Where rigid robots run into limits
Traditional robots are built from rigid links connected by joints, a design philosophy well suited to tasks that reward precision and repeatability, like welding a car chassis to a tolerance of a fraction of a millimeter. But that same rigidity becomes a liability the moment a task involves uncertainty about shape, size, or fragility. A rigid gripper calibrated to pick up one object size will crush a softer object or fail to grip an irregular one, and a rigid frame can't meaningfully deform to fit through a gap narrower than itself.
Soft robotics approaches these problems from the opposite direction, building robots, or robot components, from materials that bend, stretch, and deform, rather than fighting against deformation. Instead of relying on precise rigid geometry, a soft robot can conform to whatever it encounters, which is exactly the behavior needed for tasks involving fragile, irregular, or unpredictable objects and environments. This overlaps in places with the mechanics covered in grippers and actuator courses, but the soft robotics angle is specifically about designing with compliance and deformation as the core strategy, not an exception to be engineered around.