IoT ecosystem confides a spectrum of layers when it comes to heterogeneous smart devices ranging from mini to jumbo including self powered, battery powered, main connected etc consuming variable amount of energy. Amongst these the devices operating upon battery or the ones which are battery operated are fortunate enough to exploit energy harvesting options. Further, it becomes quite important that these energy harvesting techniques must be supporting crucial aspects in the IoT environment as those of mobility, longer life time, sustainability to hold ecological balance, low cost for enhancing popularity and environment friendly. In the similar context, recently some popular energy harvesting techniques have been designed inculcating Radio Frequency Energy Harvesting utilizing magnetic inductive coupling effect for energy generation supporting wireless networks, WiFi, 4G technologies,   Thermal energy Generators generating electrical energy utilizing temperature differences, Photovoltaic and Solar energy generating DC power while making use of sunlight focussed on semiconductor materials, Piezoelectric, electrostatic, electromagnetic energy generators using stress-strain, pressure and vibrations while rotating a magnet around a coil. All these mechanisms and trends are amalgamated for powering up various IoT devices. Energy harvesting from human body is also being considered in a lot of wearable devices now a days. Amongst all these techniques Piezoelectric energy harvesting design considerations are quite in trend in the present times for optimizing the performance and leveraging good energy efficiency. Lots of IoT applications are making use of many of these energy harvesting techniques either individually or in hybrid modes. For example, smart factories, smart environmental monitoring, smart healthcare, smart agriculture, smart infrastructure to name a few. From an economic perspective, smart factories including Industry 4.0 and Wireless Sensor Networks are witnessing exponential growth in the green energy harvesting domain due to benefits like high efficiency, power output and reliability. To conclude, in the IoT ecosystem, due to the soaking of transmission of power into a wide range of wireless technologies, these green energy harvesting mechanisms have a long vital journey of key role to play to increase IoT device lifetime offering sustainable way to power up the batteries.

Dr. Chetna Dabas