NOVELTY - The absorber has a rotational motor and a central shaft inserted through a central opening of an annular axial magnet. The shaft is combined with a set of magnet units forming a magnet assembly (110) slidably inserted into a central cavity of a hollow tube (122). A cylindrical shell comprises an end attached to a terminal end of the magnet assembly, where the shell is extended along the length of the magnet assembly. Inner diameter of the shell slidably accommodates the outside diameter of a coil assembly (120).    USE - Electricity generating shock absorber e.g. linear electromagnetic shock absorber, single layer electricity generating shock absorber, double layer electricity generating shock absorber and gear-based electricity generating shock absorber, for generating electricity from mechanical vibrations i.e. suspension vibrations, between a wheel i.e. automobile wheel, and a sprung mass, in a suspension system of a motor vehicle or land-based vehicle e.g. car. Can also be used for charging a battery, powering an electrical accessory e.g. light or radio, and driving wheels of a hybrid vehicle, and for bus, lorry, train, marine-based vehicle e.g. ship and boat, and aeronautical vehicle e.g. airplane, helicopter and spacecraft.    ADVANTAGE - The absorber maintains or enhances required suspension damping performance and effectively adjusts a suspension damping according to driver need or road conditions. The absorber maintains or enhances vibration mitigation performance, so that the absorber can provide back electromagnetic force acting as damping or control force. The absorber performs energy harvesting operations under a set of normal driving conditions in an efficient manner. The absorber is properly sized to accommodate multiple loads and forces experienced by the absorber. The absorber is capable of achieving high energy density, reduced weight and compactness in an efficient manner. The absorber easily implements a regenerative active suspension and a combination of energy harvesting and active suspension control. The absorber can be retrofitted to the existing car.    DETAILED DESCRIPTION - The magnet unit includes an annular radial magnet and an annular axial magnet. The coil assembly is made of electrically conducting material. The absorber has a concentric outer cylinder made of magnetically-permeable material. INDEPENDENT CLAIMS are also included for the following:    (1) a method for manufacturing an electricity generating shock absorber    (2) a method for generating electricity from mechanical vibrations.    DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a linear electromagnetic shock absorber.    Magnet assembly (110)    Coil assembly (120)    Coils (121)    Hollow tube (122)