New soft robot has optimized swimming properties

Researchers from the Singapore University of Technology and Design have combined two different approaches to create an integrated workflow to develop novel automated processes for designing and fabricating custom soft robots. The method the team developed can be applied to other kinds of soft robots allowing mechanical properties to be tailored in an easy and accessible manner. Soft robots are a major area of study all around the world because the soft robots are particularly good at working in environments with humans and are more flexible.

Soft robots are inspired by the flexible forms of living organisms and have wide applications for sensing, movement, object grasping and manipulation, and more. Typically, soft robots are fabricated using manual casting techniques, which limits the complexity and geometries researchers can achieve. For the new robot, the team used 3D printing or additive manufacturing to extrude various material inks in a supportive matrix.

The process is particularly well-suited for fabricating soft robots made from multiple materials or composites. The team used topology optimization to ensure their soft robots are optimally designed using mathematical models to design bespoke structures within a specific set of constraints. Optimizing the two steps into a single framework allows the authors to develop an integrated workflow for creating custom soft robots while minimizing potential errors.

In their study, the team used a swimming autonomous robot inspired by batoids. The workflow began by defining the robot's fin geometry before topology optimization was used to generate the design structure with the desired properties within prescribed material and motion constraints. The design was transformed into code read by the custom-built 3D printer that fabricates the robot.

The soft robots were designed to survive a marine environment, and the approach focused on tailoring the fin composition to assess how the changes can impact the robots swimming performance. Researchers found after optimization that the optimized composite fins were 50 percent faster than a counterpart with traditionally casted soft fins. It was also slightly faster than a robot featuring a hard fin.