The process of powering devices by utilizing smaller volumes of energy from one or more ambient energy sources is called Energy Harvesting (EH). Energy harvested from the ambient sources can also be stored in a battery for future usage. The future of new energy harvesting technologies is promising and they have begun to gain market share. The technologies will power machines and equipment in areas that were inaccessible before.
Different types of ambient energy sources include mechanical, thermal, light, electromagnetic, radio frequency (RF) waves and natural. The most promising technologies for lower power applications are solar, thermal, and mechanical energy sources.
Organizations are coming forward with novel solutions to increase power density and conversion efficiency. North America is an important market for EH and is among the leading regions in research and development for EH technologies. Europe is expected to accelerate adoption in the coming years, with a current focus on research on the benefits of energy harvesting for well-being and health. Nano-scale manipulation of devices and nano-materials are key emerging focus areas in EH research.
Energy harvesting technology is considered ‘smart’ as it leverages natural sources to power various electronic devices. It also eliminates the disposal issues related to the batteries. Self-powered ubiquitous sensor networks are greatly enabled by EH technology. The technology is gaining momentum in multiple industries with expanding capabilities. The applications enabled by energy harvesting technologies for unmanned aerial vehicle are as follows:
Waste heat Generator: Thermoelectric energy harvesting is being adopted to generate power from waste heat. When drones are exposed to extreme temperatures, it can be utilized to power various electronic components.
Wireless Sensor Network: Vibrations are present in all aircrafts to a varying degrees and at various frequencies. In fixed wing drones there has been an interest in harvesting vibrations from large structures such as the composite wings and in engine casings. These vibrations can be used to power wireless sensors.
Monitoring Landing Gear Subsystem: A lot of heat is generated in drone wheels and brakes during landing. This heat can be harvested with the help of thermoelectric components and in addition, the waste heat can be harvestedfrom the wheels’ and brakes’ pressure.
Structural Health Monitoring: The structural health monitoring is conducted on the ground and in the air. Thousands of sensors are deployed to carry out structural health monitoring operations; these sensors are powered with the help of wires and batteries. These power sources increase the weight of the drone. The waste heat and vibrations from the different parts of the drone can be useful to power the sensors employed for structural health monitoring.
Seat Status Monitoring: Vibration is present in the aircraft at varying degrees and at various frequencies. In fixed wing drones there has been interest in harvesting vibrations from large structures such as the composite wings and engine casing. These vibrations can be used to power wireless sensors.
Battery Thermal Management: Battery cells are enabling drones; temperature is one of the most important factors for battery cell operational condition. Thus, thermal management policies are very useful to prevent battery damage from very low and very high temperatures.
Large companies should enter the drones market by understanding the potential of small technology developers and enter into alliances and partnerships with them. Such partnerships and collaborations would bring innovative technologies into the market at a faster pace. Regulators, OEMs, system integrators, research organizations, and operators should work together to develop standards for structural health monitoring technologies. Certification agencies should be established to identify technology gaps before taking the technology to field applications. To integrate the energy harvesting technology in these devices, manufacturers need to work in collaborations. The energy harvesting technology is considered smart because it saves natural resources and provides unique methods of powering low-power devices.