scholarly journals Design Tradeoffs in the Development of a Wearable Soft Exoskeleton for Upper Limb Mobility Disorders

2019 ◽  
Author(s):  
Esther Foo ◽  
Heidi Woelfle ◽  
Brad Holschuh
Keyword(s):  
Shape Memory Alloy ◽  
Power Input ◽  
The Body ◽  
Crucial Point ◽  
Mobility Support ◽  
Design Considerations ◽  
Design Variables ◽  
Design Tradeoffs ◽  
Sma Spring ◽  
Important Design

This paper investigates the tradeoffs between design variables important for the development of a mobility support soft exoskeleton for horizontal shoulder adduction. The soft exoskeleton utilizes discreet shape memory alloy (SMA) spring actuators to generate the required torque to move the arm segment, while preserving the qualities of a soft, wearable garment solution. A pilot benchtop test involving varying power input, actuator anchor position, actuator orientation, and added weight, was investigated to evaluate their effects against the degree of motion the soft exoskeleton allows. The results show that the power input, actuator anchor position, and simulated limb weight each affect the ultimate horizontal adduction angle the exoskeleton is able to induce. Further, the project highlights a crucial point in regard to the tradeoffs between functionality and wearability: when actuator orientation was investigated, we found a decrement in functionality (as measured by maximum achievable horizontal adduction angle) when the actuators were constrained close to the body. This shows that when aiming to improve the hypothetical system’s wearability/usability, the effective torque that can be generated is reduced. Together these findings demonstrate important design considerations while developing a wearable, soft exoskeleton system that is capable of effectively supporting movement of the body while maintaining the comfort and discreetness of a regular garment.

scholarly journals Perceived Facilitators and Barriers to Engaging with a Digital Intervention among Those with Food Insecurity, Binge Eating, and Obesity

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2458
Author(s):  
Anu Venkatesh ◽  
Angela Chang ◽  
Emilie A. Green ◽  
Tianna Randall ◽  
Raquel Gallagher ◽  
...  
Keyword(s):  
Binge Eating ◽  
Food Insecurity ◽  
Future Research ◽  
Grocery Stores ◽  
User Centered Design ◽  
Design Considerations ◽  
Digital Intervention ◽  
Intervention Cost ◽  
Facilitators And Barriers ◽  
Important Design

Interventions that address binge eating and food insecurity are needed. Engaging people with lived experience to understand their needs and preferences could yield important design considerations for such interventions. In this study, people with food insecurity, recurrent binge eating, and obesity completed an interview-based needs assessment to learn facilitators and barriers that they perceive would impact their engagement with a digital intervention for managing binge eating and weight. Twenty adults completed semi-structured interviews. Responses were analyzed using thematic analysis. Three themes emerged. Participants shared considerations that impact their ability to access the intervention (e.g., cost of intervention, cost of technology, accessibility across devices), ability to complete intervention recommendations (e.g., affordable healthy meals, education to help stretch groceries, food vouchers, rides to grocery stores, personalized to budget), and preferred intervention features for education, self-monitoring, personalization, support, and motivation/rewards. Engaging people with lived experiences via user-centered design methods revealed important design considerations for a digital intervention to meet this population’s needs. Future research is needed to test whether a digital intervention that incorporates these recommendations is engaging and effective for people with binge eating and food insecurity. Findings may have relevance to designing digital interventions for other health problems as well.

scholarly journals Fluid–Structure Coupling Effects in a Dual U-Tube Coriolis Mass Flow Meter

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 982
Author(s):  
Yuh-Chung Hu ◽  
Zen-Yu Chen ◽  
Pei-Zen Chang
Keyword(s):  
Product Design ◽  
Dynamic Balance ◽  
Fluid Viscosity ◽  
Fluid Structure ◽  
Development Platform ◽  
Design Considerations ◽  
Manufacture Process ◽  
Coupling Dynamics ◽  
Comsol Simulation ◽  
Important Design

