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Despite an emerging interest in soft and rigid pneumatic lightweight robots, the pneumatic rotary actuators available to date either are unsuitable for servo pneumatic applications or provide a limited angular range. This study describes the functional principle, design, and manufacturing of a servo pneumatic rotary actuator that is suitable for continuous rotary motion and positioning. It contains nine radially arranged linear bellows actuators with rollers that push forward a cam profile. Proportional valves and a rotary encoder are used to control the bellows pressures in relation to the rotation angle. Introducing freely programmable servo pneumatic commutation increases versatility and allows the number of mechanical components to be reduced in comparison to state-of-the-art designs. The actuator presented is designed to be manufacturable using a combination of standard components, selective laser sintering, elastomer molding with novel multi-part cores and basic tools. Having a diameter of 110 mm and a width of 41 mm, our prototype weighs less than 500 g, produces a torque of 0.53 Nm at 1 bar pressure and a static positioning accuracy of 0.31° with no limit of angular motion. By providing a description of design, basic kinematic equations, manufacturing techniques, and a proof of concept, we enable the reader to envision and explore future applications. [ABSTRACT FROM AUTHOR]

Transportation infrastructure relies heavily on asphalt pavement, but conventional bitumen-based mixtures present several drawbacks. This study assesses the potential of poly(methyl methacrylate) resins and thixotropic fillers as substitutes for bitumen to improve pavement performance. The research concentrates on enhancing current formulations that incorporate a thermosetting polymer and mineral (stiffening) fillers, with the objective of increasing durability, extending the product life cycle, and optimizing raw material usage. Utilizing dynamic thermomechanical analyses, the viscoelastic characteristics of resins are examined, with a focus on their mechanical properties' dependence on load frequency and temperature. The investigation also evaluates the impact of different fillers, including silica sand, silica dust, and basalt sand, on viscoelastic behavior and load-bearing capacity, offering valuable insights into the relationships between material structure and properties. The findings reveal that stiffness is predominantly affected by the quantity of silica dust, whereas the force plateau depends on the amount of sand. This study contributes crucial information for the development of more sustainable and robust pavement materials for future applications. [ABSTRACT FROM AUTHOR]

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A foreword to the journal "Frontiers of Literary Studies in China" is presented.

An introduction is presented to a series of articles on Chinese scholar Shao Yong arising from the January 2012 Workshop in Celebration of the 1000th Anniversary of the Birth of Shao Yong (January 21, 1012 - July 27, 1077), held at Friedrich-Alexander-Universität in Erlangen-Nürnberg, Germany.

State-of-the-art Additive Manufacturing processes such as three-dimensional (3D) inkjet printing are capable of producing geometrically complex multi-material components with integrated elastomeric features. Researchers and engineers seeking to exploit these capabilities must handle the complex mechanical behavior of inkjet-printed elastomers and expect a lack of suitable design examples. We address these obstacles using a pneumatic actuator as an application case. First, an inkjet-printable actuator design with elastomeric bellows structures is presented. While soft robotics research has brought forward several examples of inkjet-printed linear and bending bellows actuators, the rotary actuator described here advances into the still unexplored field of additively manufactured pneumatic lightweight robots with articulated joints. Second, we demonstrate that the complex structural behavior of the actuator's elastomeric bellows structure can be predicted by Finite Element (FE) simulation. To this end, a suitable hyperviscoelastic material model was calibrated and compared to recently published models in a multiaxial-state-of-stress relaxation experiment. To verify the material model, Finite Element simulations of the actuator's deformation behavior were conducted, and the results compared to those of corresponding experiments. The simulations presented here advance the materials science of inkjet-printed elastomers by demonstrating use of a hyperviscoelastic material model for estimating the deformation behavior of a prototypic robotic component. The results obtained contribute to the long-term goal of additively manufactured and pneumatically actuated lightweight robots., Competing Interests: GD, SL and RN were employed by the company Festo SE and Co. KG. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Dämmer, Lackner, Laicher, Neumann and Major.)