3D Printed Soft Actuators for a Legged Robot Capable of Navigating Unstructured Terrain
Soft robotics is a rapidly developing field that is changing the way we perceive automated systems. Soft robots deform continuously along their bodies as opposed to at discrete joints like traditional rigid robots. In this work we demonstrated the use of multi-material 3D printing to fabricate a four-legged walking robot with bellowed soft legs. The robot is powered by pressurized air and is able to navigate a variety of terrain. This design is a step towards the development of a mobile soft system for applications including monitoring in hazardous environments and search-and-rescue operations.
Drotman D., Jadhav S., Karimi M., deZonia P., Tolley M. T., (2017) "3D Printed Soft Actuators for a Legged Robot Capable of Navigating Unstructured Terrain", Int. Conf. on Robotics and Automation (ICRA), Singapore, May 2017.
Swimming Soft Robot with Fluid Electrode Dielectric Elastomer Actuation
Submersible robots are finding ever-increasing uses in search and rescue, environmental monitoring, and defense applications. Artificial muscles made out of dielectric elastomer actuators (DEAs) provide an attractive choice for driving submersible robotics based on their high energy density, light weight, and efficiency. One challenge for most DEAs is that that they require conductive electrodes that are made out of materials that are challenging to pattern and/or add stiffness to the devices. Our solution is to use water as our conductive electrodes, which simplifies the design of our artificial muscles compared to alternative designs, allowing us to make lightweight, environmentally friendly, compliant electrodes for soft, underwater robots.
Christianson C., Goldberg N. , Cai S., Tolley M. T., (2017) “Fluid electrodes for submersible robotics based on dielectric elastomer actuators,” SPIE Electroactive Polymer Actuators and Devices (EAPAD) XIX, Portland OR, March 2017.
Soft robotic glove for kinesthetic haptic feedback in virtual reality
Current virtual reality technologies rely heavily on visual and audio feedback as a form of sensory feedback. Most existing wearable haptic devices use vibrating motors, which are unable to provide force feedback, or rigid linkage devices which are bulky and inflexible. We address this issue with a wearable soft robotic glove capable of safely applying forces to the fingers of the user. The glove design includes a soft exoskeleton actuated by Mckibben muscles that are controlled using a custom fluidic control board. The result is a haptic glove that is compliant, compact and unintimidating. We demonstrated its application with a virtual reality environment that simulates playing the piano and received positive preliminary feedback from users. This glove represents a step toward developing natural 3D user interfaces by replacing the existing wand controllers.
Jadhav S., Kannanda V., Kang B., Tolley M. T., Schulze J. P., (2017) "Soft robotic glove for kinesthetic haptic feedback in virtual reality environments", IS&T Electronic Imaging: The Engineering Reality for Virtual Reality proceedings, IS&T Springfield VA, 2017.
Soft Robotics - Untethered Quadruped
While robots are traditionally designed to be as rigid as possible so that they can be easily modeled and precisely controlled, nature suggests an alternative approach. Plants and animals exhibit a large range of rigidity, but most are much softer than engineering materials such as steel or injection-molded plastics. Not only does nature tolerate this softness but it embraces it, achieving feats of adaptability and agility unrivaled in engineered systems. The field of Soft Robotics seeks to draw inspiration from natural systems such as cephalopods, to develop a new breed of robots that is more adaptable to unknown environments and safe to work with. The Bioinspired Robotics and Design Lab seeks to develop untethered soft robots with integrated power and control systems. The following video describes a resilient, untethered soft robot developed by Prof. Tolley and collaborators during his Postdoctoral Fellowship at Harvard University.
Fabrication by Folding
Nature frequently employs folding for fabrication. From very small scales where proteins are folded from linear strings of amino acids, to larger scales where organs are folded from sheets of cells and plant leaves and insect wings deploy by folding or unfolding. The ancient Japanese art of origami also uses folding to form three dimensional structures from sheets of material. Inspired by these examples, we seek to develop new approaches to the fabrication of engineered structures and robotic systems, employing folding for assembly or deployment. The following video describes previous work which demonstrates a walking robot fabricated as a flat sheet that deploys itself by folding and is able to immediately begin operation.