Manufacturing and Design of Inflatable Kirigami Actuators

Kirigami structures are human-made structures that enable the fabrication of stretchable structures from materials with limited stretching properties through the geometrical re-orientation of their features. But these structures are generally complex in shape with many edges which makes their precise fabrication difficult without the use of engineering manufacturing tools. Building a pneumatic artificial muscle making use of kirigami concepts would be useful as the structure could make use of the re-orientation of its features rather than just relying on the stretching or expansion of the structure, but the structure must remain airtight despite its complex shape which would result in air channels needing to be sealed along each edge of this structure. This letter introduces a simple three-step manufacturing method capable of manufacturing inflatable kirigami actuators with networks of air channels with a wide range of shapes. Three novel inflatable kirigami actuators designs are presented making use of this manufacturing process: parallel kirigami actuators, out-of-plane kirigami actuators and spiral kirigami actuators. These actuators are capable of contraction ratios far exceeding those of previous inflatable pneumatic artificial muscles and can be readily implemented as active electronic muscles. This manufacturing method for inflatable kirigami actuators opens the door to a wide range of new inflatable actuator designs and could lead to further optimized designs for wearable uses.