Direct Writing Conformal Magnets for Position Sensing
Solution Overview
Problem
Existing magnet technologies used in position sensing systems on rotating components, such as shafts and rotors, face challenges in minimizing size and mass while maintaining high magnetic flux density, which is essential for efficient performance and control systems.
Innovation Solution
A method for direct writing of conformal and free-form magnets using a magnetic ink compound composed of a photopolymer resin base and magnetic material powder, where the ink is extruded, soft-cured, and post-cured to achieve structural strength and optimal magnetic properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If magnets are made smaller to fit within tight air gaps and minimize added volume and mass, then the magnetic flux density must be increased sufficiently to maintain desired response from magnetic detectors
Solution Approach 1:
The patent uses a composite material consisting of magnetic powder particles suspended in a curable resin matrix. This composite structure allows the magnet to achieve high magnetic flux density through the concentrated magnetic powder while maintaining small volume through the low-viscosity resin that can be precisely deposited in minimal quantities. The composite nature enables independent optimization of magnetic properties and structural form.
Solution Approach 2:
The patent employs parameter changes by controlling the viscosity of the magnetic ink through resin selection and by precisely controlling the deposition thickness and curing parameters. The magnetic properties are optimized by adjusting the magnetic powder concentration, particle size distribution, and magnetic field application during curing, allowing high flux density in compact dimensions.
2Manufacturing precision
If traditional magnet manufacturing methods are used, then magnets can be produced with sufficient magnetic properties, but material waste is significant and intricate patterns are difficult to achieve
Solution Approach 1:
The patent applies local quality by using direct write deposition to place magnetic ink only where magnets are needed, with precise control over the spatial distribution, thickness, and shape of each magnet. This localized deposition eliminates material waste in non-magnet areas and enables intricate patterns that would be impossible with conventional molding or machining methods.
Solution Approach 2:
The patent replaces traditional mechanical magnet manufacturing processes (molding, machining, assembly) with a direct write deposition and curing process. This substitution eliminates the need for physical tooling, reduces material waste through precise digital control of deposition, and enables complex three-dimensional patterns that cannot be achieved with mechanical methods.
3Volume of moving object
If magnets are made as small as possible, then they fit within tight air gaps, but the structural strength and handling properties become compromised
Solution Approach 1:
The patent uses phase transition of the resin from liquid to solid through UV or thermal curing. The magnetic ink is applied in a low-viscosity liquid state that allows precise deposition of small magnet volumes, then cured to transform into a solid structure with adequate mechanical strength for handling and installation. This phase transition enables small size while maintaining structural integrity.
Solution Approach 2:
The resin matrix acts as an intermediary between the magnetic powder particles and the external environment. It binds the magnetic particles together to form a structurally sound unit while allowing the magnet to be deposited in small volumes. The cured resin provides the mechanical strength needed for handling small magnets, while the magnetic powder provides the magnetic flux density.
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 allows for the creation of small, lightweight magnets with high magnetic flux density, reducing material waste and enabling intricate patterns, thus enhancing the performance and miniaturization of position sensing systems and control systems.
Implementation Method 1
a magnetic ink compound comprised of a photopolymer resin base and a magnetic material powder
Data Source
AI summary
A system for direct writing a conformal or free-form magnet includes producing a magnetic ink compound by mixing an photopolymer base and a magnetic material powder, extruding a layer of the magnetic ink compound through a nozzle on to a target substrate to form a layer, soft-curing the layer by exposing the layer to a first light, repeatedly extruding a layer and soft-curing the layer, then post-curing the magnet by exposing the magnet to a second light and an elevated temperature.