrounding rigid structure maintains overall device stability during expansion

Inventive Principle:

Principle #30Flexible shells and thin films

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

This approach results in cost-effective, reproducible, and precisely formed microneedle arrays that enable efficient transdermal delivery of drugs and fluid sampling with reduced pain and improved patient compliance, overcoming the limitations of existing fabrication methods.

Implementation Method 1

a flexible wall that is movable to a depressed configuration enclosing a second volume in the chamber less than the first volume

Methodology Applied

Scientific EffectVacuum: Vacuum

Implementation Method 2

configured to apply a suction force to the treatment area to draw fluid into contact with the sensor component

Methodology Applied

Scientific EffectSuction: Suction

Data Source

PatentUS10524730B2Medical devices with microneedle arrays and methods for operating such medical devices

Publication Date: 2020.01.07 MEDTRONIC MINIMED INC

AI summary

Microneedle arrays, methods for fabricating microneedle arrays, medical devices, and methods for operating medical devices are provided. A method for fabricating a microneedle array includes providing a sheet blank of material. Further, the method includes stamping the sheet blank of material with a progression of dies, wherein the material is displaced into the microneedle array. A medical device includes a microneedle array, a base member having a first surface supporting the microneedle array and a second surface, and a flexible wall enclosing a chamber between the flexible wall and the second surface of the base member. The flexible wall is biased toward an extended configuration enclosing a first volume in the chamber. Further, the flexible wall is movable to a depressed configuration enclosing a second volume in the chamber less than the first volume.