Redesigning a flexural joint for metal-based additive manufacturing

Traditional rigid mechanisms exhibit problems such as assembly difficulties, friction and lubrification. Flexure-based compliant mechanisms, instead, are monolithic and gain their mobility thanks to proper design and materialdeflection. Designing and producing a compliant mechanism accurately and conveniently iscrucial. Thanks to its capabilities, additive manufacturing (AM) approach can provide optimal design and production and open the way to new, unexploited performances. This study investigates the redesign of a traditional cantilevered pivot. The redesign considers the performance improvements by exploiting the advantages of the AM based on laser powder bed fusion (L-PBF). The maximum tensileand compressive loads of the redesigned joint were identified. The structure was optimised by considering the most critical geometricalparameters in terms of mechanical performance. The geometricalfactorscomply with the design rules for L-PBF process, to maximise the dimensional and surface accuracies.The new approach to the flexural joint design presented in this paper provided higher mobility if compared with the traditional approach. Therefore, this study makes a major contribution to research on the production of precision alignment mechanisms and scientific instruments

3D printed flexure hinges for soft monolithic prosthetic fingers

Mechanical compliance is one of the primary properties of structures in nature playing a key role in their efficiency. This study investigates a number of commonly used flexure hinges to determine a flexure hinge morphology, which generates large displacements under a lowest possible force input. The aim of this is to design a soft and monolithic robotic finger. Fused deposition modeling, a low-cost 3D printing technique, was used to fabricate the flexure hinges and the soft monolithic robotic fingers. Experimental and finite element analyses suggest that a nonsymmetric elliptical flexure hinge is the most suitable type for use in the soft monolithic robotic finger. Having estimated the effective elastic modulus, flexion of the soft monolithic robotic fingers was simulated and this showed a good correlation with the actual experimental results. The soft monolithic robotic fingers can be employed to handle objects with unknown shapes and are also potential low-cost candidates for establishing soft and one-piece prosthetic hands with light weight. A three-finger gripper has been constructed using the identified flexure hinge to handle objects with irregular shapes such as agricultural products

Three-Dimensional Kinematic Modeling of Helix-Forming Lamina-Emergent Soft Smart Actuators Based on Electroactive Polymers

Robotic systems consisting of rigid elements connected to each other with single degree of freedom joints have been studied extensively. Robotic systems made of soft and smart materials are expected to provide a high dexterity and adaptability to their physical environment, like their biological counterparts. Electroactive polymer (EAP) actuators, also known as artificial muscles, which can operate both in wet and in dry environments with their promising features such as a low foot-print in activation and energy consumption, suitability to miniaturization, noiseless, and fully compliant operation can be employed to articulate a soft robotic system. This paper reports on kinematic modeling of a polypyrrolebased EAP actuator which is designed and fabricated to form helical configurations in 3-D from its initially spiral 2-D configuration. Denavit-Hartenberg transformations are combined with the backbone model of the actuator to establish the kinematic model. A parametric model has then been incorporated into the kinematic model to accurately estimate the helical configurations of the EAP actuator as a function of time under an electrical input. Experimental and simulation results, which are in good correlation, suggest that the proposed modeling approach is effective enough to estimate the 3-D helical configurations of the EAP actuator

Faculty Publications and Creative Works 1999

One of the ways in which we recognize our faculty at the University of New Mexico is through Faculty Publications & Creative Works. An annual publication, it highlights our faculty\u27s scholarly and creative activities and achievements and serves as a compendium of UNM faculty efforts during the 1999 calendar year. Faculty Publications & Creative Works strives to illustrate the depth and breadth of research activities performed throughout our University\u27s laboratories, studios and classrooms. We believe that the communication of individual research is a significant method of sharing concepts and thoughts and ultimately inspiring the birth of new ideas. In support of this, UNM faculty during 1999 produced over 2,292 works, including 1,837 scholarly papers and articles, 78 books, 82 book chapters, 175 reviews, 113 creative works and 7 patented works. We are proud of the accomplishments of our faculty which are in part reflected in this book, which illustrates the diversity of intellectual pursuits in support of research and education at the University of New Mexico

MC 2019 Berlin Microscopy Conference - Abstracts

Das Dokument enthält die Kurzfassungen der Beiträge aller Teilnehmer an der Mikroskopiekonferenz "MC 2019", die vom 01. bis 05.09.2019, in Berlin stattfand