Most robots today are designed to be either as rigid as possible (e.g. industrial Kuka robot arms, Boston Dynamics' Spot and Atlas, etc), or they are fully soft (e.g. Soft Robotics' mGrip). In contrast, the morphological designs we see in nature are fundamentally different. Vertebrates, for example, feature a rigid skeletal system that is complemented by various types of soft tissues (articular cartilage and ligaments, muscles and tendons, soft pads that modulate the forces arising from physical interactions with external objects, etc). Indeed, structural compliance arising from the strategic use of soft materials is an integral part of the design of every biomechanical system, defining the performance, efficiency and robustness of its movements. In our quest to create robots that are as skilled and adaptable as their living counterparts, developing designs that seamlessly integrate soft and rigid materials is therefore of utmost importance. Nevertheless, despite decades of research, such hybrid soft-rigid designs are still out of reach.
In defining how future generations of robots will be made, additive manufacturing (AM) technologies will play a pivotal role. This is because they allow us to create designs of unparalleled geometric complexity using a constantly expanding range of materials. Indeed, if past developments are an indication, within the next decade we will be able to fabricate physical structures that approach, at least at the macro scale, the functional sophistication of their biological counterparts. However, while this unprecedented capability enables fascinating opportunities, it also leads to an explosion in the dimensionality of the space that must be explored during the design process. As AM technologies keep evolving, the gap between "what we can produce" and "what we can design" is therefore rapidly growing.
To effectively leverage the extraordinary design possibilities enabled by AM, our project aimed to develop the computational and mathematical foundations required to study a fundamental scientific question: how are physical deformations, mechanical movements and overall functional capabilities governed by geometric shape features, material compositions and the design of compliant actuation systems? By enabling computers to reason about this question, our work has established new ways to algorithmically create digital designs that can be turned into mechanical lifeforms at the push of a button.
