https://www.oxfordmartin.ox.ac.uk/downloads/academic/The_Future_of_Employment.pdf

The future of employment: How susceptible are jobs to computerisation?

Conventionally, engineers have employed rigid materials to fabricate precise, predictable robotic systems, which are easily modelled as rigid members connected at discrete joints. Natural systems, however, often match or exceed the performance of robotic systems with deformable bodies. Cephalopods, for example, achieve amazing feats of manipulation and locomotion without a skeleton; even vertebrates such as humans achieve dynamic gaits by storing elastic energy in their compliant bones and soft tissues. Inspired by nature, engineers have begun to explore the design and control of soft-bodied robots composed of compliant materials. This Review discusses recent developments in the emerging field of soft robotics.

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Design, fabrication and control of soft robots

An untethered, entirely soft robot is designed to operate autonomously by combining microfluidic logic and hydrogen peroxide as an on-board fuel supply. Soft robotics have so far necessarily included some 'hard' or metallic elements, in particular in the form of batteries or wiring, to connect them to an external power source. Additionally, external wiring tethering them to a power source places limits on the autonomy of such robots. Now Jennifer Lewis and colleagues have combined a 3D-printed soft polymeric robot with microfluidic logic and hydrogen peroxide as an onboard fuel to produce an eight-armed robot — an 'octobot' — that actuates its arms, without the incorporation of any hard structures. The hydrogen peroxide decomposes in the presence of a platinum catalyst to produce oxygen and a volumetric expansion that fills bladders embedded within the arms of the octobot. The design of the fuel reservoirs, microfluidic channels and vents to release the gas means that two sets of arms actuate cyclically. Soft robots possess many attributes that are difficult, if not impossible, to achieve with conventional robots composed of rigid materials1,2. Yet, despite recent advances, soft robots must still be tethered to hard robotic control systems and power sources3,4,5,6,7,8,9,10. New strategies for creating completely soft robots, including soft analogues of these crucial components, are needed to realize their full potential. Here we report the untethered operation of a robot composed solely of soft materials. The robot is controlled with microfluidic logic11 that autonomously regulates fluid flow and, hence, catalytic decomposition of an on-board monopropellant fuel supply. Gas generated from the fuel decomposition inflates fluidic networks downstream of the reaction sites, resulting in actuation12. The body and microfluidic logic of the robot are fabricated using moulding and soft lithography, respectively, and the pneumatic actuator networks, on-board fuel reservoirs and catalytic reaction chambers needed for movement are patterned within the body via a multi-material, embedded 3D printing technique13,14. The fluidic and elastomeric architectures required for function span several orders of magnitude from the microscale to the macroscale. Our integrated design and rapid fabrication approach enables the programmable assembly of multiple materials within this architecture, laying the foundation for completely soft, autonomous robots.

/pdf/an-integrated-design-and-fabrication-strategy-for-entirely-4p2oed8f3w.pdf

An integrated design and fabrication strategy for entirely soft, autonomous robots

Soft robots actuated by infl ation of a pneumatic network (a “pneu-net”) of small channels in elastomeric materials are appealing for producing sophisticated motions with simple controls. Although current designs of pneu-nets achieve motion with large amplitudes, they do so relatively slowly (over seconds). This paper describes a new design for pneu-nets that reduces the amount of gas needed for infl ation of the pneu-net, and thus increases its speed of actuation. A simple actuator can bend from a linear to a quasicircular shape in 50 ms when pressurized at Δ P = 345 kPa. At high rates of pressurization, the path along which the actuator bends depends on this rate. When infl ated fully, the chambers of this new design experience only one-tenth the change in volume of that required for the previous design. This small change in volume requires comparably low levels of strain in the material at maximum amplitudes of actuation, and commensurately low rates of fatigue and failure. This actuator can operate over a million cycles without signifi cant degradation of performance. This design for soft robotic actuators combines high rates of actuation with high reliability of the actuator, and opens new areas of application for them.

/pdf/pneumatic-networks-for-soft-robotics-that-actuate-rapidly-4epg8a3njg.pdf

Pneumatic Networks for Soft Robotics that Actuate Rapidly

Light- and ink-based three-dimensional (3D) printing methods allow the rapid design and fabrication of materials without the need for expensive tooling, dies or lithographic masks. They have led to an era of manufacturing in which computers can control the fabrication of soft matter that has tunable mechanical, electrical and other functional properties. The expanding range of printable materials, coupled with the ability to programmably control their composition and architecture across various length scales, is driving innovation in myriad applications. This is illustrated by examples of biologically inspired composites, shape-morphing systems, soft sensors and robotics that only additive manufacturing can produce.

