Design and analysis of an untethered micro flapping robot which can glide on the water

Flapping-wing flying insects possess various advantages,such as high agility and efficiency.The design and manufacture of insect-scale flapping-wing micro aerial vehicle(FWMAV)have attracted increasing attention in recent decades.Due to the limitations of size and weight,the FWMAV with an onboard battery which can fully mimic insect flight has not been achieved.In this work,we design and fabricate a highly integrated flapping-wing microrobot named Robomoth.The Robomoth consists of a carbon chassis,customized power and control devices,and two piezoelectric ceramic actuators symmetrically distributed in the thorax and controlled individually.It weighs 2.487 g,spans 5.9 cm in length,possesses 9 cm of wingspan,and carries a 0.355 g rechargeable lithium battery.We demonstrate the mobility of the Robomoth through untethered gliding and making turns on the water surface.A simplified dynamic model of the flapping system is proposed to explain the relationship between the driving frequency and the flapping amplitude.The Robomoth is one new untethered bioinspired flapping-wing robot that can perform stable water surface motion,which holds potential applications such as search and rescue on the water.The robot can also provide insight for designing insect-scale flying vehicles.