scholarly journals Feasibility of Fiber Reinforcement Within Magnetically Actuated Soft Continuum Robots

2021 ◽  
Vol 8 ◽  
Author(s):  
Peter Lloyd ◽  
Zaneta Koszowska ◽  
Michele Di Lecce ◽  
Onaizah Onaizah ◽  
James H. Chandler ◽  
...  
Keyword(s):  
Design Space ◽  
Magnetization Vector ◽  
Fiber Reinforcement ◽  
Magnetic Torque ◽  
Local Magnetization ◽  
Continuum Robots ◽  
Flexible Materials ◽  
Magnetically Actuated ◽  
Wide Range ◽  
Continuum Manipulators

Soft continuum manipulators have the potential to replace traditional surgical catheters; offering greater dexterity with access to previously unfeasible locations for a wide range of interventions including neurological and cardiovascular. Magnetically actuated catheters are of particular interest due to their potential for miniaturization and remote control. Challenges around the operation of these catheters exist however, and one of these occurs when the angle between the actuating field and the local magnetization vector of the catheter exceeds 90°. In this arrangement, deformation generated by the resultant magnetic moment acts to increase magnetic torque, leading to potential instability. This phenomenon can cause unpredictable responses to actuation, particularly for soft, flexible materials. When coupled with the inherent challenges of sensing and localization inside living tissue, this behavior represents a barrier to progress. In this feasibility study we propose and investigate the use of helical fiber reinforcement within magnetically actuated soft continuum manipulators. Using numerical simulation to explore the design space, we optimize fiber parameters to enhance the ratio of torsional to bending stiffness. Through bespoke fabrication of an optimized helix design we validate a single, prototypical two-segment, 40 mm × 6 mm continuum manipulator demonstrating a reduction of 67% in unwanted twisting under actuation.

scholarly journals A Wire-Driven Discrete Continuum Robot Sliding and Non-sliding Backbone Design Analysis and Validation of Kinematics/Kinetics

2020 ◽  
Author(s):  
Azamat Yeshmukhametov ◽  
Zholdas Buribayev ◽  
Beibut Amirgaliyev ◽  
Yedilkkhan Amirgaliyev
Keyword(s):  
Bending Test ◽  
Robot Kinematics ◽  
Robot Arm ◽  
Continuum Robots ◽  
Sliding Mechanism ◽  
Wide Range ◽  
Payload Capacity ◽  
Continuum Robot ◽  
Continuum Manipulators ◽  
And Control

Wire-driven hyper-redundant continuum manipulators are gaining more popularity and finding more applications in industry and in minimally invasive surgery. Unlike traditional rigid link manipulators, continuum robots with a flexible backbone structure are able to work in a highly constrained workspace and in an unstructured environment. However, in spite of a possible wide range of reachability, continuum manipulators have some issues related to payload capacity, accuracy and control. Therefore, in this research, we propose a novel hyper-redundant continuum robot with a passive sliding disc mechanism to improve payload capacity and accuracy. To prove the sliding mechanism concept, we demonstrate a comparison analysis with a conventional non-sliding continuum robot arm in a payload test, a bending test and a reachability test. Moreover, with this novel design, we are proposing robot kinematics and kinetic formulation and simulation results to validate the effectiveness of the sliding disc mechanism.

A novel design space concept for design of concrete foundation supporting chemical reactors

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Osama Bedair
Keyword(s):  
Design Space ◽  
Cost Savings ◽  
Space Representation ◽  
Chemical Reactors ◽  
Content Type ◽  
Gas Recovery ◽  
Wide Range ◽  
Numerical Finite Element ◽  
Novel Concept ◽  
Reactor Models

PurposeThis paper presents a novel concept for design of concrete support system for chemical reactors used in refineries and petrochemical plants. Graphical method is described that can be used to size the concrete base and piling system. Recommendations are also provided to optimize the parameters required for the design. The procedure is illustrated for design of two reactor models commonly used in gas recovery units.Design/methodology/approachDesign space representation for the foundation system is described for chemical reactors with variable heights. The key points of the design graph are extracted from the numerical finite element models. The reactor load is idealized at discrete points to transfer the loads to the piles. Bilateral spring system is used to model the soil restrains.FindingsThe graphical approach is economical and provides the design engineer the flexibility to select the foundation parameters from wide range of options.Practical implicationsThe concept presented in the paper can be utilized by engineers in the industry for design of chemical reactors. It must be noted that little guidelines are currently available in practice addressing the structural design aspects.Originality/valueA novel concept is presented in this paper based on significant industrial design experience of reactor supports. Using the described method leads to significant cost savings in material quantity and engineering time.