Coriolis mass flowmeters are highly customized products involving high-degree fluid-structure coupling dynamics and high-precision manufacture. The typical delay from from order to shipment is at least 4 months. This paper presents some important design considerations through simulation and experiments, so as to provide manufacturers with a more time-efficient product design and manufacture process. This paper aims at simulating the fluid-structure coupling dynamics of a dual U-tube Coriolis mass flowmeter through the COMSOL simulation package. The simulation results are experimentally validated using a dual U-tube CMF manufactured by Yokogawa Co., Ltd. in a TAF certified flow testing factory provided by FineTek Co., Ltd. Some important design considerations are drawn from simulation and experiment. The zero drift will occur when the dual U-tube structure is unbalanced and therefore the dynamic balance is very important in the manufacturing of dual U-tube CMF. The fluid viscosity can be determined from the driving current of the voice coil actuator or the pressure loss between the inlet and outlet of CMF. Finally, the authors develop a simulation application based on COMSOL’s development platform. Users can quickly evaluate their design through by using this application. The present application can significantly shorten product design and manufacturing time.

scholarly journals Development of Subcarangiform Bionic Robotic Fish Propelled by Shape Memory Alloy Actuators

2021 ◽  
Vol 71 (1) ◽  
pp. 94-101
Author(s):  
M. Muralidharan ◽  
I.A. Palani
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Kinematic Model ◽  
Open Loop ◽  
Robotic Fish ◽  
Water Medium ◽  
Light Weight ◽  
Caudal Fin ◽  
Locomotion Pattern ◽  
Sma Spring

In this paper, a shape memory alloy (SMA) actuated subcarangiform robotic fish has been demonstrated using a spring based propulsion mechanism. The bionic robotic fish developed using SMA spring actuators and light weight 3D printed components can be employed for under water applications. The proposed SMA spring-based design without conventional motor and other rotary actuators was able to achieve two-way shape memory effect and has reproduced the subcarangiform locomotion pattern. The positional kinematic model has been developed and the dynamics of the proposed mechanism were analysed and simulated using Automated Dynamic Analysis of Mechanical Systems (ADAMS). An open loop Arduino-relay based switching control has been adopted to control the periodic actuation of the SMA spring mechanism. The undulation of caudal fin in air and water medium has been analysed. The caudal fin and posterior body of the developed fish prototype have taken part in undulation resembling subcarangiform locomotion pattern and steady swimming was achieved in water with a forward velocity of 24.5 mm/s. The proposed design is scalable, light weight and cost effective which may be suitable for underwater surveillance application.

An Approximate Analysis of Foundation Stresses in Horizontal Pressure Vessels

1980 ◽  
Vol 102 (3) ◽  
pp. 555-557
Author(s):  
Krishna P. Singh ◽  
V. K. Luk
Keyword(s):  
Solution Procedure ◽  
Pressure Vessels ◽  
Approximate Analysis ◽  
Loading Conditions ◽  
Mechanical Loads ◽  
Design Considerations ◽  
Desirable Feature ◽  
Horizontal Pressure ◽  
Linear Manner ◽  
Important Design

Saddle supports of horizontally mounted pressure vessels, when subject to seismic and mechanical loads, interact with the foundation in a highly non-linear manner. The maximum foundation concrete pressure, and hold-down bolt stresses are important design considerations which often govern the vessel support geometry. A method is given herein to determine the foundation stresses due to arbitrary imposed loadings. The solution procedure lends itself easily to automated computation—a highly desirable feature—since most nuclear equipment has to be analyzed for a large number of loading conditions.

Climate Geoengineering and the Role of Public Deliberation: A Comment on the us National Academy of Sciences’ Recommendations on Public Participation

Climate Law ◽  
2015 ◽  
Vol 5 (2-4) ◽  
pp. 252-294 ◽  
Author(s):  
William C. G. Burns ◽  
Jane A. Flegal
Keyword(s):  
Public Participation ◽  
Public Deliberation ◽  
National Academy Of Sciences ◽  
World Community ◽  
Design Considerations ◽  
The Us ◽  
The World ◽  
Academy Of Sciences ◽  
Important Design

The feckless response of the world community to the mounting threat of climate change has led to a growing interest in climate geoengineering research. In early 2015, the us National Academy of Sciences released two major reports on the topic. While it is notable that both reports recommended some form of public participation to inform research, this article argues that the vagueness of these recommendations could mean that their implementation might not comport with optimal approaches for public deliberation. We outline some options for public deliberation on climate geoengineering and important design considerations.

