An experimental investigation on flapping wing flexibility for insect-inspired MAVs development

An experimental study on flapping wing flexibility in hovering flight has been conducted to investigate the wing flexibility for insect-inspired flapping Micro Aerial Vehicles (MAVs). Hawkmoth-like wing models, constructed from Plexiglas® (3 mm thick) and pristine Polycarbonate (PC) sheet (1, 0.5, and 0.2 mm thick) with a spanwise length of 200 mm and an aspect ratio of 6.18, were selected for preliminary experiment. The wing models were constrained to a simple harmonic flapping motion with sweeping and rotating amplitudes of 120° and 90° for hovering in water tank with size of 3.5 m×1.0 m×1.1 m. A six-axis force/torque sensor and a high speed camera with a Diode-Pumped Solid-State (DPSS) laser using Digital Particle Image Velocimetry (DPIV) were utilized to measure the aerodynamic forces and obtain flow visualization. Based on the experimental results, the aerodynamic forces diminish as the wing becomes flexible except for the wing with thickness of 1 mm. Consequently, this finding will instrumental in identifying the range of wing flexibilities that improve the aerodynamic efficiency for the development of insect-inspired flapping MAVs.