Robotics is nowadays facing emerging challenges, due to the need of designing and developing novel machines able to perform complex tasks in non-structured environments and to maintain their functionality for long periods (e.g. by self-repairing their structures). Wet machines and bio-hybrid robotic components recently emerged, opening the way towards the integration of living cells and tissues within artificial devices. This approach allows to exploit the unique features of living elements (high efficiency, self-healing capability, glucose-based powering, etc.), although several technological challenges must be faced before achieving this objective. This work aims at reporting the author’s achievements in the field of bio-hybrid systems (mainly concerning bio-hybrid actuation) and at highlighting that 2D and 3D biomaterials are key components of any bio-hybrid machine.