Additive manufacturing (AM) is one of the emerging production methodologies transforming the industrial landscape. However, application of the technology in fluidic power transmission and actuation is still limited. AM pneumatic stepper motors have been previously introduced to the field of image-guided surgical robotics, where their disposability and customizability are considered a significant advantage over conventional manufacturing. However, intrinsic dimensional limitations of AM parts and their poor surface quality affect mechanical performance. In this letter, a novel design, PneuAct-II, is presented combining AM, subtractive machining, and off-the-shelf components to achieve higher mechanical performance and resolution. Moreover, a motor identification setup has been built to automatically measure different aspects of the PneuAct motors, including wear, friction, leakage, and stall behavior at various boundary conditions. The effects of input pressure, stepping frequency, signal-width, and external torque on the stall behavior of motors with different clearances are studied. A maximum torque of 0.39 N•m at an input pressure of 6.5 bar is achieved for a motor with a total volume of 90 cm 3 , and a clearance of 156 µm. A nominal resolution of 2.25 • at full-pitch and 1.125 • at half-pitch is accomplished. Both resolution and mechanical performance (667 N•m/bar • m 3 ) outperform the state-of-the-art (240 N•m/bar • m 3 by PneuAct-I).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.