Foldable robots have been an active area of robotics research due to their high volume-to-mass ratio, easy packability, and shape adaptability. For locomotion, previously developed foldable robots have either embedded linear actuators in, or attached non-folding rotary motors to, their structure. Further, those actuators directly embedded in the structure of the folding medium all contributed to linear or folding motion, not to continuous rotary motion. On the macro-scale there has not yet been a folding continuous rotary actuator. This paper details the development and testing of the first macro-scale origami rotary motor that can be folded flat, and then unfurled to operate. Using corona discharge for torque production, the prototype motor achieved an expansion ratio of 2.5:1, reached a top speed of 1440 rpm when driven at -29 kV, and exhibited a maximum output torque over 0.15 mN m with an active component torque density of 0.04 Nm/kg.

翻译：可折叠机器人因其高体积质量比、易于包装和形状适应性而成为机器人研究的热点领域。在运动方式上，先前开发的可折叠机器人要么在其结构中嵌入线性致动器，要么附加非折叠旋转电机。此外，那些直接嵌入折叠介质结构中的致动器均用于产生线性或折叠运动，而非连续旋转运动。在宏观尺度上，目前尚未出现可折叠的连续旋转致动器。本文详细阐述并测试了首款可折叠至平面状态、展开后可运行的宏观尺度折纸旋转电机的开发过程。该原型电机利用电晕放电产生扭矩，实现了2.5:1的展开比，在-29 kV驱动电压下最高转速达1440 rpm，最大输出扭矩超过0.15 mN·m，其有效部件扭矩密度达到0.04 N·m/kg。