Department of Mechanical Engineering, McGill University, Montreal, Quebec, H3A 0C3, Canada.
Adv Sci (Weinh). 2021 Aug;8(15):e2100445. doi: 10.1002/advs.202100445. Epub 2021 Jun 1.
Rapid motion in soft pneumatic robots is typically achieved through actuators that either use a fast volume input generated from pressure control, employ an integrated power source, such as chemical explosions, or are designed to embed elastic instabilities in the body of the robot. This paper presents a bi-shell valve that can fast actuate soft actuators neither relying on the fast volume input provided by pressure control strategies nor requiring modifications to the architecture of the actuator. The bi-shell valve consists of a spherical cap and an imperfect shell with a geometrically tuned defect that enables shell snapping interaction to convert a slowly dispensed volume input into a fast volume output. This function is beyond those of current valves capable to perform fluidic flow regulation. Validated through experiments, the analysis unveils that the spherical cap sets the threshold of the snapping pressure along with the upper bounds of volume and energy output, while the imperfect shell interacts with the cap to store and deliver the desired output for rapid actuation. Geometry variations of the bi-shell valve are provided to show that the concept is versatile. A final demonstration shows that the soft valve can quickly actuate a striker.
使用压力控制产生的快速体积输入的致动器，采用化学爆炸等集成电源，或设计成在机器人主体中嵌入弹性不稳定性。本文提出了一种双壳阀，它可以快速驱动软致动器，既不依赖于压力控制策略提供的快速体积输入，也不需要对致动器的结构进行修改。双壳阀由一个球形帽和一个具有几何调谐缺陷的不完美壳组成，该缺陷使壳的突然破裂相互作用能够将缓慢分配的体积输入转换为快速体积输出。这种功能超出了当前能够进行流体流量调节的阀的功能。通过实验验证，分析表明球形帽与不完美壳一起设定了突然破裂压力的阈值，以及体积和能量输出的上限，而不完美壳与帽相互作用以存储和提供快速致动所需的输出。提供了双壳阀的几何形状变化，以表明该概念具有多功能性。最后一个演示表明，软阀可以快速驱动撞针。
