  Soft robots are made of compliant materials that perform their tasks by
deriving motion from elastic deformations. They are used in various
applications, e.g., for handling fragile objects, navigating sensitive/complex
environments, etc., and are typically actuated by Pneumatic/hydraulic loads.
Though demands for soft robots are continuously increasing in various
engineering sectors, due to the lack of systematic approaches, they are
primarily designed manually. This paper presents a systematic density-based
topology optimization approach to designing soft robots while considering the
design-dependent behavior of the actuating loads. We use the Darcy law with the
conceptualized drainage term to model the design-dependent nature of the
applied pressure loads. The standard finite element is employed to evaluate the
consistent nodal loads from the obtained pressure field. The robust topology
optimization formulation is used with the multi-criteria objective. The success
of the presented approach is demonstrated by designing a member/soft robot of
the pneumatic networks (PneuNets). The optimized member is combined in several
series to get different PneuNets. Their CAD models are generated, and they are
studied with high-pressure loads in a commercial software. Depending upon the
number of members in the PneuNets, different output motions are noted.