The Design Space of Superalloy-Based Actively Cooled Combustor Walls for H2-Powered Hypersonic Vehicles

2007 ◽  
Author(s):  
Lorenzo Valdevit ◽  
Natasha Vermaak ◽  
Frank W. Zok ◽  
A. G. Evans
Keyword(s):  
Design Space ◽  
Ceramic Matrix Composites ◽  
Nickel Superalloy ◽  
Hypersonic Vehicles ◽  
Matrix Composites ◽  
Niobium Alloys ◽  
Design Constraint ◽  
Mechanical Loads ◽  
Nickel Copper ◽  
Wide Range

The walls of combustion chambers used for air-breathing hypersonic vehicles are subject to substantial thermo-mechanical loads, and require active cooling by the fuel in conjunction with advanced material systems. Solutions based on metallics are preferable to ceramic matrix composites due to their lower cost and greater structural robustness. Previous work suggested that a number of metallic materials (e.g. Nickel, Copper and Niobium alloys) could be used to fabricate actively cooled sandwich structures that withstand the thermo-mechanical loads for a Mach 7, hydrocarbon-powered vehicle (albeit with different weight efficiencies). However, this conclusion changes when the Mach number is increased. This work explores the feasibility of the Nickel superalloy MARM246 for a wide range of Mach numbers (7–12). Since hydrocarbon fuels are limited to Mach 7–8, Hydrogen is used as the coolant of choice. A previously derived analytical model (appropriately modified for gaseous coolant) is used to explore the design space. The relative importance of each design constraint is assessed, resulting in the distillation of essential guidelines for optimal design.

Numerical Method for Studying Bearing Gap Pressure Wave Development and Subsequent Performance Mapping of Externally Pressurized Gas Journal Bearings

2019 ◽  
Author(s):  
Tom M. Lawrence ◽  
Marvin D. Kemple
Keyword(s):  
Numerical Method ◽  
Cross Section ◽  
Mass Flow ◽  
Pressure Wave ◽  
Design Space ◽  
Numerical Study ◽  
Pressure Waves ◽  
Wide Range ◽  
Wave Development ◽  
Static Instability

Abstract In previous work, numerical methods were developed to determine the pressure waves (pressure distribution) in the bearing gap of round externally pressurized gas bearings (EPB’s) that were pressurized through porous liners (PL bearings) or through liners with rows of feedholes (FH bearings). When integrated and differentiated these pressure portraits yield the net hydrodynamic force (FH) between the shaft and the bushing and the mass flow rates through the bearing gap. These results successfully replicated force-deflection curves and mass flow rate data for experimentally tested prototype FH and PL bearings over a wide range of mass flow constriction and clearances. Subsequently the numerical study was expanded to a broader design space of clearance and mass flow compensation. Also, a bearing performance mapping method of mapping the normalized bearing load over the clearance-eccentric deflection plane was developed for different levels of mass compensation. These performance maps produced a very interesting result as they indicated certain areas in the design space of FH bearings where static instability (negative stiffness) would be encountered. This static instability was not observed in the experimental data but is noted in references as known to occur in practice. Because this numerical method is based on the development of pressure wave portraits, the FH pressure wave could then be “dissected” in the areas of the onset of static instability which gave much insight as to the possible causes of static instability. This initial work, then, was perhaps the first to predict where in design space static instability would occur and yield some insight via examination of the corresponding pressure waves as to the cause. The numeric techniques developed, however are in no way limited to non-rotating bearings but are extensible to rotating bearings. The method is also easily extensible to examination of any configuration of feedholes or orifices. Nor is it limited to parallel deflections but can yield results for unbalanced loads. The method is also not limited to round bearings but can be applied to any cross-section configuration of bearing gap cross section such as a 3 lobed bearing or a slotted 3 lobed bearing. Examination of the resulting pressure wave development patterns for different scenarios can be examined to garner insight as to the causes of differing performance that can be applied to alterations towards optimization. Thus sharing in detail the developed numerical method underlying these studies seems worthwhile.

A Machine Learning-Based Design Representation Method for Designing Heterogeneous Microstructures

2015 ◽  
Vol 137 (5) ◽  
Author(s):  
Hongyi Xu ◽  
Ruoqian Liu ◽  
Alok Choudhary ◽  
Wei Chen
Keyword(s):  
Machine Learning ◽  
Design Space ◽  
Structure Property ◽  
Microstructure Design ◽  
Significant Information ◽  
Design Variables ◽  
Wide Range ◽  
Small Set ◽  
Microstructural Design ◽  
Heterogeneous Microstructures

In designing microstructural materials systems, one of the key research questions is how to represent the microstructural design space quantitatively using a descriptor set that is sufficient yet small enough to be tractable. Existing approaches describe complex microstructures either using a small set of descriptors that lack sufficient level of details, or using generic high order microstructure functions of infinite dimensionality without explicit physical meanings. We propose a new machine learning-based method for identifying the key microstructure descriptors from vast candidates as potential microstructural design variables. With a large number of candidate microstructure descriptors collected from literature covering a wide range of microstructural material systems, a four-step machine learning-based method is developed to eliminate redundant microstructure descriptors via image analyses, to identify key microstructure descriptors based on structure–property data, and to determine the microstructure design variables. The training criteria of the supervised learning process include both microstructure correlation functions and material properties. The proposed methodology effectively reduces the infinite dimension of the microstructure design space to a small set of descriptors without a significant information loss. The benefits are demonstrated by an example of polymer nanocomposites optimization. We compare designs using key microstructure descriptors versus using empirically chosen microstructure descriptors as a demonstration of the proposed method.

