Soft actuators in surgical robotics: a state-of-the-art review

Soft surgical robots represent a groundbreaking innovation in the field of medical technology. These robots utilize soft, deformable materials to navigate and interact with delicate structures inside the human body, such as organs and blood vessels, with enhanced safety. They have the potential to transform healthcare by expanding the capabilities of minimally invasive surgeries, targeted drug delivery, and precise diagnostics. They can also reduce patient discomfort, recovery times, and the risk of complications, infections, and accidental injuries. The key to the functionality of soft surgical robots lies in their actuation mechanisms. Various actuation methods have been developed, including pneumatic, magnetic, tendon-driven, smart materials (like shape memory alloys, dielectric elastomer actuators, and ionic polymer-metal composites), and hybrid combinations of these mechanisms. Each actuator type offers unique advantages and challenges, making the selection of the right actuation solution a complex task. This review paper aims to provide a comprehensive understanding of these soft actuation mechanisms and their applications in surgical robotics. It delves into the current state of the art in various applications, from endoscopes and catheters to cardiac support devices, bioinspired inchworm robots, and more. While significant progress has been made in the field of soft actuators for surgical robotics, this paper identifies several challenges that must still be overcome to effectively apply these innovations in real-life surgical procedures on human patients.