Magnetising Portion With Non-Magnetic Spacers
Solution Overview
Problem
Current magnetic separation devices face limitations in generating a high-gradient magnetic field, particularly for isolating nanometre-sized particles, due to the compromise in magnetic field strength and gradient caused by magnets being in contact with each other, leading to inefficient and inaccurate separation processes.
Innovation Solution
A magnetising portion comprising a plurality of magnets arranged alternately with non-magnetic spacing means between them, creating a high-gradient magnetic field by directing magnetic flux outwardly, rather than through adjacent magnets, ensuring consistent performance across the field.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If magnets are arranged in contact with each other in alternating polarity, then the magnetic assembly structure is compact and easy to manufacture, but the fringe magnetic field strength and gradient are compromised
Solution Approach 1:
A non-magnetic spacer is introduced as an intermediary element between adjacent magnets with alternating polarity. This spacer prevents direct magnetic coupling between the magnets, forcing the magnetic flux to travel outwardly around the periphery rather than directly through the contacting magnets. This maintains the compact alternating polarity structure while restoring the fringe magnetic field strength and gradient necessary for effective particle separation.
2Device complexity
If magnets are placed in contact to create compact assembly, then device complexity is reduced, but the gradient of the fringe magnetic field is minimised
Solution Approach 1:
The non-magnetic spacer acts as a mediator that preserves the high magnetic field gradient by preventing flux short-circuiting between adjacent magnets. While adding a simple component, it maintains the precision of the magnetic field gradient without requiring complex magnet arrangements or precise positioning mechanisms.
3Productivity
If magnetic flux travels directly through contacting magnets, then the magnetic assembly is efficient, but the fringe field strength is limited
Solution Approach 1:
The non-magnetic spacer redirects the magnetic flux path to travel outwardly through the fringe field region rather than directly through the magnets. This intermediary element sacrifices some internal flux efficiency to generate a stronger external fringe magnetic field, enabling effective attraction and separation of magnetically labelled particles.
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 solution enables the effective isolation of nanometre-sized particles with improved efficiency and accuracy, providing a consistent high-gradient magnetic field that attracts and separates magnetically labelled particles rapidly and uniformly.
Implementation Method 1
A high-gradient magnetic field is conventionally created by configuring magnets to provide a magnetic field with regions of high magnetic field density and regions of low magnetic field density. The gradient of the magnetic field is the variation in field strength between the high density regions and low density regions.
Implementation Method 2
The strength of the fringe magnetic field is limited because the return flux travels directly through the contacting adjacent magnets to the opposite poles rather than travelling outwardly around the periphery of the magnets towards the opposite poles of adjacent magnets.
Implementation Method 3
The use of a high-gradient magnetic field to attract and separate magnetically labelled particles from a fluid in which they are suspended is well known.
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 2c
AI summary
The present disclosure relates to a magnetising portion for providing a high-gradient magnetic field in a magnetic separation device. The magnetising portion comprises at least one magnetic assembly. The at least one magnetic assembly comprises: a plurality of magnets whereby each magnet has a north pole, south pole and a magnet axis extending between the north and south poles, and the plurality of magnets are arranged one above the other in a direction at least substantially perpendicular to the axis of each magnet in such a manner that the north and south poles of adjacent magnets are arranged alternately and a space is provide between adjacent magnets; and at least one non-magnetic spacing means arranged in the space between adjacent magnets. The present disclosure also relates to magnetic separation devices comprising at least one of the said magnetising portions and to a method of isolating magnetically labelled particles using the magnetic separation devices.