Design of a 2 DOF Shape Memory Alloy Actuator Using SMA Springs

2021 ◽  
Author(s):  
Hussein F. M. Ali ◽  
Youngshik Kim
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Open Loop ◽  
Degree Of Freedom ◽  
Biologically Inspired ◽  
Loop Control ◽  
Actuator System ◽  
Sma Actuator ◽  
Sma Spring ◽  
Two Degree Of Freedom

Abstract In this paper, we developed two degree of freedom shape memory alloy (SMA) actuator using SMA springs. This module can be applied easily to various applications: device holder, artificial finger, grippes, fish robot, and many other biologically inspired applications, where small size and small wight of the actuator are very critical. This actuator is composed of two sets of SMA springs: one set is for the rotation around the X axis (roll angle) and the other set is for the rotation around the Y axis (pitch angle). Each set contains two elements: one SMA spring and one antagonistic SMA spring. We used an inertia sensor (IMU) and two potentiometers for angles feedback. The SMA actuator system is modeled mathematically and then tested experimentally in open-loop and closed-loop control. We designed and experimentally tuned a proportional integrator derivative (PID) controller to follow the set points and to track the desired trajectories. The main goal of the presented controller is to control roll and pitch angles simultaneously in order to satisfy set points and trajectories within the work space. The experimental results show that the two degree of freedom SMA actuator system follows the desired setpoints with acceptable rise time and overshoot.

Biomimetic Microsystems for Cardiovascular studies

2021 ◽  
Author(s):  
Shelby C. Inbody ◽  
Bridgett E Sinquefield ◽  
Joshua P. Lewis ◽  
Renita E. Horton
Keyword(s):  
Basic Structure ◽  
Structural Features ◽  
The Body ◽  
Dynamic Features ◽  
Culture Methods ◽  
Implementation Challenges ◽  
Design Considerations ◽  
Drug Studies ◽  
Cell Culture Methods

Tissue culture platforms have been around for several decades and have enabled numerous key findings in the cardiovascular field. However, these platforms fail to recreate the mechanical and dynamic features found within the body. Organs-on-chips (OOCs) are cellularized microfluidic based devices that can mimic the basic structure, function, and responses of organs. These systems have been successfully utilized in disease, development, and drug studies. OOCs are designed to recapitulate the mechanical, electrical, chemical, and structural features of the in vivo microenvironment. Here, we review cardiovascular-themed OOC studies, design considerations, and techniques used to generate microtissues within these devices. Further, we will highlight the advantages of OOCs over traditional cell culture methods, discuss implementation challenges, and provide perspectives on the state of the field.

A shape memory alloy–actuated soft crawling robot based on adaptive differential friction and enhanced antagonistic configuration

2020 ◽  
Vol 31 (16) ◽  
pp. 1920-1934 ◽  
Author(s):  
Chen Liang ◽  
Yongquan Wang ◽  
Tao Yao ◽  
Botao Zhu
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Stride Length ◽  
Parametric Design ◽  
Thermoplastic Polyurethane ◽  
Interaction Mechanism ◽  
Experimental Tests ◽  
The Body ◽  
3D Printed ◽  
Miniature Robot

This article presents a soft crawling robot prototype with a simple architecture inspired by inchworms. The robot functionally integrates the torso (body) and feet in a monolithic curved structure that only needs a single shape memory alloy coil and differential friction to actuate it. A novel foot configuration is proposed, which makes the two feet, with an anti-symmetrical friction layout, can be alternately anchored, to match the contraction–recovery sequence of the body adaptively. Based on the antagonistic configuration between the shape memory alloy actuator and the elastic body, a vertically auxiliary spring was adopted to enhance the interaction mechanism. Force and kinematic analysis was undertaken, focusing on the parametric design of the special foot configuration. A miniature robot prototype was then 3D-printed (54 mm in length and 9.77 g in weight), using tailored thermoplastic polyurethane elastomer as the body material. A series of experimental tests and evaluations were carried out to assess its performance under different conditions. The results demonstrated that under appropriate actuation conditions, the compact robot prototype could accomplish a relative speed of 0.024 BL/s (with a stride length equivalent to 27% of its body length) and bear a load over five times to its own weight.

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