Inert Sampling Needle With PEEK Sheath for Septum Piercing
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Solution Overview
Problem
Inert sampling needles that can withstand repeated use and provide sufficient strength to pierce septa and seal to injection ports without exposing samples to reactive materials are lacking in existing technologies, as metal needles corrode or interact with samples, and coatings degrade over time.
Innovation Solution
A sampling needle with a hollow rigid support member covered by a sheath member formed from inert materials like polyetheretherketone, which isolates the support member from the sample environment, providing structural integrity and preventing sample exposure to metal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a metal needle is used to pierce septa and deliver samples, then sufficient strength and fatigue resistance are achieved, but the metal needle corrodes or interacts with samples causing reactive interference
Solution Approach 1:
The needle is divided into two distinct components: a metal support member that provides structural strength and an inert sheath member that contacts the sample. This segmentation allows each component to perform its specialized function without compromise.
Solution Approach 2:
The inert sheath member acts as an intermediary between the metal support member and the sample. It transfers the mechanical function of sample delivery while blocking direct contact between the reactive metal and the sample, eliminating reactive interference.
2Object-generated harmful factors
If an inert material like PEEK is used to aspirate sample, then reactive interference is eliminated, but the material is too soft to pierce septum and seal to injection port
Solution Approach 1:
The needle is divided into two distinct components: a metal support member that provides structural strength and an inert sheath member that contacts the sample. This segmentation allows each component to perform its specialized function without compromise.
Solution Approach 2:
The needle combines two different materials with complementary properties: metal for strength and inert material for chemical compatibility. This composite structure achieves both mechanical performance and chemical inertness simultaneously.
3Object-generated harmful factors
If a Teflon coating is applied to stainless steel needle, then reactive interference is reduced, but the coating degrades and wears off with time
Solution Approach 1:
The needle is divided into two distinct components: a metal support member that provides structural strength and an inert sheath member that contacts the sample. This segmentation allows each component to perform its specialized function without compromise.
Solution Approach 2:
Rather than relying on degradable coatings, the invention uses a complete inert sheath member that can be replaced as a unit when worn, ensuring consistent performance throughout the needle's service life.
4Object-generated harmful factors
If a PEEK inner tube is used in the needle, then sample interaction is prevented, but the tube lacks strength to seal to injection port and requires additional interface members
Solution Approach 1:
The metal support member and inert sheath member are merged into a single integrated needle assembly where the sheath is affixed to the support member. This combination eliminates the need for separate interface members while maintaining both strength and inertness.
Solution Approach 2:
The needle combines two different materials with complementary properties: metal for strength and inert material for chemical compatibility. This composite structure achieves both mechanical performance and chemical inertness simultaneously.
Data Source
AI summary
A inert sampling needle is provided for piercing a septum of a vial containing a sample. The sampling needle includes a hollow rigid support member having an inner wall, an outer wall, and a septum-piercing end. The sampling needle also includes a sheath member affixed to the rigid support member. The sheath member covers the septum-piercing end of the support member, the inner wall, and at least a portion of the outer wall adjacent the septum-piercing end to isolate the support member from the sample. Preferably, the sheath member is formed of polyetheretherketone and is affixed to the rigid support member by heat fusing. A method of forming, and a method of using the inert sampling needle is also disclosed.