Multigait soft robot

Abstract

This manuscript describes a unique class of locomotive robot: A soft robot, composed exclusively of soft materials (elastomeric polymers), which is inspired by animals (e.g., squid, starfish, worms) that do not have hard internal skeletons. Soft lithography was used to fabricate a pneumatically actuated robot capable of sophisticated locomotion (e.g., fluid movement of limbs and multiple gaits). This robot is quadrupedal; it uses no sensors, only five actuators, and a simple pneumatic valving system that operates at low pressures (<10 psi). A combination of crawling and undulation gaits allowed this robot to navigate a difficult obstacle. This demonstration illustrates an advantage of soft robotics: They are systems in which simple types of actuation produce complex motion.biomimetic | mobile R obotics developed to increase the range of motions and functions open to machines, and to build into them some of the characteristics [including autonomous motion (1-3), adaptability to the environment (4-7), and capability of decision making (8, 9)] of animals, particularly animals with skeletons. Most mobile robots are built with hard materials (hard robots), either by adding treads or wheels (10, 11) to conventional machines to increase their mobility, or by starting with conceptual models based on animals [e.g., Big Dog (12) and many others (13-15)], and replicating some of their features in hard structures. Although robotics has made enormous progress in the last 50 years, hard robots still have many limitations. Some of these limitations are mechanical, and include instability when moving in difficult terrain; some have to do with the ranges of motions afforded by actuators and structures (e.g., metal rods, mechanical joints, and electric motors); some stem from the complexity in control (especially when handling materials and structures that are soft, delicate, and complex in shape). Hard robots fabricated from metals are also often heavy and expensive, and thus are not suitable for some applications.New classes of robots may thus find uses in applications where conventional hard robots are unsuitable. We are interested in a unique class of robots: That is, soft robots fabricated in materials (predominantly elastomeric polymers) that do not use a rigid skeleton to provide mechanical strength. The objective of this work is to demonstrate a soft robot that requires only simple design and control to generate mobility. In this demonstration, we begin to address some of the issues that have limited the development of soft robots. Instead of basing this and other designs on highly evolved animals as models, we are using simpler organisms [e.g., worms (16) and starfish (17)] for inspiration. These organisms, ones without internal skeletons, suggest designs that are simpler to make and are less expensive than conventional hard robots, and that may, in some respects, be more capable of complex motions and functions. Simple, inexpensive systems will probably not replace more complex and expensive ones, but may have different...

Chemo-responsive, self-oscillating gels that undergo biomimetic communication

“…Research on synthetic auto-chemotaxing particles is still in its infancy, but recent advances 2,3 point to promising efforts in the creation of mechanically compliant materials that appear to communicate and effectively collaborate. Separate advances in automated responses for self-healing polymeric structures 31,32 and actuating structures 33 have achieved impressive macroscopic motion with nonfunctional polymers, which may eventually be augmented by use of functional, autochemotactic materials. Thus, these advances in responsive gels can pave the way for the design of the next generation of responsive, interactive ''soft robots.''…”

Robotic Tentacles with Three‐Dimensional Mobility Based on Flexible Elastomers

“…[6][7][8] The flexibility of soft actuators offers potentially useful approaches to problems in robotics, and to the design of actuators, grippers, and other soft machines. They can also take advantage of often highly non-linear responses to actuation to accomplish, relatively simply, types of complex motions and tasks that are more difficult to accomplish using hard machines and conventional controllers.…”

“…[6,9] The mobility of the soft robotic structures with which we have worked-structures actuated by the expansion of elastomeric pneumatic networks-have been limited to a single bending mode in the direction defined by the anisotropy of the pneumatic expansion. [6,7] We wished to improve the motion capabilities of these systems, and specifically to fabricate entirely soft robotic actuators with three-dimensional (3D) motion, low cost, and simplicity of control.…”

“…[17,18] Our previous work in soft robotics has demonstrated the use of pneumatic networks (PneuNets)-fabricated in elastomeric materials using soft lithographic techniques highly developed in microfluidics-to serve as soft robotic actuators. [6,7] Here we use these systems to generate new types of elastomeric soft actuators that allow 3D motion. This type of actuator is simple to fabricate, flexible in its operation, and inexpensive.…”

Toward Perceptive Soft Robots: Progress and Challenges

“…In the last decade, soft robotics has been rising up as an emerging research topic,1 with some remarkable achievements such as: universal jamming gripper,2 multigait soft robot,3 worm robot,4 octopus robot,5 fully integrated soft octobot,6 growth robot,7 soft multilocomotion microrobot,8 and so on. Building on intrinsically soft materials or compliant mechanisms, soft robots are rapidly opening new possibilities for typical robotic tasks (e.g., grasping, dexterous manipulation, and locomotion), and also adding new robotic abilities that were unthinkable before,9 like morphing and self‐healing.…”