Tapered Electroformed Needle with Surface Projections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional thin needles, including those formed by electroforming, still cause pain during puncture due to external peripheral surface contact with pain spots, and their manufacturing is time-consuming and costly due to accuracy and rust issues.
Innovation Solution
A tapered needle with projections formed by electroforming on its external peripheral surface, using particles like silicon carbide, sapphire, or diamond ceramics, which reduces pain by minimizing contact with pain spots and lowers manufacturing costs through a precise electroforming method involving multiple electrolyte steps and masking agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the external diameter of the needle is reduced to minimize pain, then the pain is reduced, but the flow resistance during injection increases
Solution Approach 1:
The needle is divided into two distinct portions: a proximal portion with a larger diameter to reduce flow resistance, and a distal portion with a smaller diameter to minimize pain during puncture. This segmentation allows each portion to optimize its function independently.
Solution Approach 2:
Different portions of the needle have different diameters tailored to their specific functions. The proximal portion has a larger diameter for efficient fluid flow, while the distal portion has a smaller diameter for reduced pain, creating local quality variations along the needle length.
2Ease of manufacture
If a tapered needle is formed by rolling up a plate material, then the needle can be manufactured, but the joined portion requires high processing accuracy and increases manufacturing time and cost
Solution Approach 1:
The mechanical rolling and joining process is replaced with an electroforming process. The tapered needle is formed by electrodepositing metal onto a tapered mandrel, eliminating the need for mechanical rolling, joining, and associated high-precision processing steps.
3Ease of manufacture
If a tapered needle is formed by elongating a cylindrical member, then the needle can be manufactured, but rust occurs on the internal peripheral surface and processing becomes difficult
Solution Approach 1:
The mechanical elongation process is replaced with electroforming. The needle is formed by electrodepositing metal onto a tapered mandrel, which prevents rust on the internal peripheral surface and eliminates the difficulty of post-processing.
4Object-affected harmful factors
If a thin needle is formed by conventional electroforming, then the needle can be manufactured, but pain is not sufficiently reduced due to external peripheral surface contact with pain spots
Solution Approach 1:
The needle is segmented into proximal and distal portions with different diameters. The distal portion has a smaller diameter that reduces contact with pain spots while maintaining sufficient structural integrity for puncture.
Solution Approach 2:
The needle exhibits local quality variations along its length, with the distal portion optimized for pain reduction through smaller diameter, and the proximal portion optimized for fluid flow through larger diameter.
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 needle design reduces pain by minimizing contact with pain spots and lowers flow resistance for medication injection, while being manufactured with high accuracy and at a lower cost due to the electroforming process and use of specific particles.
Implementation Method 1
a core material having a diameter corresponding to a passage of the needle is immersed in an electrolyte, an electroformed member is formed on an external peripheral surface of the core material
Implementation Method 2
a core material having a diameter corresponding to a passage of the needle is immersed in an electrolyte
Data Source
AI summary
A method for manufacturing a needle tapered along the longitudinal direction by electroforming comprises: a step of immersing a core material (122) having an outer peripheral surface that is tapered along the longitudinal direction in an electrolyte and forming a first electroformed body (126) on an outer peripheral surface (124) of the core material (122); a step of immersing the first electroformed body (126) in an electrolyte to which particles having a prescribed particle size are added and forming a second electroformed body (134) having multiple protrusions (30) on an outer peripheral surface (128) of the first electroformed body (126); a step of cutting the first electroformed body (126) and second electroformed body (134) into a prescribed length and forming a needle (10) having a sharp needle tip (16); and a step of pulling out the core material (122) from the cut first electroformed body (126).