Contents I. Introduction
Recent research on mobile robots has focused on increasing their adaptability to unpredictable and unstructured environments for various applications in which they could replace humans, such as search and rescue missions during disasters and at military sites [1]–[4], repetitive transportation tasks in warehouses [5], [6], and in the delivery of goods to multiple locations [7], [8]. For these types of tasks, mobile robots must be highly robust, in addition to adaptive to harsh environments; i.e., they should be able to handle changes in moisture, temperature, and magnetic/electromagnetic fields [9], [10]. To ensure both adaptability and robustness, soft materials and structures have recently been used to build robots. For example, soft materials were fused with commercial motors in order to realize different types of driving locomotion [11]–[13]. Furthermore, due to its simplicity and ease of use in terms of implementation when combined with soft materials [14], pneumatics has been widely employed as one of the key actuation mechanisms. Pneumatic actuators provide relatively high force-to-weight ratios and durability [15].
