Aerial-Aquatic Robots Capable of Crossing the Air-Water Boundary and Hitchhiking on Surfaces

ABSTRACT

Many real-world applications for robots—such as long-term aerial and underwater observation, cross-medium operations, and marine life surveys—require robots with the ability to move between the air-water boundary. Here, we describe an aerial-aquatic hitchhiking robot that is self-contained for flying, swimming, and attaching to surfaces in both air and water and that can seamlessly move between the two. We describe this robot’s redundant, hydrostatically enhanced hitchhiking device, inspired by the morphology of a remora (Echeneis naucrates) disc, which works in both air and water. As with the biological remora disc, this device has separate lamellar compartments for redundant sealing, which enables the robot to achieve adhesion and hitchhike with only partial disc attachment. The self-contained, rotor-based aerial-aquatic robot, which has passively morphing propellers that unfold in the air and fold underwater, can cross the air-water boundary in 0.35 seconds. The robot can perform rapid attachment and detachment on challenging surfaces both in air and under water, including curved, rough, incomplete, and biofouling surfaces, and achieve long-duration adhesion with minimal oscillation. We also show that the robot can attach to and hitchhike on moving surfaces. In field tests, we show that the robot can record video in both media and move objects across the air/water boundary in a mountain stream and the ocean. We envision that this study can pave the way for future robots with autonomous biological detection, monitoring, and tracking capabilities in a wide variety of aerial-aquatic environments.

Yiyuan Zhang is a PhD student advised by Prof. Cecilia Laschi at the Soft Robotics Lab at the National University of Singapore. He received his B.Sc degree with Beijing Outstanding Graduate Honors in Mechanical Engineering from Beihang University in 2022. He was the Research Assistant at the Biomechanics and Soft Robotics Lab at Beihang University under the supervision of Prof. Li Wen. Yiyuan's research topics include bio-inspired robotics/soft robotics design with embodied intelligence, especially octopus-inspired soft robot arm and remora-fish-inspired robots. His co-first authored Science Robotics paper has been featured by Science Magazine, NewScientist, China Daily, The New York Daily Paper, and other media presses.

Research in Acoustic Noise Reduction and Reconfiguration Antennas Inspired by Origami

ABSTRACT

Metasurfaces have developed rapidly in recent years, greatly improving the performance of acoustic materials based on metasurface design, and achieving functions that could not be achieved before. However, most of the hypersurfaces designed at present are designed for a single demand, and cannot achieve multi-function integration, while the reconfigurable hypersurface is a good solution to this problem. The existing reconfigurable metasurfaces have a simple structure and weak allosteric ability, which cannot meet the increasing needs of users. The rich geometry and motion characteristics of origami structure bring a new direction to the structural design of reconfigurable metasurface. Also, the reconfiguration antenna designed by origami can change their working frequencies and achieve the multiple functions.

Wang Yutao is a visiting PhD student in Department of Mechanical Engineering, NUS, under guidance of Prof. Khoo Boo Cheong and Prof. Lu Zhenbo. He comes from Southeast University in China. His research interests are about the design and application of origami. He majors in acoustic noise reduction and reconfiguration antennas inspired by origami. Wang Yutao has published three journal papers and four conference papers till now.