Soft Robotics: Biological Inspiration, State of the Art, and Future Research

Abstract

Traditional robots have rigid underlying structures that limit their ability to interact with their environment. For example, conventional robot manipulators have rigid links and can manipulate objects using only their specialised end effectors. These robots often encounter difficulties operating in unstructured and highly congested environments. A variety of animals and plants exhibit complex movement with soft structures devoid of rigid components. Muscular hydrostats (e.g. octopus arms and elephant trunks) are almost entirely composed of muscle and connective tissue and plant cells can change shape when pressurised by osmosis. Researchers have been inspired by biology to design and build soft robots. With a soft structure and redundant degrees of freedom, these robots can be used for delicate tasks in cluttered and/or unstructured environments. This paper discusses the novel capabilities of soft robots, describes examples from nature that provide biological inspiration, surveys the state of the art and outlines existing challenges in soft robot design, modelling, fabrication and control.

Elastomeric Origami: Programmable Paper‐Elastomer Composites as Pneumatic Actuators

“…Robots used for performing delicate tasks (e.g., surgery [1,2] ) can be flexible in their movement, but are quite specialized. Airborne robots (e.g., unmanned and autonomous air vehicles) are highly evolved, but do not have to deal with the vagaries of rough terrain.…”

“…Many of the structures of hard robots are based on structures derived from the body plans of mammals (or parts of them). [1,7,8] Their skeletons are typically rigid, and electric motors (or sometimes hydraulic or pneumatic systems) provide actuation. [9,10] Muscle-a structure ubiquitous in nature-still has no real counterpart in materials science, robotics, or actuation, although there are examples of electromagnetic actuators and other useful structures (for example "air muscles") which have some muscle-like properties.…”

Simple or Complex Bodies? Trade-offs in Exploiting Body Morphology for Control

“…In terms of applications, the most relevant area where exploitation of morphology is and will be the key is probably robotics, and in particular soft robotics (see [2,40,41,49] and the first issue of the journal Soft Robotics [48]). "Soft" robots, with the robot Octopus (e.g., [29]) serving as a good representative, break the traditional separation of control and mechanics and exploit the morphology of the body and properties of materials to assist control as well as perceptual tasks.…”

Design, implementation and modelling of the single and multiple extensor pneumatic muscle actuators

“…This developing research field emphases on robots made of soft materials which increase the safety of human-robot interaction, and make the robot more compliance to its environment (Mutlu, Yildiz, Alici, Marc in het Panhuis, & Spinks, 2016;Pillsbury, Guan, & Wereley, 2016). The infinite number of freedom (DOF) is achievable by soft robots due to the bending capability of the soft actuator and as a result, a robot end effector can reach every point in the 3D workspace (Trivedi, Rahn, Kier, & Walker, 2008). Soft robots have a further positive over rigid robots, where they produce slight resistance to obstacles and can adapt to them.…”