An insect-scale robot is capable of flying, swimming, impulsively taking off from the water surface, and landing.

We present a power and control autonomous, insect-scale legged robot the Harvard Ambulatory MicroRobot with RF communication (HAMR-F). At only 2.8 g and 4.5 cm in length, HAMR-F is capable of locomotion at speeds up to 17.2 cm/s (3.8 body lengths per second) with an onboard battery. Two microcontrollers and custom drive electronics independently control eight high-voltage piezoelectric actuators to enable gait flexibility and maneuverability across a range of stride frequencies. An onboard microelectromechanical systems (MEMS) inertial measurement unit provides feedback for controlled, straight-line running on this size- and weight-constrained mobile microrobot. The main contributions of this letter are: first, the design of lightweight power electronics for independently driving multiple high-voltage (200 V) piezoelectric actuators, second, a detailed characterization of HAMR-F's speed, maneuverability, and cost of transport, and finally, the integration of an onboard feedback controller for straight-line, high-speed running.

Flapping wings produce lift and thrust in bio-inspired aerial robots, leading to quiet, safe and efficient flight. However, to extend their application scope, these robots must perch and land, a feat widely demonstrated by birds. Despite recent progress, flapping-wing vehicles, or ornithopters, are to this day unable to stop their flight. In this paper, we present a process to autonomously land an ornithopter on a branch. This method describes the joint operation of a pitch-yaw-altitude flapping flight controller, an optical close-range correction system and a bistable claw appendage design that can grasp a branch within 25 milliseconds and re-open. We validate this method with a 700 g robot and demonstrate the first autonomous perching flight of a flapping-wing robot on a branch, a result replicated with a second robot. This work paves the way towards the application of flapping-wing robots for long-range missions, bird observation, manipulation, and outdoor flight.

Lightweight robots are capable of repeated aquatic jump-gliding through high-powered jet propulsion with water-reactive fuel.

Autonomous lightweight flapping-wing robots show potential to become a safe and affordable solution for rapidly deploying robots around humans and in complex environments. The absence of propellers makes such vehicles more resistant to physical contact, permitting flight in cluttered environments, and collaborating with humans. Importantly, the provision of thousands of species of birds that have already mastered the challenging task of flapping flight is a rich source of solutions. However, small wing flapping technology is still in its beginnings, with limited levels of autonomy and physical interaction capability with the environment. One significant limitation to this is the low payload available. Here we show the Eagle-inspired Flapping-wing robot E-Flap, a 510 g novel design capable of a 100% of payload, exceeding the requirement of the computing and sensing package needed to fly with a high degree of autonomy. The concept is extensively characterized, both in a tracked indoor space and in outdoor conditions. We demonstrate flight path angle of up to 50 $^\circ$ and velocities from as low as 2 m/s to over 6 m/s. Overall, the robotic platform has been proven to be reliable, having performed over 100 flights. Through mechanical and electronics advances, the E-Flap is a robust vehicle prototype and paves the way towards flapping-wing robots becoming a practical fully autonomous flying solution. Video attachment: https://youtu.be/GpAa176TMf0

Despite significant research progress on small-scale aerial-aquatic robots, most existing prototypes are still constrained by short operation times and limited performance in different fluids. The main challenge is to design a vehicle that satisfies the partially conflicting design requirements for aerial and aquatic operation. In this paper we present a new class of aerial-aquatic robot, the Sailing Micro Air Vehicle, ‘SailMAV’. Thanks to a three-part folding wing design, the SailMAV is capable of both flying and sailing. The robot design permits long and targeted missions at the water interface by leveraging the wind as movement vector. It simultaneously offers the flexibility of flight for rapidly reaching a designated area, overcoming obstacles and moving from one body of water to another, which can be very useful for water sampling in areas with many obstacles. With a total wingspan of 0.96 m, SailMAV employs the same wing and actuation surfaces for sailing as for flying. It is capable of water surface locomotion as well as take-off and flight at a cruising speed of 10.8 m/s. The main contributions of this paper are (i) new solutions to the challenges of combined aerial and aquatic locomotion, (ii) the design of a novel hybrid concept, (iii) the development of the control laws required, and (iv) the demonstration of the vehicle successfully sailing and taking off from water. The presented work can inform the design of hybrid vehicles that adapt their morphology to move effectively.