The invention embodies a harvester (12) to convert energy from mechanical domain to electrical domain. The harvester comprises at least one inertial body (6), at least one beam (7, 9), a support (8) to said at least one beam (7, 9) and transducer means (10, 16), wherein said at least one beam (7, 9) configures the inertial body (6) into a pendulum structure being suspended from said support (8) so that the beam (7, 9) is allowed to bend according to the kinetic state changes of the inertial body (6), and is configured to interact with at least one transducer means (10) that is/are configured to produce change in the electrical state of said transducer means (10, 16) responsively to the kinetic state of the beam (7, 9). The invention also shows harvester module, matrix and a harvester system comprising at least one embodied harvester. The invention also shows a tire and a foot wear that comprises at least one harvester embodied.