A Perspective on Miniature Soft Robotics: Actuation, Fabrication, Control, and Applications

Soft robotics enriches the robotic functionalities by engineering soft materials and electronics toward enhanced compliance, adaptivity, and friendly human machine. This decade has witnessed extraordinary progresses and benefits in scaling down soft robotics to small scale for a wide range of potential and promising applications, including medical and surgical soft robots, wearable and rehabilitation robots, and unconstructed environments exploration. This perspective highlights recent research efforts in miniature soft robotics in a brief and comprehensive way in terms of actuation, powering, designs, fabrication, control, and applications in four sections. Section 2 discusses the key aspects of materials selection and structural designs for small-scale tethered and untethered actuation and powering, including fluidic actuation, stimuli-responsive actuation, and soft living biohybrid materials, as well as structural forms from 1D to 3D. Section 3 discusses the advanced manufacturing techniques at small scales for fabricating miniature soft robots, including lithography, mechanical self-assembly, additive manufacturing, tissue engineering, and other fabrication methods. Section 4 discusses the control systems used in miniature robots, including off-board/onboard controls and artificial intelligence-based controls. Section 5 discusses their potential broad applications in healthcare, small-scale objects manipulating and processing, and environmental monitoring. Finally, outlooks on the challenges and opportunities are discussed.