A security device watches over the secure functionality in a computer system. Adjacent to the image receiver is a breast support with a body and a plate. The posture angle calculation module calculates the current posture angles of the mobile carrier corresponding to different direction axes in a space according to signals input by one or multiple sensors. The resulting assembly is wound into a swirling shape in cross section about an axial core 7 to form an electrode group 5. Other embodiments may be described. The carbon fibers have average diameters less than about 300 nanometers.