Polymagnets® contain many smaller magnetic elements that can produce superior attachment forces, safer magnets, precision alignment, shear and torque stiffness, and complex, multi-level/multi-force functions never before achieved with traditional bulk magnets.
Polymagnet technology enables unprecedented control over magnet interaction by applying the principles of signal processing theory and correlation methods to a pattern of magnetic elements on the magnet surface. Each Polymagnet comprises a number of pixel-like elements called maxels. The arrangement or pattern of these maxels creates a unique magnetic circuit that defines the function of the Polymagnet device and its interaction with other magnets and ferrous metals.
The basic principle behind the interaction of Polymagnets is correlation, in which magnetic fields add to or subtract from the aggregate forces depending on the orientation of the maxels. Patterns can vary according to the number, location, size, shape and amplitude of the maxels that constitute the Polymagnet. If you consider other variable parameters such as material grade & chemistry, surface geometry, and even dipole orientation, the possible combinations reach toward infinity.
The correlated magnetics approach enables programming of the magnet forces, tailored to meet your specific application requirements. Polymagnets can be programmed to have unique identities, to exhibit multiple forces simultaneously, and to provide significant improvements in magnet performance over conventional magnets. Among the many advantages of Polymagnets are…
Stronger forces
CMR’s MaxField® technology produces significantly stronger coupling forces than conventional, commercially available magnets. By concentrating magnetic flux at the surface of the magnet, more magnetic force is created between another MaxField magnet or a ferrous metal surface. A MaxField magnet can be tuned to thickness of metal so that strong coupling forces can be achieved with any metal thickness, including very thin metal down to thousandths of an inch.
Shown below are the attract force profiles of a pair of MaxField magnets versus a pair of conventionally magnetized magnets. For this particular configuration, the MaxField peak attach force is more than 250lbs compared to approximately 40lbs for the conventional pair.
Safer magnets
By tuning the reach of the magnetic field, CMR’s Polymagnet® technology reduces stray magnetic fields that can accidentally attract nearby metal or other magnets. Concentrating the available magnetic flux into a prescribed near-surface region means that even large high-energy magnets can be configured to achieve incredible attach force while reducing the risk of unintended attraction and acceleration of metal objects or other magnets. This field control and containment can even protect volatile magnetic storage devices from damaging stray fields.
Shown below are the attract force profiles of a pair of MaxField magnets versus a conventionally magnetized pair that deliver equivalent maximum attach strength. The conventionally magnetized pair are very dangerous due to the long reach of the magnetic field. The MaxField flux density is near zero at less than a quarter of an inch separation.
Precision alignment
Polymagnet® technology provides powerful new magnetic tools to enable precision-tailored alignment functionality. By varying the number of magnetic elements, materials, and maxel pattern, designers can engineer Polymagnet alignment to very tight tolerance. Auto-alignment means the positioning can be “assisted” by the magnetic field to achieve repeatable, precision positioning from a coarsely aligned mechanical or manual placement. Polymagnet alignment devices can be programmed to attach at one position only, or at multiple positions, at prescribed rotation angles, lateral translation, or other spatial arrangement.
Shear stiffness
Magnetic shear forces are traditionally weak relative to the attract and repel forces developed normal to a magnet surface. This is true for both magnet-to-metal and magnet-to-magnet applications. Polymagnets® can be designed to significantly increase the shear forces in both cases by improving the magnetic shear densities between magnets and improving the attach force between a magnet and a metal target surface. This Polymagnet advantage is even more pronounced as the magnet and/or metal surface thickness decreases. Better magnetic attach performance with less material, lower weight, smaller volume, and reduced costs.
Torque transfer
Magnetic gears and couplings offer decided advantages over mechanical couplings because they eliminate wear and suppress vibration, which means that they also eliminate various costs associated with cooling, lubrication and maintenance. However, magnetic couplings using conventional magnets are limited in attainable torque density and the systems tend to be large, heavy, and expensive. Polymagnet® technology provides superior torque density, and can be tuned for specific applications by varying the spatial frequency (transition from north polarity to south polarity) of the maxel regions.
Multi-level magnetic systems
Polymagnet® technology confers to the magnet designer precise control over magnetic fields in terms of reach, flux density, and three-dimensional shape of the field. In addition, the polarity mix for a given pattern can produce local attract or repel forces. These fields and forces can be combined to produce magnets that attract at a distance and repel in close proximity. Conversely, a multi-level design approach can produce a Polymagnet system where the components repel each other at a distance and attract each other in close proximity. The resulting behavior becomes a useful design functionality for attachment devices, motion actuators, and much more. Shown at below are separate attract and repel force profiles that, when added together, produce a composite force profile that delivers a “contactless attachment” functionality.
Complex magnetic fields
The CMR MagPrinter® can create complex, multipole magnetic systems from ordinary magnetizable materials such as rare-earth magnets, ceramics (ferrites), and flexibles. Pixel-like magnetic elements (maxels) can be aggregated to form very intricate magnetic fields, much like picture elements can render content rich images. The MagPrinter can produce a wide variety of maxel sizes and shapes, enabling a nearly limitless set of unique magnetic field designs imprinted into permanent magnet materials. Security devices, Maxel Imaging, and anti-counterfeiting applications can employ CMR technology to push the state of the art using magnetic fields created reliably by the CMR MagPrinter.
