Ultrafast Soft Actuators

Abstract

\n The quest for an advanced soft robotic actuator technology that is fast and can execute a wide range of application-specific tasks at multiple length scales is still ongoing. Here, we demonstrate a new design strategy leveraging the concepts of miniaturisation and fibre-reinforcement to realize high-speed inflatable actuators exhibiting diverse movements. To fabricate the designs, we employ a class of additive manufacturing technology called melt electrowriting. We demonstrate 3D printing of microfibre architectures on soft elastomers with precision at unprecedently small length scales, leading to miniaturised composite actuators with highly controlled deformation characteristics. We show that owing to their small dimensions and deterministically designed fibrous networks, our actuators require extremely low amounts of fluid to inflate. We demonstrate that actuators with a length of 10 to 15mm and an inner diameter 1mm can reach their full range of motion within ~\u200920ms without exploiting snapping instabilities or material non-linearities. We display the speed of our actuators by building an ultrafast, soft flycatcher.