Robotic Muscle network

Robotics is a field of technology that has advanced rapidly recently, however most robots have remained very rigid and modular. They are built for one single task, and because of their rigidity, are unable to perform many functions outside of that task. Certain areas of research, such as soft robotics and metamaterials research, are looking to ways for robots to act in more fluid manners.

Metamaterials are materials that exhibit properties different than the material they are made from. In the case of robotic metamaterials, the goal is creating cells that can deform to different shapes on a small scale.  When these cells are connected in a larger grid, they have many more degrees of freedom. The overall robot can change its shape and size in a fluid way by changing its internal structure on a micro-scale. I was tasked with creating the body for the first prototype of the robotic cell.

The concept for the cell involved a body piece and 4 arms attached to springs to maintain some rigidity. Our cell would be able to take on 5 different shapes by extending or contacting each of its arms individually. The possible shape configurations for this robotic cell are shown below:

Our first design in CAD was mostly modular. We prototyped the body to include inputs for pneumatic tubes. We planned on attached elastic balloons to the end of each of these air channels. These balloons, when pneumatically actuated, would expand pushing the arms outward forming different cells shapes.

However, when it came to fabricating the prototype, we quickly realized that a modular design made assembly very difficult at small scales, especially attaching any sort of balloon to the pneumatic air chambers. Because of this, we opted to borrow the compliant buckling mechanism from our energy absorbing metamaterial project and use that mechanism as the method of arm extension and contraction into the cell. The first prototype in its 5 different shapes is shown below:

Assembly of the first prototype proved difficult, so instead of using laser cut hinges (made of white acrylic in the above photos, we decided to 3d print custom flexible springs which allowed for more uniform arm tension across the cell. The prototype with the newly designed springs is shown below.

This is the first of many prototypes to come for this project. Next steps involve incorporating the pneumatics into the current prototype. This would require the inclusion of separate air chambers for each arm indie the main body. These air chambers would attach to balloons, that would expend under each of the arms pushing them outwards to change the shape of the cell.

Once this has been included, computer software can be used to control the pneumatics of the cell. Many cells can be scaled down and attached together into a larger robot. This robot can use computer code to change each of the cells individually, resulting in a change in size and shape for the robot on a large scale. This type of robot could have numerous applications such as flexible factory arms, life animatronics in the themed entertainment, and robots that need to fit through oddly shaped holes or caves. This is the first step in prototype what could be standard technology in robots in the near future.