Opportunity
The global drone market is rapidly expanding, with applications ranging from aerial photography and surveying to search and rescue operations. However, a significant limitation hinders broader and more advanced functionalities: payload constraints. Most consumer and enterprise drones carry limited onboard electronics beyond basic flight operations because adding more electronic components typically requires larger battery packs. This increase in payload leads to higher energy consumption, severely restricting flight duration and operational capabilities. Drones rely heavily on finite onboard power sources, primarily batteries, which curtails their ability to perform extended missions or support power-intensive sensors and communication systems. This dependency creates a critical need for alternative or supplemental power solutions that do not add substantial weight or compromise aerodynamics. Energy harvesting technologies present a promising avenue to address this challenge, enabling drones to become more autonomous and capable without sacrificing performance.
Technology
This patent introduces a hybrid unmanned aerial vehicle (UAV) integrated with a Drone Rotational Triboelectric Nanogenerator (DR-TENG) system. The innovation lies in directly capturing and recycling the kinetic energy from the drone's propeller rotations, which is otherwise wasted, and converting it into usable electrical energy. The system comprises multiple TENG units, each attached directly below a propeller on the drone's rotors. Each TENG unit features a co-planar arrangement with a rotor component and a stator component. The rotor component, attached to the spinning propeller, includes a dielectric triboelectric layer made of a material like fluorinated ethylene propylene (FEP) film. The stationary stator component includes a conductive layer, such as silver fabric tape. As the propeller rotates, the FEP film cyclically comes into near-contact with the conductive electrode. This interaction, based on the triboelectric effect and electrostatic induction, generates an alternating current (AC). The system is designed for minimal aerodynamic interference and lightweight integration. For a quadcopter, four TENG units are used, with units on propellers rotating in the same direction connected in series, and the two pairs with opposite rotations connected in parallel to maximize electrical output. The generated AC can be rectified to direct current (DC) to serve as a supplemental or alternative power source for onboard electronics or for storage in capacitors.
Advantages
- Provides a supplemental power source, reducing reliance on primary batteries and potentially extending flight time or enabling additional onboard electronics.
- Achieves a high surface power density of 3.4 W/m², making it efficient for its size.
- The system is lightweight (e.g., ~17.48g add-on) and designed to have negligible impact on the drone's battery consumption and flight performance.
- Features a simple design with a minimal number of components, facilitating ease of fabrication using cost-effective, widely available materials like 3D-printed substrates, FEP film, and silver conductive tape.
- Does not interfere with the aerodynamics of the drone during flight.
- Offers dual functionality: energy harvesting and self-powered sensing (e.g., RPM monitoring).
- The design is scalable; performance can be enhanced by increasing the number of TENG units.
Applications
- Powering onboard drone electronics such as sensors, cameras, GPS modules, and communication systems.
- Serving as a self-powered RPM sensor for real-time monitoring of propeller speed, enhancing flight control and safety.
- Charging capacitors to store harvested energy for later use by small electronic devices.
- Enabling extended environmental monitoring, surveillance, or mapping missions by supplementing power.
- Potential application in other rotating machinery (e.g., wind turbines, hybrid vehicles) for energy harvesting and speed monitoring.
