scholarly journals Design of a Simple and Modular 2-DOF Ankle Physiotherapy Device Relying on a Hybrid Serial-Parallel Robotic Architecture

2011 ◽  
Vol 8 (1) ◽  
pp. 101-114 ◽  
Author(s):  
Christos E. Syrseloudis ◽  
Ioannis Z. Emiris ◽  
Theodore Lilas ◽  
Artemis Maglara
Keyword(s):  
Parametric Design ◽  
Low Cost ◽  
Parallel Robots ◽  
Hybrid Architecture ◽  
Foot Kinematics ◽  
Human Foot ◽  
Large Size ◽  
Ankle Rehabilitation ◽  
Robotic Architecture ◽  
Velocity Transmission

The aim of this work is to propose a new 2-DOF robotic platform with hybrid parallel-serial structure and to undertake its parametric design so that it can follow the whole range of ankle related foot movements. This robot can serve as a human ankle rehabilitation device. The existing ankle rehabilitation devices present typically one or more of the following shortcomings: redundancy, large size, or high cost, hence the need for a device that could offer simplicity, modularity, and low cost of construction and maintenance. In addition, our targeted device must be safe during operation, disallow undesirable movements of the foot, while adaptable to any human foot. Our detailed study of foot kinematics has led us to a new hybrid architecture, which strikes a balance among all aforementioned goals. It consists of a passive serial kinematics chain with two adjustable screws so that the axes of the chain match the two main ankle-axes of typical feet. An active parallel chain, which consists of two prismatic actuators, provides the movement of the platform. Thus, the platform can follow the foot movements, thanks to the passive chain, and also possesses the advantages of parallel robots, including rigidity, high stiffness and force capabilities. The lack of redundancy yields a simpler device with lower size and cost. The paper describes the kinematics modelling of the platform and analyses the force and velocity transmission. The parametric design of the platform is carried out; our simulations confirm the platform's suitability for ankle rehabilitation.

Sensible use of observational clinical data

2011 ◽  
Vol 22 (1) ◽  
pp. 7-13 ◽  
Author(s):  
J Marc Overhage ◽  
Lauren M Overhage
Keyword(s):  
Health Care ◽  
Clinical Trials ◽  
Medical Research ◽  
Observational Data ◽  
Clinical Data ◽  
Low Cost ◽  
Clinical Care ◽  
Data Sets ◽  
Large Size ◽  
Health Care Operations

Observational data sets offer many potential advantages for medical research including their low cost, large size and generalisability. Because they are collected for clinical care and health care operations purposes, observational data sets have some limitations that must be considered in order to perform useful analyses. Sensible use of observational data sets can yield valuable insights, particularly when clinical trials are impractical.

Solder Joint Reliability Study for Wafer Level Packages on Flexible and Rigid Boards

2013 ◽  
Vol 2013 (1) ◽  
pp. 000039-000044
Author(s):  
Gary Gu ◽  
Jon Chadwick ◽  
Daniel Jin
Keyword(s):  
Solder Joint ◽  
Parametric Design ◽  
Low Cost ◽  
Wafer Level ◽  
Solder Joint Reliability ◽  
Conformal Coating ◽  
Joint Reliability ◽  
Chip Size ◽  
The Right ◽  
Elastic Plastic Materials

Applications of Wafer Level Packages (WLPs) have shown tremendous growth in the rapid developing smartphones and other portable electronic devices. The technology trends lead to smaller chip size, low cost, and more integrated functions, but also face higher reliability requirements due to the reduced number of solder bumps as well as smaller bump size and height. New assembly technologies such as flexible phone board and conformal coating also brought up new thermo-mechanical reliability challenges. Based on 3D finite element modeling, the current studies focus on solder joint reliability of WLPs and compared between flex based and traditional rigid based WLP assemblies. Conformal coated and underfilled WLPs as well as some bump parameters are also studied. The parametric studies were carried out in ANSYS and all models were created by using APDL (ANSYS Parametric Design Language) scripts. Each simulation starts from stress free status set at solder reflow temperature and were subjected to thermal cyclic load between −40 and +125°C with ramp and dwell time. Creep strain was considered for solder alloys and kinematic plastic hardening was considered for other elastic-plastic materials. The solder fatigue life is estimated by using modified Coffin-Manson equation and was compared with available thermal cycling test data. The results show that underfill is still the most effective option and conformal coating can play an important role if the right material is selected. Bump parameters such as height, which have certain effects on the solder reliability on WLP-on-Rigid, have limited impact on WLP-on-Flex assembly.

