Compliant Multifunctional Wing Structures for Flapping Wing MAVs

Abstract

The flight time of miniature air vehicles (MAVs) is limited by the need for a portable, light weight power source. The development of multifunctional, power generating wings has the capability of extending flight time without compromising overall flight performance. This paper seeks to investigate the feasibility of integrating flexible solar cells onto the flapping wings of a MAV to create “compliant multifunctional wing structures”. Data is collected for bird-inspired miniature air vehicle wings designed with carbon fiber spars, and for comparable wings designed with a monolithic compliant component. Both of the designs are tested with wing bodies composed of plain Mylar foil with flexible, lightweight solar cells integrated onto them. The test setup is designed to simulate MAV operation under zero forward velocity. A motor that controls the wing flapping scheme is fixed to a rigid test stand. A 6 degree of freedom (DOF) load cell is used to measure aerodynamic lift as a function of time for a synchronized flapping scheme during wind tunnel testing. A second experiment is conducted to verify the functionality of solar cells as a regenerative energy source in real flight. A single compliant wing and a single regular wing are consecutively fixed to the test setup used in the first experiment, and the test is conducted under direct sunlight. The voltage generated by the solar cells is collected as a function of time, while the wing is flapping. The lift data is used to estimate flight characteristics, while the voltage data is used to estimate the viability of energy harvesting.