In earlier studies, the optimal wing kinematics that gives the best aerodynamic performance was determined with a robotic flapper. The geometry and physical properties of wings are also critical for designing and fabricating Flapping Wing Micro Air Vehicles (FWMAVs). In this paper, the effects of wing aspect ratio and flexibility on aerodynamic performance are experimentally investigated to determine the optimal aspect ratio for Micro Air Vehicles (MAVs) wings at Reynolds number around 18,000. The comparison between the aerodynamic performance of rigid wings and flexible wings are also made whose veins are fabricated out of different materials.

Design of a flapping mechanism for flapping wing micro air vehicles (FWMAV) is presented based on a mathematical model of insect thorax. This model also includes an aerodynamic model of flapping wings. Using experiments on dynamically scaled wings and numerical optimization, the mechanism is tuned for peak aerodynamic performance. The thorax model is used to understand the mechanics of the biological flapping mechanism and reveals the significance of rotational stiffness and inertia distribution in flapping wings. Experiments conducted on the actual thorax based mechanism validate theoretical findings and also show significant lift generation capability.

In this paper, we investigate design and performance of a flapping mechanism which generates flapping motion through resonant excitation similar to flight apparatus of insects. The desired flapping motion is based on optimum aerodynamic efficiency. The mechanism is driven by a conventional motor and gearbox. The rotary motion is converted into oscillatory excitation through a four-bar linkage. This study explores the optimal design parameters of this mechanism for peak performance.

In this paper, we investigate designs of flapping mechanisms that allow high amplitude and high frequency of flapping. The mechanism utilizes springs and passive flapping, a concept motivated from the study of wing motion of insects and hummingbirds. The mechanisms simulate transverse bending effect of insect wings to achieve high flapping amplitudes. Different configurations of flapping mechanism are studied using dynamic simulations and quasi-steady aerodynamics. Apart from high amplitude, the results show that higher lift can be generated using these designs

In this paper, the energetics of a flapping wing micro air vehicle is analyzed with the objective of design of flapping wing air vehicles. The salient features of this study are: (i) design of an energy storage mechanism in the air vehicle similar to an insect thorax which stores part of the kinetic energy of the wing as elastic potential energy in the thorax during a flapping cycle; (ii) inclusion of simplified aerodynamic wing models and inertia of the mechanism using rigid body modeling techniques; (iii) optimization of parameters of the energy storage mechanism using the dynamic models so that energy input from the external actuators during a flapping cycle is minimized. A series of engineering prototypes based on these studies have been fabricated which justify the use of these mathematical techniques.