Printing soft matter in three dimensions

Gripping and holding of objects are key tasks for robotic manipulators. The development of universal grippers able to pick up unfamiliar objects of widely varying shape and surface properties remains, however, challenging. Most current designs are based on the multifingered hand, but this approach introduces hardware and software complexities. These include large numbers of controllable joints, the need for force sensing if objects are to be handled securely without crushing them, and the computational overhead to decide how much stress each finger should apply and where. Here we demonstrate a completely different approach to a universal gripper. Individual fingers are replaced by a single mass of granular material that, when pressed onto a target object, flows around it and conforms to its shape. Upon application of a vacuum the granular material contracts and hardens quickly to pinch and hold the object without requiring sensory feedback. We find that volume changes of less than 0.5% suffice to grip objects reliably and hold them with forces exceeding many times their weight. We show that the operating principle is the ability of granular materials to transition between an unjammed, deformable state and a jammed state with solid-like rigidity. We delineate three separate mechanisms, friction, suction, and interlocking, that contribute to the gripping force. Using a simple model we relate each of them to the mechanical strength of the jammed state. This advance opens up new possibilities for the design of simple, yet highly adaptive systems that excel at fast gripping of complex objects.

/pdf/universal-robotic-gripper-based-on-the-jamming-of-granular-1lfy77b5w6.pdf

Universal robotic gripper based on the jamming of granular material

A soft, mobile, morphing robot is a desirable platform for traversing rough terrain and navigating into small holes. In this work, a new paradigm in soft robots is presented that utilizes jamming of a granular medium. The concept of activators (as opposed to actuators) is presented to jam and unjam cells that then modulate the direction and amount of work done by a single central actuator. A prototype jamming soft robot utilizing JSEL (Jamming Skin Enabled Locomotion) with external power and control is discussed and both morphing results and mobility (rolling) results are presented. Future directions for the design of a soft, hole traversing robot are discussed, as is the role and promises of jamming as an enabling technology for soft robotics.

/pdf/jsel-jamming-skin-enabled-locomotion-3vk7tzgs4v.pdf

JSEL: Jamming Skin Enabled Locomotion

This paper presents a new architecture in soft robotics that utilizes particulate jamming technology. A novel
concept of actuation is described that utilizes jamming technology to modulate the direction and magnitude of the
work performed by a single central actuator. Jamming "activators" modulate work by jamming and unjamming
(solidifying and liquifying) a granular medium coupled to a core actuator. These ideas are demonstrated in
the Jamming Skin Enabled Locomotion (JSEL) prototype which can morph its shape and achieve locomotion.
Next, a new actuator, denoted a Jamming Modulated Unimorph (JMU), is presented in addition to the JSEL
topology. The JMU uses a single linear actuator and a discrete number of jamming cells to turn the 1 degree of
freedom (DOF) linear actuator into a multi DOF bending actuator. Full characterization of the JMU actuator is
presented, followed by a concluding argument for jamming as an enabling mechanism for soft robots in general,
regardless of actuation technology.

Jamming as an enabling technology for soft robotics

A method for manipulating an object with a remote vehicle having a manipulator attached to a manipulator arm. The manipulator comprises a jamming or other phase change material in a housing. The method comprises pressing the manipulator housing to the object, activating the jamming or other phase change material to cause the manipulator to grasp the object, and moving one or more of the manipulator arm and the remote vehicle to manipulate the object.

Method and device for manipulating an object

A robotic joint assembly includes a first structural member, a second structural member, and a rolling flexure joint joining the first structural member to the second structural member to provide at least one degree of freedom between the first and second structural members. The rolling flexure joint includes first and second flexible hinge members each having one end secured to the first structural member and an opposing end secured to the second structural member. The first and second flexible hinge members cross one another between the first and second structural members.

Annan Michael Mozeika

Papers

Universal robotic gripper based on the jamming of granular material

JSEL: Jamming Skin Enabled Locomotion

Jamming as an enabling technology for soft robotics

Method and device for manipulating an object

Inflatable Robots, Robotic Components and Assemblies and Methods Including Same