Introduction -- Energy harvesting techniques and trends in applications -- Material and components selection for efficient energy harvesting -- RF and millimeter wave energy harvesting techniques and applications -- Energy harvesting systems for agriculture needs -- Acoustic signal energy harvesting techniques and relevant systems -- Bio-medical devices adopting energy harvesting schemes -- Wireless sensor networks, smart electronic gadget energy needs and energy harvesting systems -- Piezo energy harvesting and application prospects -- Energy harvesting systems for military, space and defence applications -- Mechanical energy harvesting scheme and implementation aspects, applications -- Fluid based energy harvesting systems for electronic appliances -- Energy harvesting schemes for home appliances, vehicles, chargers -- Light energy harvesting systems and applications -- Thermal energy harvesting prospects, systems and applications -- Conclusion.