The use of origami in engineering has significantly expanded in recent years, spanning deployable structures across scales, folding robotics and mechanical metamaterials. However, finding foldable paths can be a formidable task as the kinematics are determined by a nonlinear system of equations, often with several degrees of freedom. In this article, we leverage a Lagrangian approach to derive reduced-order compatibility conditions for rigid-facet origami vertices with reflection and rotational symmetries. Then, using the reduced-order conditions, we derive exact, multi-degree of freedom solutions for degree 6 and degree 8 vertices with prescribed symmetries. The exact kinematic solutions allow us to efficiently investigate the topology of allowable kinematics, including the consideration of a self-contact constraint, and then visually interpret the role of geometric design parameters on these admissible fold paths by monitoring the change in the kinematic topology. We then introduce a procedure to construct lower-symmetry kinematic solutions by breaking symmetry of higher-order kinematic solutions in a systematic way that preserves compatibility. The multi-degree of freedom solutions discovered here should assist with building intuition of the kinematic feasibility of higher-degree origami vertices and also facilitate the development of new algorithmic procedures for origami-engineering design.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.
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http://dx.doi.org/10.1098/rsta.2024.0203 | DOI Listing |
Comput Biol Med
January 2025
UCL Mechanical Engineering, University College London, UK; Ri.MED Foundation, Palermo, Italy; University of Palermo, Department of Engineering, Palermo, Italy. Electronic address:
Aortic valve replacements, both surgical and transcatheter, are nowadays widely employed treatments. Although clinically effective, these procedures are correlated with potentially severe clinical complications which can be associated with the non-physiological haemodynamics that they establish. In this work, the fluid dynamics changes produced by surgical and transcatheter aortic valve replacements are analysed and compared with an ideal healthy native valve configuration, employing advanced fluid-structure interaction (FSI) simulations.
View Article and Find Full Text PDFAccid Anal Prev
January 2025
Department of Computer Engineering, Hongik University, Seoul, 04066, Republic of Korea. Electronic address:
Automated Vehicles (AVs) are on the cusp of commercialization, prompting global governments to organize the forthcoming mobility phase. However, the advancement of technology alone cannot guarantee the successful commercialization of AVs without insights into the accidents on the read roads where Human-driven Vehicles (HV) coexist. To address such an issue, The New Car Assessment Program (NCAP) is currently in progress, and scenario-based approaches have been spotlighted.
View Article and Find Full Text PDFSoft Matter
January 2025
School of Medicine and Health, Harbin Institute of Technology, XiDaZhi Street 92, Harbin, 150001, China.
Enzyme-powered synthetic colloidal motors hold promising potential for medical applications because of their unique features such as self-propulsion, sub-micrometer size, fuel bioavailability, and structural and functional versatility. However, the key parameters influencing the propulsion efficiency of enzyme-powered colloidal motors still remain unclear. Here, we report the effect of the neck length of urease-powered pentosan flask-like colloidal motors on their kinematic behavior resembling the role of bacterial flagella.
View Article and Find Full Text PDFSci Rep
January 2025
Commercial Product R&D Institute, Dongfeng Automobile Co., Ltd., Wuhan, 430070, People's Republic of China.
The rapid acceleration of urbanization and the surge in car ownership necessitate efficient automatic parking solutions in constricted spaces to address the escalating urban parking issue. To optimize space utilization, enhance traffic efficiency, and mitigate accident risks, a method is proposed for smooth, comfortable, and adaptable automatic parking trajectory planning. This study initially employs a hybrid A* algorithm to generate a preliminary path, then fits the velocity and acceleration based on a cubic polynomial.
View Article and Find Full Text PDFJMIR Hum Factors
January 2025
Department of Biomedical Engineering, Chung Yuan Christian University, No. 200, Zhongbei Road, Zhongli District, Toayuan City, 32023, Taiwan, 886 32564507.
Background: Muscle fatigue, characterized by reduced force generation during repetitive contractions, impacts older adults doing daily activities and athletes during sports activities. While various sensors detect muscle fatigue via muscle activity, biochemical markers, and kinematic parameters, a real-time wearable solution with high usability remains limited. Plantar pressure monitoring detects muscle fatigue through foot loading changes, seamlessly integrating into footwear to improve the usability and compliance for home-based monitoring.
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