Talk:Soft robotics

Proposed Edits to the Entire Soft Robotics Page
MTLE4470 grp3 HG (talk) 01:39, 27 April 2017 (UTC)

New Structure of Article

Contents: 1. Types and Designs 2. Biomimicry 3. Manufacturing 4. Control 5. Uses and Applications 6. International Journals 7. International Events 8. In popular culture 9. See also 10. References

Remove Aspects, Scientific community, and Technologies and techniques sections.

We plan to rewrite the introduction as follows: Soft Robotics is the specific sub-field of robotics dealing with constructing robots from highly compliant materials, similar to those found in living organisms. Similarly, soft robotics also draws heavily from the way in which these living organisms move and adapt to their surroundings. In contrast to robots built from rigid materials, soft robots allow for increased flexibility and adaptability for accomplishing tasks, as well as improved safety when working around humans. These characteristics allow for its potential use in the fields of medicine and manufacturing.

Types and Design section: The bulk of the field of soft robotics is based upon the design and construction of robots made completely from compliant materials, with the end result being similar to invertebrates like worms and octopi. The motion of these robots is difficult to model, as continuum mechanics apply to them, and they are sometimes referred to as continuum robots.Soft Robotics is the specific sub-field of robotics dealing with constructing robots from highly compliant materials, similar to those found in living organisms. Similarly, soft robotics also draws heavily from the way in which these living organisms move and adapt to their surroundings. In contrast to robots built from rigid materials, soft robots allow for increased flexibility and adaptability for accomplishing tasks, as well as improved safety when working around humans. These characteristics allow for its potential use in the fields of medicine and manufacturing. However, there exist rigid robots that are also capable of continuum deformations, most notably the snake-arm robot. Also, certain soft robotic mechanics may be used as a piece in a larger, potentially rigid robot. Soft robotic end effectors exist for grabbing and manipulating objects, and they have the advantage of producing a low force that is good for holding delicate objects without breaking them. Additionally, hybrid soft-rigid robots may be built using an internal rigid framework with soft exteriors for safety. The soft exterior may be multifunctional. It can act as both the actuators for the robot, similar to muscles in vertebrates, and as padding in case of a collision with a person.

Biomimicry section: Plant cells can inherently produce hydrostatic pressure due to a solute concentration gradient between the cytoplasm and external surroundings (osmotic potential). Further, plants can adjust this concentration through the movement of ions across the cell membrane. This then changes the shape and volume of the plant as it responds to this change in hydrostatic pressure. This pressure derived shape evolution is desirable for soft robotics and can be emulated to create pressure adaptive materials through the use of fluid flow. The following equation models the cell volume change rate: V dot = A*L_p(-deltaP + delta pi) (Equation 1) where V is the rate of volume change, Lp is the hydraulic conductivity of the material, delta π is the change in osmotic potential, delta P is the change hydrostatic pressure, and A is the cell membrane. Also, π is cRT, where c is the molecular concentration, R is the gas constant, and T is the temperature. This principle has been leveraged in the creation of pressure systems for soft robotics. These systems are composed of soft resins and contain multiple fluid sacs with semi-permeable membranes. The semi-permeability allows for fluid transport that then leads to pressure generation. This combination of fluid transport and pressure generation then leads to shape and volume change. Another biologically inherent shape changing mechanism is that of hygroscopic shape change. In this mechanism, plant cells react to changes in humidity. When the surrounding atmosphere has a high humidity, the plant cells swell, but when the surrounding atmosphere has a low humidity, the plant cells shrink. This volume change has been observed in pollen grains and pine cone scales.

