Expandable Needle Unit for Wider Intradermal Drug Delivery

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Solution Overview

Problem

Conventional drug injection tips are limited by the diameter of the needle holes formed in the skin, resulting in a narrow drug injection range.

Innovation Solution

A needle unit with a cylinder, plunger, and pressing member that expands the needle intervals upon insertion, forming an expansion hole for broader drug distribution, accompanied by a skin treatment device that includes a drug supply and laser application.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If conventional needle insertion method is used, then needle insertion is simple, but drug injection range is narrow

Engineering Contradiction:

Improveneedle insertion simplicityVSAvoiddrug injection range

Core Design Contradiction:

Ease of operationVSArea of stationary object

Solution Approach 1:

The needle unit employs a dynamic expansion mechanism where the pressing member moves relative to the needle holder to spread the needles apart after insertion. This transforms the static needle arrangement into a dynamic configuration that adapts during operation, first inserting with needles close together, then expanding to create a wider injection area for broader drug distribution.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The needle unit divides the injection process into distinct phases: insertion phase with needles in a compact arrangement, and expansion phase where the pressing member separates the needles to form an expansion hole. This segmentation allows the system to optimize for both easy insertion and wide drug distribution by treating these as separate operational stages.

Inventive Principle:

Principle #1Segmentation

2Area of stationary object

If needle intervals are expanded after insertion, then drug injection range is widened, but device complexity increases

Engineering Contradiction:

Improvedrug injection rangeVSAvoidneedle unit structure

Core Design Contradiction:

Area of stationary objectVSDevice complexity

Solution Approach 1:

The pressing member is nested within the needle holder structure, with the needle holder serving as the outer container and the pressing member as an inner component that moves within it. This nesting arrangement allows the expansion mechanism to be integrated into the existing needle unit without requiring separate external components, thereby limiting the increase in overall device complexity.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The pressing member serves multiple functions: it guides the needles during insertion, maintains their initial close spacing for easy insertion, and then expands them to create the injection hole. This multi-functionality reduces the need for additional specialized components, keeping the device complexity manageable while achieving the expanded injection range.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS20260069795A1Needle unit for injecting drug and skin treatment device including the same

Publication Date: 2026.03.12 SEO SUK BAE

AI summary

Provided is a needle unit for injecting a drug. The needle unit includes a cylinder, a plunger that reciprocates in an interior of the cylinder, a plurality of needles that are connected to the plunger and of which at least a partial area is disposed to be selectively exposed to an outside of the cylinder, and a pressing member that is interposed between the plunger and the needles and that spaces apart intervals between the needles exposed to an outside of the plunger. The drug is injected through an expansion hole formed in skin while intervals between tip ends of the needles are spaced apart from each other in a state in which the needles are inserted into the skin.