Natural systems, however, often match or exceed the performance of robotic systems with deformable bodies.
Soft robots provide an opportunity to bridge the gap between machines and people. In contrast to hard-bodied robots, soft robots have bodies made out of intrinsically soft and/or extensible materials (for example, silicone rubbers) that can deform and absorb much of the energy arising from a collision.
The key challenge for creating soft machines that achieve their full potential is the development of controllable soft bodies using materials that integrate sensors, actuators and computation, and that together enable the body to deliver the desired behaviour.
For the body of a soft robot to achieve its potential, facilities for sensing, actuation, computation, power storage and communication must be embedded in the soft material, resulting in smart materials. In addition, algorithms that drive the body to deliver the desired behaviours are required.
The segments of a soft robot are usually actuated in one of two ways (Fig. 4): variable length tendons (in the form of tension cables23 or shape-memory alloy actuators24) may be embedded in soft segments, to achieve, for example, robotic octopus arms (Fig. 3f ); or pneumatic actuation is used to inflate channels in a soft material and cause a desired deformation.
Since energy is typically most readily stored in electrical form, and computation is usually done on electronic circuits, it may be more efficient to directly use electrical potential to actuate soft robots.
Researchers have manufactured complex soft-robotic systems by taking advantage of rapid and adaptable fabrication techniques66, including multimaterial 3D printing67, shape deposition manufacturing (SDM)68 and soft lithography69. These techniques can be combined to create composites with heterogenous materials (for example, rubber with different stiffness moduli), embedded electronics and internal channels for actuation31,70.
An understanding of the working principles and control of soft organisms (such as the octopus) has led to a model for the control of soft robots.
A limitation of existing approaches to solving the inverse-kinematics problem for linear soft bodies (for example, arms) is that currently neither the whole body, nor the pose of the end effector (which may be important for manipulation, sensing, and so on), are not considered in the solution. Autonomous obstacle avoidance and movement through a confined environment are difficult without a computational solution to the inverse-kinematics problem that is aware of the whole body of the robot in space.
Soft systems have a natural advantage over rigid robots in grasping and manipulating unknown objects because the compliance of soft grippers allows them to adapt to a variety of objects with simple control schemes.
Harvard Biodesign Lab We’ve seen videos of their projects before, and I found their website to be educational.
DIY Soft Robotic Gripper This guy seems to be a hobbyist that makes soft robots for fun. To create the gripper, you only need 3 materials: hot glue, cardboard, and rubber. To actually operate it, you also need a squeeze bulb and curling ribbon.