Large-deformation Peristaltic Actuators
Aim and Objectives
Large deformation actuators can be used to simulate biological functions such as peristaltic motion and the interaction of internal organs with their surroundings such as the esophagus, stomach, intestines and heart. In this project a soft-bodied actuator inspired by the principles of the muscular hydrostat will be used to test the performance of different catheters (sizes, shape, flexibility etc), to validate clinically significant hypotheses, and to examine the flow of organ contents. Mechatronic design principles will be applied in developing the bio-robotic actuation system. Novel drives (such as PneuNet technique) and control methods (such as data-driven learning control) will be developed to make the actuator useful for various medical purposes.
We also plan to develop a theoretical foundation for the dynamics and control of soft-bodied robots comprising nervous units, actuation, sense and skeletal functions embodied in a single body. Irrespective of the form of drives and materials used, they will be soft and deformable, actuated, sensed and controlled in distributed manner, and of a potentially infinite number of degrees of freedom.
The research questions for soft-bodied robotics include how to describe the motion of such a robot (forward problem), find the actuation required for the prescribed motion (inverse problem), generate the distributed actuation (motion planning) and accomplish the required actuation (control problem).
Progress and development
Digestion of food is a regular activity in many species to maintain nourishment and growth. In humans, digestion depends on the process of a churning action to break down the food in a stomach. Medical and biomedical experts stated that this physical motility frequency and deformation significantly affect the digestion process. Antral contraction wave (ACW) is the mechanical peristalsis action occurs in the smooth muscles of a stomach. Researchers from diverse disciplines are seeking more understanding of the ACW mechanism.
The current state of physical stomach replicates is usually rigid models. The motility of these robots is different compared to the observed biological organ. In response to this gap, we have started developing a soft-bodied robot to mimic the ACW physical deformation similar to the gastric motility. It is assumed that the biologically-inspired robot will facilitate the investigation of ACW by physical peristaltic actuation model. The conceptualization and specification of the soft gastric actuator have been developed. The primary robot conduit has been designed with geometry similar to that in the biological gastric. The proposed soft actuation method was tested by finite element analysis (FEA) preceding the final conceptual gastric-soft robot design. A prototype three-layered ring-shaped soft actuator has been designed, simulated, fabricated and tested.