Integration of Electrografted Layers for the Metallization of Deep TSVs

2010 ◽  
Vol 7 (3) ◽  
pp. 119-124
Author(s):  
F. Raynal ◽  
V. Mevellec ◽  
N. Frederich ◽  
D. Suhr ◽  
I. Bispo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Shelf Life ◽  
Design Space ◽  
Complete Characterization ◽  
Monitoring Strategy ◽  
Ic Design ◽  
Preliminary Results ◽  
Wide Range ◽  
Readiness Level

This paper describes production-readiness level of electrografted (eG) and chemical grafted (cG) layers deposited on a wide range of through silicon via (TSV) dimensions. Three layers are required to achieve via metallization: eG insulator, cG barrier, and eG copper seed. Complete characterization of each layer of the stack has been achieved, including electrical and mechanical properties. Impact on the 3D-IC design space of the electrografting nanotechnology optimized for highly conformal growth of TSV films is discussed. Four chemical baths are required to achieve the deposition of the three layers, shelf life, and bath monitoring strategy of each chemistry being presented in the last part of the paper. Some preliminary results of copper plating directly on top of the cG barrier are also reported.

scholarly journals The Impact of a Paraelectric layer in the FE/DE Stack on Performance of NCFET

2022 ◽  
Author(s):  
Harshit Kansal ◽  
Aditya S Medury
Keyword(s):  
Low Power ◽  
Layer Thickness ◽  
Remnant Polarization ◽  
Design Space ◽  
Performance Parameters ◽  
Analog Performance ◽  
Wide Range ◽  
The Impact ◽  
Tcad Simulations ◽  
Mfis Structure

<div>In this letter, through TCAD simulations, we show that the introduction of a thin paraelectric (PE) layer between the ferroelectric (FE) and dielectric (DE) layers in an MFIS structure, expands the design space for the FE layer enabling hysteresis-free and steep subthreshold behavior, even with a thicker FE layer. This can be explained by analyzing the FE-PE stack from a capacitance perspective where the thickness of the PE layer in the FE-PE stack has the effect of reducing the FE layer thickness, while also reducing the remnant polarization. Finally, for the same FE-PE-DE stack, analog performance parameters such as $\frac{g_{m}} g_{ds}}$ and $\frac{g_{m}}{I_{d}}$ are analyzed, showing good characteristics over a wide range of gate lengths, at low drain voltages, thus demonstrating applicability for low power applications.</div>

scholarly journals Implementation of integrated design space exploration of scheduling, allocation and binding in high level synthesis using multi structure genetic algorithm

2021 ◽  
Author(s):  
Michael Gebremariam
Keyword(s):  
Genetic Algorithm ◽  
Design Space Exploration ◽  
Design Space ◽  
Space Exploration ◽  
Integrated Design ◽  
High Level Synthesis ◽  
C Language ◽  
Low Level ◽  
Wide Range ◽  
High Level

The objective of this project is to develop a software tool which assists in comparison of a work known as "M-GenESys: Multi Structure Genetic Algorithm based Design Space Exploration System for Integrated Scheduling, Allocation and Binding in High Level Synthesis" with another well established GA approach known as "A Generic Algorithm for the Design Space Exploration of Data paths During High-Level Synthesis". Two sets of software are developed based on both approaches using Microsoft Visual 2005 C# language. The C# language is an object-oriented language that is aimed at enabling programmers to quickly develop a wide range of applications on the Microsoft .NET platform. The goal of C# and the .NET platform is to shorten development time by freeing the developer from worrying about several low level plumbing issues such as memory equipment, type safety issues, building low level libraries, array bound checking, etc., thus allowing developers to actually spend their time and energy working on the application and business logic.

scholarly journals Parametric Shape and Manufacturing Optimization of Customized Kitesurf Hydrofoils

Proceedings ◽  
2020 ◽  
Vol 49 (1) ◽  
pp. 126
Author(s):  
Jakob Schmidt ◽  
Marc Fleischmann ◽  
Conrad Ehemann ◽  
Jörg Kaufmann ◽  
Holger Cebulla
Keyword(s):  
Design Space ◽  
Fluid Dynamic ◽  
Manufacturing Processes ◽  
Mold Surface ◽  
Cfd Analysis ◽  
Element Analysis ◽  
Reinforcement Structure ◽  
Manufacturing Optimization ◽  
Wide Range ◽  
Finite Elements Model

To minimize the costs of the current manufacturing of kitesurf hydrofoil wings, a workflow using a finite elements model was developed. By coupling a computational fluid dynamic (CFD) analysis with a structural finite element analysis (FEA), an optimization based on a genetic algorithm is implemented. The design space of the optimization is defined by the manufacturing processes. This enables the algorithm to find wing shapes which are not only suitable for the rider’s weight and preferred take-off speed but can also be produced directly on a universal mold surface. To reduce the amount of cut-off material and sustain the mechanical stresses, the output of the optimization contains the required number and orientation of all fiber layers within the reinforcement structure. This research shows that a single mold can produce different wing shapes to satisfy the needs of a wide range of customers.

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