Soft actuators provide an attractive means for locomotion, gripping, and deployment of those machines and robots used in biomedicine, wearable electronics, automated manufacturing, etc. In this study, we focus on the shape-morphing ability of soft actuators made of pneumatic networks (pneu-nets), which are easy to fabricate with inexpensive elastomers and to drive with air pressure. As a conventional pneumatic network system morphs into a single designated state, achieving multimodal morphing has required multiple air inputs, channels, and chambers, making the system highly complex and hard to control. In this study, we develop a pneu-net system that can change its shape into multiple forms as a single input pressure increases. We achieve this single-input and multimorphing by combining pneu-net modules of different materials and geometry, while harnessing the strain-hardening characteristics of elastomers to prevent overinflation. Using theoretical models, we not only predict the shape evolution of pneu-nets with pressure change but also design pneu-nets to sequentially bend, stretch, and twist at distinct pressure points. We show that our design strategy enables a single device to carry out multiple functions, such as grabbing-turning a light bulb and holding-lifting a jar.

中文翻译：

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单输入气动网络的顺序多模态变形。


软执行器为生物医学、可穿戴电子产品、自动化制造等领域使用的机器和机器人的运动、抓取和部署提供了一种有吸引力的手段。在这项研究中，我们重点关注由气动网络制成的软执行器的形状变形能力（ pneu-nets），很容易用廉价的弹性体制造并用气压驱动。由于传统的气动网络系统变形为单一指定状态，实现多模态变形需要多个空气输入、通道和室，使得系统高度复杂且难以控制。在这项研究中，我们开发了一种气动网络系统，当单个输入压力增加时，该系统可以将其形状改变为多种形式。我们通过组合不同材料和几何形状的气动网络模块来实现这种单输入和多变形，同时利用弹性体的应变硬化特性来防止过度膨胀。使用理论模型，我们不仅预测气动网随压力变化的形状演变，而且设计气动网在不同压力点顺序弯曲、拉伸和扭曲。我们表明，我们的设计策略使单个设备能够执行多种功能，例如抓取并转动灯泡和举起罐子。