There are a few ways to do this, but the Halbach array, as [wannabemadsci] explains, allows you to make an array of magnets where one side is very strong, and the other side is very weak.

This paper presents a new design of Magnetic-Geared Permanent Magnet (PM) machine based on Halbach array magnetic arrangement. By creating stronger and more effective coupling between generated ...

This paper presents the magnetic field analysis for the double layer Halbach array voice coil actuator (VCA). This VCA is composed of a stator and a mover supported by the flexure-based bearings. The ...

German physicists have overcome a long-standing limitation of magnetic field design by outperforming the famed Halbach array with a compact setup that delivers cheaper, stronger, and more uniform ...