A review on soft pneumatic actuators with integrated or embedded soft sensors

Soft robotics has attained significant attention in recent years due to their infinite degree of freedom, adaptability, and safer interaction with humans and objects in various applications, such as robotics, biomedical devices, search and rescue operations, and wearable technology. However, the soft pneumatic actuator (SPA) is one of the most commonly and frequently utilized actuators in soft robotics due to its higher output at lower energy consumption. Further, an important development was the embedding/integration of soft and flexible sensors within the SPAs. This review article provides a comprehensive review of the frequently utilized SPA designs (McKibben, Pneu-Nets, and material jamming-based actuators), soft sensors (strain, pressure, temperature, tactile, flex, optical, and magnetic sensors), and SPAs with integrated or embedded soft sensors. Further, various emerging trends and breakthroughs in the SPA-sensors integration along with the limitations and challenges are discussed. Finally, it is found that there is an enormous amount of potential for revolutionizing the robotic and associated industries through the integration or embedding of soft sensors into SPAs. Even though there has been a lot of progress, there are still various challenges that need to be resolved and are provided in the future work section.