Manufacturing section: Conventional manufacturing techniques, such as subtractive techniques like drilling and milling, are unhelpful when it comes to constructing soft robots as these robots have complex shapes with deformable bodies. Therefore, more advanced manufacturing techniques have been developed. Those include Shape Deposition Manufacturing (SDM), the Smart Composite Microstructure (SCM) process, and 3D multimaterial printing. SDM is a type of rapid prototyping whereby deposition and machining occur cyclically. Essentially, one deposits a material, machines it, embeds a desired structure, deposits a support for said structure, and then further machines the product to a final shape that includes the deposited material and the embedded part. Embedded parts include circuits, sensors, and actuators, and scientists have successfully embedded controls inside of polymeric materials to create soft robots, such as the Stickybot and the iSprawl. SCM is a process whereby one combines rigid bodies of carbon fiber reinforced polymer (CFRP) with flexible polymer ligaments. The flexible polymer act as joints for the skeleton. With this process, an integrated structure of the CFRP and polymer ligaments is created through the use of laser machining followed by lamination. This SCM process is utilized in the production of mesoscale robots as as the polymer connectors serve as low friction alternatives to pin joints. 3D printing can now produce shape morphing materials whose shape is photosensitive, thermally activated, or water responsive. Essentially, these polymers can automatically change shape upon interaction with water, light, or heat. One such example of a shape morphing material was created through the use of light reactive ink-jet printing onto a polystyrene target. Additionally, shape memory polymers have been rapid prototyped that comprise two different components: a skeleton and a hinge material. Upon printing, the material is heated to a temperature higher than the glass transition temperature of the hinge material. This allows for deformation of the hinge material, while not affecting the skeleton material. Further, this polymer can be continually reformed through heating.

Control Section: All soft robots require some system to generate reaction forces, to allow the robot to move in and interact with its environment. Due to the compliant nature of these robots, this system must be able to move the robot without the use of rigid materials to act as the bones in organisms, or the metal frame in rigid robots. However, several solutions to this engineering problem exist and have found use, each possessing advantages and disadvantages. One of these systems uses Dielectric Elastomeric Actuators (DEAs), materials that change shape through the application of a high-voltage electric field. These materials can produce high forces, and have high specific power (W/kg). However, these materials are best suited for applications in rigids robots, as they become inefficient when they do not act upon a rigid skeleton. Additionally, the high-voltages required can become a limiting factor in the potential practical applications for these robots. Another system uses springs made of shape-memory alloy. Although made of metal, a traditionally rigid material, the springs are made from very thin wires and are just as compliant as other soft materials. These springs have a very high force-to-mass ratio, but stretch through the application of heat, which is inefficient energy-wise. Pneumatic artificial muscles are yet another method used for controlling soft robots. By changing the pressure inside a flexible tube, it will act as a muscle, contracting and extending, and applying force to what it’s attached to. Through the use of valves, the robot may maintain a given shape using these muscles with no additional energy input. However, this method generally requires an external source of compressed air to function.

Uses and Applications Section: Soft robots can be implemented in the medical profession, specifically for invasive surgery. Soft robots can be made to assist surgeries due to their shape changing properties. Shape change is important as a soft robot could navigate around different structures in the human body by adjusting its form. This could be accomplished through the use of fluidic actuation. Soft robots may also be used for the creation of flexible exosuits, for rehabilitation of patients, assisting the elderly, or simply enhancing the user’s strength. A team from Harvard created an exosuit using these materials in order to give the advantages of the additional strength provided by an exosuit, without the disadvantages that come with how rigid materials restrict a person’s natural movement. Traditionally, manufacturing robots have been isolated from human workers due to safety concerns, as a rigid robot colliding with a human could easily lead to injury due to the fast paced motion of the robot. However, soft robots could work alongside humans safely, as in a collision the compliant nature of the robot would prevent or minimize any potential injury.MTLE4470 grp3 HG (talk) 01:37, 27 April 2017 (UTC)

inovation in 2020
''Engineers at the University of California San Diego have developed a new method... The innovation comes from rethinking the way soft robots are built: instead of figuring out how to add soft materials to a rigid robot body, the UC San Diego researchers started with a soft body and added rigid features to key components.'' Setenzatsu.2 (talk) 14:57, 11 April 2020 (UTC)