While doing a recent search on up-and-coming technologies and cutting-edge science, I stumbled upon some YouTube videos of soft robots, and subsequently found the website of OtherLab. Other Lab is a collective of scientists and inventors involved in a number of projects, including proof-of-concept mechatronics that might be useful in building functionally adaptive and intelligent machines. In this post, I will review a number of videos from their YouTube channel.
Similar to a number of physiological pumping processes, here is a peristaltic pump design built by the lab. The process of peristalsis is the main actuation process in smooth and skeletal muscle systems. Peristalsis allows for symmetrical displacements of the muscular surface that occurs in waves and moves fluids through the body. The gastrointestinal tract and four- chambered heart are two examples of this. This pump design, optimized for modeling muscular output during joint flexion, is a key component of OtherLab's pneubotic machines.
This video shows the strategy OtherLab is using to design their soft robots and other creations. To fabricate motors, robots, and other mechanical things OtherLab specializes in, they use a CNC (computer numerical control) machine technique called "nesting". I have discussed rapid prototyping in earlier posts, particularly as it relates to building physical models. In this case, OtherLab is using a technique called nesting. In fabrication programming (as opposed to computational programming), nesting refers to the laying out of multiple parts, some entirely contained within others, on a single surface. This allows for dynamic nesting, which allows for the management of many part sizes and shapes simultaneously. A complex layer is then created, which is subsequently cut and incorporated into a technological design.
Pneubot stands for "pneumatic robot", or a robot that is actuated by pneumatic technology. A pneumatic technology involves the use of compressed air to drive mechanical motion. The compressed air can be moved through soft, balloon-like tubes, which allows for both rigidity (when filled) and flexibility (when decompressed or empty). In this video, an elephant-shaped pneubot is used to demonstrate the level of motor control allowed using this technology. The OtherLab is developing this technology in concert with Manu Prakash's lab at Stanford and DARPA's Maximum Mobility and Manipulation program.
In this video, a soft-bodied "crawler" robot moves across a flat tabletop and does the limbo, demonstrating the flexibility of gait and movement achievable with soft robot bodies. This "crawler" bot is another instance of the pneubot, just scaled down considerably. The idea of a soft-bodied robot is generally new, and can be applied to a number of medical and industrial problems.
Pneumatics are not only used to build selectively compliant skeletons for robots. They can also be used as braces and muscles, exhibiting rigidity when required. In this video, a knee brace is demonstrated that can force a human knee joint to full extension.
According to the embodiment school of thought, a robot's body and brain are dependent on each other, and interact accordingly. The soft robot examples do not come with an on-board brain. Fully autonomous control (or the robot's ability to control its own beahvior) is a "holy grail" of robotics, as it allows for both remote and on-the-fly operation that does not rely on human input. In this example, the OtherLab group demonstrates autonomous control in a model aircraft, which can maintain a circular heading without external commands.
This is another example of autonomous control, this time in the form of actuation. This form of autonomous actuation mimics tropic behaviors observed in many plants and animals. The mirror array shown in the picture/video moves with the sun (e.g. heliostatic), or in this case another light source that moves around the environment with respect to the stationary mirror array. This kind of actuation is currently used in very large solar panel arrays and solar furnaces.