Currently, pneumatic soft actuators are widely used due to their impressive adaptability, but they still face challenges for more extensive practical applications. One of the primary issues is the bulky and noisy air compressors required to generate air pressure. To circumvent this critical problem, this work proposes a new type of air pressure source, based on the vapor pressure at the gas-liquid equilibrium to replace conventional air pumps. Compared with the previous phase transition method, this approach gains advantages such as generating gas even at low temperatures (instead of boiling point), more controllable gas output, and higher force density (since both ammonia and water contribute to the gas pressure). This work built mathematical models to explain the mechanism of converting energy to output action force from electrical energy and found the aqua ammonia system is one of the optimal choices. Multiple prototypes were created to demonstrate the capability of this method, including a pouch actuator that pushed a load 20,555 times heavier than its dead weight. Finally, based on the soft actuator, an untethered crawling robot was implemented with onboard batteries, showing the potentially extensive applications of this methodology.

中文翻译：

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无泵气动执行器，由氨水气液平衡的蒸气压驱动。


目前，气动软致动器因其令人印象深刻的适应性而被广泛使用，但它们仍然面临着更广泛的实际应用的挑战。主要问题之一是产生气压所需的笨重且嘈杂的空气压缩机。为了规避这一关键问题，这项工作提出了一种新型的气压源，基于气液平衡时的蒸气压来取代传统的气泵。与以前的相变方法相比，这种方法具有即使在低温（而不是沸点）下也能产生气体、更可控的气体输出和更高的力密度（因为氨和水都会产生气体压力）等优点。这项工作建立了数学模型来解释将能量转化为电能输出作用力的机制，并发现水氨系统是最佳选择之一。创建了多个原型来演示这种方法的能力，包括一个将负载推至其自重 20,555 倍的造袋致动器。最后，基于软致动器，实现了一个带有机载电池的无系绳爬行机器人，展示了该方法的潜在广泛应用。