Measuring differential pressures with multiple MEMS sensors during takeoffof an insect-like ornithopter

In this study, the differential pressure distribution on the wing surface of an insect-like ornithopter was measured directly. Three microelectromechanical system (MEMS) differential pressure sensors were attached to a wing surface in the spanwise direction. The wing length, flapping frequency, and total weight of the ornithopter were 110 mm, 15 Hz, and 7.1 g, respectively. The attachment points corresponded to 25%, 50% and 75% of the wing length and 20% of the length of the wing chord. The ornithopter took offin anterosuperior mode without yawing or rolling. At takeoff, the flapping motion of the wing induced a periodic differential pressure between the upstroke and downstroke. The average values of the maximum differential pressures were 23.5 ± 3.5 Pa, 45.2 ± 3.4 Pa, and 96.7 ± 10.0 Pa at the wing root (WR), wing center (WC), and wing tip (WT), respectively. The maximum differential pressures shifted from the WT to WR in the spanwise direction. These results reflected the aerodynamic forces acting on the insect-like ornithopter during takeoff.