The invention relates to a method for forming a body comprising a particle structure fixated in a matrix material, comprising: Providing an amount of particles, Providing a viscous matrix material to include said particles, Forming a particle structure of at least a portion of said amount of particles, Fixating said viscous matrix so as to fixate said particle structure in the matrix material; characterized by at least a portion of said amount of particles being paramagnetic or ferromagnetic and the formation of the particle structure includes the steps of: First, the particles are provided in a mixture with the viscous matrix material, Second, the viscous mixture is subject to the magnetic field created by a Halbach array so as to form the particle assemblies, Third, the viscous mixture with the particle assemblies is subject to electric field so as to move and/or rotate the particle assemblies in the viscous matrix material. The invention also relates to a body obtained by said method, and to the use of said method in various applications.