A grasshopper-inspired glider: a study of gliding efficiency and wing morphology

Recent advances in imaging, manufacturing and microelectronics have made insect-scale robotics a reality. Many flying insect-scale robots rely on continuous wing flapping for locomotion. However, the energetic cost of flapping is prohibitive and usually results in most of these robots being tethered to off-board power and electronics. In this article, we present an insect-scale glider. The glider is inspired by grasshoppers, an order of insects that have been observed to glide intermittently between bursts of flapping flight, presumably to reduce their energy consumption. We characterized the hindwing morphology of collected grasshoppers. We also present preliminary wind tunnel experiments of hindwing models based on the morphology characterization, and free-flight testing results of the grasshopper-inspired glider. Results show that the glider has a lift-to-drag ratio of 2.9, producing a glide ratio better than projectile motion. However, this lift-to-drag ratio is less than those measured from actual grasshoppers during gliding. Future studies will focus on including more grasshopper wing design features associated with aerodynamic improvements, such as wing corrugations.