# A Robust Generator-Harvester for Independent Sensor Systems +
## 1 Introduction  
Between the years 2000 and 2020, the trends of energy saving, energy system independence, energy processing efficiency, and energy harvesting based on electromagnetic field principles [1] reached almost all industries. The field of energy harvesting, or the concept of energy transduction [2; 3; 4], does not cover the entire area of energy production and processing to convert diverse forms of energy into electricity; this domain includes only a limited part of the principles [5; 6; 7; 8] and corresponding device designs [9; 10; 11; 12] that allow exploiting unused types of energy for a given purpose [13; 14]. In power generation, specific energy conversion principles still remain to be included, such as the conversion of energy from flowing media (water, air) and the conversion of incident RF electromagnetic waves, namely, photovoltaic systems, into electricity [15; 16; 17]. Considering the scarcity of alternative energy sources, these may find application mainly in mobile or wireless devices [18; 19; 20], sensor-independent systems [3; 4], autonomoussensor instruments, and systems where a stable power supply is disadvantageous or impossible to secure [3; 4]. The requirement for the development and use of alternative energy source principles involves, among other factors, estimating the minimum operating time without a stable/permanent (non-mobile) distribution system. A narrower, more tightly defined segment of power harvesting and generation utilizes [PERSON]'s law of induction [1] in devices that employ vibration [3], rotational motion, and/or linear motion [2; 4; 5; 6]. These principles are further modified through various concepts of micro-, mini- [3], and large-sized generators [2]. In the last-named option, the power delivered is expected to be in the order of tens to thousands of watts, either discontinuously or in a continuous time. Such generators and design approaches must meet the desired lifetime requirements, and if they satisfy this prerequisite, they are referred to as robust. Designing conceptual solutions to enable a highly efficient conversion of motion into electrical energy is an interesting--and already partially solved--problem. The principle of converting motion energy into electricity is based on the understanding and consistent use of the possibilities of [PERSON]'s induction law [1], as presented in sources [3; 4] and [18; 19; 20] and as outlined hereabove. Researching and exploring suitable harvester concepts are steps that generally allow us to identify a highly efficient device to transform kinetic energy, potentially enabling the operator to power components such as sensors with permanently supplied electrical energy that may be of rare origin. In sensors and measuring systems, special transportation equipment, and cars, meaning items that feature a higher power consumption (P = 10-1000 W), the power supply of electricity from conventional sources such as batteries, internal combustion engines, and related sources is either disadvantageous in terms of the solution and cost or difficult to implement. For this reason, residual or alternative forms of energy are then widely sought for, including, but not limited to, the expansion of compressed air and various types of linear movement. The options of converting kinetic energy into electricity comprise, for example, the electromagnetic principle based on the full Faraday effect, the result being high conversion efficiency [1; 18; 19; 20]. The project presented herein expands on the concepts in paper [21], namely, efficient methods for generating and exploiting linear motion. In this article, however, the parameters of selected vibration harvesters are discussed and compared in greater detail, and, importantly, an estimation the expected characteristics inherent with the proposed implementation is outlined.