An energy absorbing device for a collapsible steering column of a vehicle includes an M-shaped plastically deformable strap for imposing a resistance to collapse of the steering column when the steering column collapses in a vehicle collision. The detector material includes a substantially regular array of nano-particles embedded in a matrix material. This provides an increased pull-out strength of the suture and resistance to shear stresses, improving the quality of the repair. The opening space formed between the ferromagnetic material plates also facilitates maintenance of the cryocooler and the motor. The mask and sidewall layer are removed.