Bioinspired ventral-groove fibers for volume-programmable pneumatic actuation

Pneumatic actuation plays a central role in soft robotics, with conventional systems relying on pressure-driven chamber deformation and closed-loop feedback for precise control. Here, we introduce bioinspired ventral-groove filamentary fibers that reframe pneumatic actuation from pressure-dominated chambers to volume-programmable fiber architectures, enabling previously unexplored robotic capabilities. Coupling microgroove unfolding with elastic expansion, these molecularly programmed fibers achieve reversible 400× area expansion at ultralow pressure (∼0.8 kPa) and scale from ∼100 μm to centimeter-scale diameters and tens of meters in length, supporting micro- to macro-scale robotic systems. We demonstrate responsive textile actuation through an everyday flotation garment with 20-m fibers seamlessly integrated into clothing. We also show a gripping approach with three capabilities: disturbance-robust high-precision grasping, conformal handling of fragile nerve-like filaments and delicate incense-ash cones, and open-loop operation that reduces reliance on sensory feedback. By establishing a volume-programmable actuation paradigm, this work paves the way for low-pressure pneumatic technologies in soft robotics and responsive textiles.