TY - JOUR
T1 - Simple and Fast Locomotion of Vibrating Asymmetric Soft Robots
AU - Sabbadini, Alberico
AU - Atalla, Mostafa A.
AU - Wiertlewski, Michaël
PY - 2023
Y1 - 2023
N2 - To be fully integrated into the activities of our daily lives, robots need to be capable of traversing unstructured environments and interacting safely with their surroundings. Soft robots are perfect candidates since they can adapt to their surroundings through passive material compliance, rather than relying on complex control. However, the same compliance hinders the generation of propelling forces, and current approaches face a trade-off between traveling speed, action range, and control complexity. We overcome this trade-off by developing a locomotion mechanism based on the synergistic interaction between symmetric vibrations, elasticity, and asymmetric morphology. We then realize a rapid soft locomotor using inexpensive off-the-shelf components and requiring only elementary actuation and control. A single robotic unit can travel at speeds up to 100 mm/s when tethered and 35 mm/s when untethered. We derive a model that predicts the speed of the robot as a function of several design parameters and physical properties, highlighting the role of geometric asymmetries in the resulting anisotropic motion. Moreover, these elementary units can be added together to create more complex behaviors. By adding 2 units in parallel, the assembly can locomote and be steered following nonholonomic constraints. Our approach opens the door to a new class of low-cost soft robots that can travel fast and far with elementary fabrication and control, and which can be combined to achieve complex functions without compromising their essential simplicity.
AB - To be fully integrated into the activities of our daily lives, robots need to be capable of traversing unstructured environments and interacting safely with their surroundings. Soft robots are perfect candidates since they can adapt to their surroundings through passive material compliance, rather than relying on complex control. However, the same compliance hinders the generation of propelling forces, and current approaches face a trade-off between traveling speed, action range, and control complexity. We overcome this trade-off by developing a locomotion mechanism based on the synergistic interaction between symmetric vibrations, elasticity, and asymmetric morphology. We then realize a rapid soft locomotor using inexpensive off-the-shelf components and requiring only elementary actuation and control. A single robotic unit can travel at speeds up to 100 mm/s when tethered and 35 mm/s when untethered. We derive a model that predicts the speed of the robot as a function of several design parameters and physical properties, highlighting the role of geometric asymmetries in the resulting anisotropic motion. Moreover, these elementary units can be added together to create more complex behaviors. By adding 2 units in parallel, the assembly can locomote and be steered following nonholonomic constraints. Our approach opens the door to a new class of low-cost soft robots that can travel fast and far with elementary fabrication and control, and which can be combined to achieve complex functions without compromising their essential simplicity.
KW - fast locomotion
KW - frictional anisotropy
KW - soft robotic locomotion
KW - untethered
KW - vibration
UR - http://www.scopus.com/inward/record.url?scp=85166533582&partnerID=8YFLogxK
U2 - 10.1089/soro.2022.0209
DO - 10.1089/soro.2022.0209
M3 - Article
AN - SCOPUS:85166533582
SN - 2169-5172
VL - 10
SP - 1199
EP - 1208
JO - Soft Robotics
JF - Soft Robotics
IS - 6
ER -