Different sources of energy harvesting: A survey

21st Century has seen a paradigm shift in use of technology and the thoughts of using the natural sources for energy has led to thinking of using the energy wasted around us, in technical term, we can say harvesting of the energy. The paper aims at covering various techniques used in harvesting energy with focus on cantilever based energy harvesting. Interestingly the vibrations can be captured and converted into electricity. Up until now researchers have been able to produce upto 66 μ-w electricity using cantilevers with different materials in fans and bridges. Sources for energy harvesting and techniques have been covered in the paper.