A New Flexible Track Automatic Drilling System

2013 ◽  
Vol 433-435 ◽  
pp. 2178-2183 ◽  
Author(s):  
Yun Bo Bi ◽  
Yi Hang Jiang ◽  
Yong Chao Li ◽  
Wei Wang ◽  
Mian Gao ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
System Structure ◽  
Aircraft Assembly ◽  
Large Size ◽  
Flexible Track ◽  
Transformation Algorithm ◽  
Drilling System ◽  
High Computational Efficiency

The Flexible track automatic drilling equipment is widely used in aircraft assembly because of the low cost, high efficiency and high quality of holes. This paper constructs a new flexible track drilling system for large-size aircraft assembly. The system structure is introduced, and the transformation algorithm between product/device coordinate system and axes position parameters is proposed. The experimental results show that the transformation algorithm has the merits of high computational efficiency and high stability, and can meet the requirement of precision drilling.

scholarly journals Effectiveness of selective area growth using van der Waals h-BN layer for crack-free transfer of large-size III-N devices onto arbitrary substrates

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Soufiane Karrakchou ◽  
Suresh Sundaram ◽  
Taha Ayari ◽  
Adama Mballo ◽  
Phuong Vuong ◽  
...  
Keyword(s):  
Low Cost ◽  
Van Der Waals ◽  
Thermal Dissipation ◽  
Silicon Substrates ◽  
Device Performance ◽  
Selective Area Growth ◽  
Material Quality ◽  
Large Size ◽  
Selective Area ◽  
Area Growth

AbstractSelective Area van der Waals Epitaxy (SAVWE) of III-Nitride device has been proposed recently by our group as an enabling solution for h-BN-based device transfer. By using a patterned dielectric mask with openings slightly larger than device sizes, pick-and-place of discrete LEDs onto flexible substrates was achieved. A more detailed study is needed to understand the effect of this selective area growth on material quality, device performance and device transfer. Here we present a study performed on two types of LEDs (those grown on h-BN on patterned and unpatterned sapphire) from the epitaxial growth to device performance and thermal dissipation measurements before and after transfer. Millimeter-size LEDs were transferred to aluminum tape and to silicon substrates by van der Waals liquid capillary bonding. It is shown that patterned samples lead to a better material quality as well as improved electrical and optical device performances. In addition, patterned structures allowed for a much better transfer yield to silicon substrates than unpatterned structures. We demonstrate that SAVWE, combined with either transfer processes to soft or rigid substrates, offers an efficient, robust and low-cost heterogenous integration capability of large-size devices to silicon for photonic and electronic applications.

Performance and Design Comparison of a Bulk Thermoelectric Cooler With a Hybrid Architecture

2016 ◽  
Vol 8 (2) ◽  
Author(s):  
Margaret Antonik ◽  
Brendan T. O'Connor ◽  
Scott Ferguson
Keyword(s):  
Low Cost ◽  
Electrical Current ◽  
Performance Outcomes ◽  
Polymer Materials ◽  
Plastic Substrate ◽  
Thermoelectric Device ◽  
Hybrid Architecture ◽  
Cost Information ◽  
Thermoelectric Coolers ◽  
Design Variables

This paper compares the economic viability and performance outcomes of two different thermoelectric device architectures to determine the advantages and appropriate use of each configuration. Hybrid thermoelectric coolers (TECs) employ thin-film thermoelectric materials sandwiched between a plastic substrate and form a corrugated structure. Roll-to-roll (R2R) manufacturing and low-cost polymer materials offer a cost advantage to the hybrid architecture at the sacrifice of performance capabilities while conventional bulk devices offer increased performance at a higher cost. Performance characteristics and cost information are developed for both hybrid and conventional bulk single-stage thermoelectric modules. The design variables include device geometry, electrical current input, and thermoelectric material type. The tradeoffs between cooling performance and cost will be explored, and the thermoelectric system configuration is analyzed for both hybrid and conventional bulk TECs.

scholarly journals Single-Seed Casting Large-Size Monocrystalline Silicon for High-Efficiency and Low-Cost Solar Cells

Engineering ◽  
2015 ◽  
Vol 1 (3) ◽  
pp. 378-383 ◽  
Author(s):  
Bing Gao ◽  
Satoshi Nakano ◽  
Hirofumi Harada ◽  
Yoshiji Miyamura ◽  
Takashi Sekiguchi ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Efficiency ◽  
Low Cost ◽  
Monocrystalline Silicon ◽  
Single Seed ◽  
Large Size

Preparation of large-size Y123 films on CeO2-buffered sapphire substrates by MOD using a low-cost vacuum technique

2007 ◽  
Vol 463-465 ◽  
pp. 549-553 ◽  
Author(s):  
I. Yamaguchi ◽  
M. Sohma ◽  
K. Tsukada ◽  
W. Kondo ◽  
K. Kamiya ◽  
...  
Keyword(s):  
Low Cost ◽  
Sapphire Substrates ◽  
Large Size

An Innovative Indoor Coordinate Measuring System for Large-Scale Metrology Based on a Distributed IR Sensor Network

2009 ◽  
Author(s):  
Maurizio Galetto ◽  
Luca Mastrogiacomo ◽  
Barbara Pralio
Keyword(s):  
Distributed System ◽  
Large Scale ◽  
Low Cost ◽  
Measuring System ◽  
Distributed Network ◽  
Network Configuration ◽  
Large Size ◽  
Sensor Devices ◽  
Coordinate Measurements ◽  
System Prototype

The aim of this paper is to describe the architecture and the working principles of a novel InfraRed (IR) optical-based distributed system, designed to perform low-cost indoor coordinate measurements of large-size objects. The hardware/software architecture and system functionalities are discussed, focusing the attention on the integration of methods for distributed network configuration, sensors self-calibration, 3D point localization, and data processing. A preliminary performance evaluation of the sensor devices as well as of the overall measuring system is carried out by discussing the experimental results obtained with a system prototype.

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