A review of Low-Power Energy Harvesting technologies in Industry 4.0

Nowadays, in the modern world, wireless electronic devices or those with wireless capabilities are significantly popular because there is no need for them to obtain any power connections to the main grid. As a result, batteries are now playing the main role in supplying power for electronic devices for household use or industrial use, making wire connection becomes the choice for battery charging purposes only. Battery manufacturing technology has made a huge step in improving battery life but still requires frequent maintenance which causes a big gap between battery life and the need of the users. Furthermore, recycling the depleted batteries after use is quite challenging despite many efforts being put into research for solutions to this matter. Even though some solutions were introduced as eco-friendly ones, their recycling problems are still in doubt, for example, recycling the PV panels or recycling the Lithium batteries from electric vehicles is still a headache for scientists. As it is now the trend of using "green electronics", it would be not a good approach to rely so much on the grid power supply. Energy has to be collected through the surrounding activities with the reduction of using Copper or wire in power transfer. There have been many scientific researchers who were interested in tackling this problem and they spent a lot of effort in researching energy harvesting technologies. As a result, different aspects of battery life and energy harvesting study have been taken into research, such as battery charging efficiency, energy collector efficiency, power converter efficiency, etc. For Industry 4.0, low-power energy harvesting is highly needed as the small sensors or small power modules will be leveraged by this kind of technology. This paper aims to examine the current state of knowledge on low-power energy harvesting technology, including its benefits, limitations, and future potential.