Low-Cost and Easy-to-Build Soft Robotic Skin for Safe and Contact-Rich Human–Robot Collaboration

Although many soft robotic skins have been introduced, their use has been hindered due to practical limitations, such as difficulties in manufacturing, poor accessibility, and cost inefficiency. To solve this, we present a low-cost, easy-to-build soft robotic skin utilizing air-pressure sensors and 3D-printed pads. In our approach, we utilized digital fabrication and robot operating system (ROS) to facilitate the creation and use of the robotic skin. The skin pad was fabricated by printing thermoplastic urethane (TPU) and postprocessed with an organic solvent to secure air-tightness. Each pad consists of a TPU shell and infill, so the internal air-pressure changes in response to tactile stimuli, such as force and vibration. The internal pressure is measured and processed by a microcontroller and transmitted to the host computer via a serial bus. We conducted experiments to investigate the characteristics of the skin pads, and the results showed that the developed robotic skins are capable of perceiving interaction force and dynamic stimuli. Finally, we developed the dedicated soft robotic skins for our custom robot designed in-house, and demonstrated safe and intuitive physical human–robot interaction.