A Compliant Mechanism Design for Refreshable Braille Display Using Shape Memory Alloy

2015 ◽  
Author(s):  
Pulkit Sapra ◽  
Ankit Kumar Parsurampuria ◽  
Dhruv Gupta ◽  
Suman Muralikrishnan ◽  
Mayank Raj ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Compliant Mechanism ◽  
Low Cost ◽  
Heat Accumulation ◽  
Refresh Rate ◽  
Visually Impaired People ◽  
High Power Consumption ◽  
Braille Literacy ◽  
Braille Display

Refreshable Braille Display (RBD) is a device that enables people with visual imparity to read digital text through tactile interface. Braille literacy is essential for empowerment of visually impaired people and offers several advantages over auditory aids. Commercially available RBDs have not been able to penetrate the market due to their high cost. Shape memory alloy (SMA) based Braille display is a low cost alternative but faces the challenge of high power consumption, heat accumulation and low refresh rate. This paper discusses the design, analysis and experimental validation of a cantilever based compliant mechanism for SMA based RBD to solve these issues.

Refreshable Braille Display Using Shape Memory Alloy With Latch Mechanism

2017 ◽  
Author(s):  
Pulkit Sapra ◽  
Ankit Kumar Parsurampuria ◽  
Suman Muralikrishnan ◽  
Varan Gupta ◽  
H. Karthikeyan ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Response Time ◽  
Shape Memory ◽  
High Power ◽  
Low Cost ◽  
Developing Nations ◽  
Heat Accumulation ◽  
High Power Consumption ◽  
Textual Content ◽  
Braille Display

Refreshable Braille Display (RBD) is a device that enables people with blindness to access digital textual content through tactile interface. The use of commercially available RBDs is restricted to affluent individuals and organizations due to their high cost, which restricts their penetration in developing nations. Braille displays based on shape memory alloy actuators are a potential low cost alternative but face the challenge of high power consumption, heat accumulation and low response time. This paper proposes an SMA based actuator with a novel latching mechanism to make RBDs. It also discusses the design and production challenges addressed in making the RBD. It further compares the performance of the current prototypes with previous designs of SMA based RBDs.

Application of Shape Memory Alloy (SMA) Based Actuation for Refreshable Display of Braille

2013 ◽  
Author(s):  
Anshul Singhal ◽  
Pranay Jain ◽  
Piyush Chanana ◽  
Dhruv Jain ◽  
Rohan Paul ◽  
...  
Keyword(s):  
Developing Countries ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Speech Synthesis ◽  
Low Cost ◽  
Synthetic Speech ◽  
Piezoelectric Actuation ◽  
Tactile Displays ◽  
Braille Character ◽  
Braille Display

Persons with blindness access computers with the help of refreshable Braille displays and speech synthesis softwares. Braille has distinguished advantages over synthetic speech, especially because of its important role in uplifting education, employment and income. However, commercially available Braille displays are typically priced in the range of 2500–4000 USD (65–100 USD per Braille character) and are thus inaccessible to users in both developed and developing countries. Development of affordable Braille displays is thus a critical need. Shape Memory Alloy (SMA) based actuation is a potential low-cost alternative to currently employed piezoelectric actuation, and is being used here to develop an affordable Braille display. This paper discusses key challenges identified in SMA based actuation and proposes methods to overcome the same. Prior attempts at developing tactile displays employing SMA based actuation are reviewed and important considerations for the present study are drawn. The configuration and the design of the actuator are thus arrived at. This paper further discusses the performance of fabricated prototypes and the feedback received from limited user trials. It concludes with a discussion on future scope of the work.

Rapid prototyping prosthetic hand acting by a low-cost shape-memory-alloy actuator

2018 ◽  
Vol 21 (2) ◽  
pp. 238-246 ◽  
Author(s):  
Enrique Soriano-Heras ◽  
Fernando Blaya-Haro ◽  
Carlos Molino ◽  
José María de Agustín del Burgo
Keyword(s):  
Shape Memory Alloy ◽  
Rapid Prototyping ◽  
Shape Memory ◽  
Low Cost ◽  
Prosthetic Hand ◽  
Shape Memory Alloy Actuator

A novel smart assistive knee brace incorporated with shape memory alloy wire actuator

2020 ◽  
Vol 31 (13) ◽  
pp. 1543-1556
Author(s):  
Navid Moslemi ◽  
Soheil Gohari ◽  
Farzin Mozafari ◽  
Mohsen Gol Zardian ◽  
Colin Burvill ◽  
...  
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Controller Design ◽  
Compliant Mechanism ◽  
The Body ◽  
Entire Body ◽  
Knee Brace ◽  
Design Concepts ◽  
Feed Forward Controller ◽  
Actuator Design

The knee plays a significant role in locomotion and stability of the entire body through supporting the body weight and assisting the lower body kinematics during walking. However, the knee is at constant risk of becoming weakened due to disease, age, and accidents. One approach to treating weakened knee is wearing an assistive knee brace. To design a clinical knee brace, many factors such as weight and compliant mechanism should be considered. In this study, a novel smart assistive knee brace mechanism incorporated with wire actuators made of shape memory alloys is proposed to ameliorate the issues associated with weight and flexibility of existing brace designs. Unlike earlier studies, the proposed orthosis includes pressure sensor, shape memory actuator, and smart linkage. Furthermore, two distinct shape memory alloy actuator design concepts with improved stiffness are developed, and the best option is chosen systematically and prototyped. The novel mechanism proposed in this research overcomes the weight of the lower limb during swing phase using the combined shape memory alloy actuation and feed-forward controller design. As such, it can be used as a potential replacement to its conventional counterparts when the higher weight reduction as well as a flexible and controllable mechanism are simultaneously sought.

Modelling and simulation of a novel shape memory alloy actuated compliant parallel manipulator

2008 ◽  
Vol 222 (6) ◽  
pp. 1049-1059 ◽  
Author(s):  
M Sreekumar ◽  
T Nagarajan ◽  
M Singaperumal
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Compliant Mechanism ◽  
Linear Analysis ◽  
Structural Member ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Complex Behaviour ◽  
Spatial Parallel Mechanism ◽  
Simulation Results

This paper presents the non-linear analysis of a shape memory alloy (SMA) actuated fully compliant spatial parallel mechanism. A compliant mechanism made of SMA wires as its actuators and SMA pipe as its structural member that exploits both the shape memory and superelastic effects is proposed and its static analysis using ANSYS is presented in this study. Finite element analysis in a multi-physics environment considering geometric and material non-linearities helps the user to analyse complex behaviour of a system. For the proposed mechanism, simulation results show: (a) 4 per cent strain for SMA actuation is optimal considering the geometric non-linearity of the proposed mechanism for obtaining maximum displacement; (b) buckling effect is less predominant while implementing the superelastic behaviour; and (c) the mechanism can be designed as a compliant device with one or more inflexion points by exploiting the superelasticity of the SMA pipe. The knowledge obtained from the simulation study could help in further miniaturization of the manipulator.

Inverse Kinematics - Stewart Platform Actuated by Shape Memory Alloy for Immobilization of Ankle-Foot Rehabilitation

2016 ◽  
Vol 724 ◽  
pp. 105-111 ◽  
Author(s):  
Ahmad Majdi Abdul-Rani ◽  
Subramaniam Krishnan ◽  
T. Nagarajan ◽  
T.V.V.L.N. Rao
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Low Cost ◽  
Medical Application ◽  
Stewart Platform ◽  
Inverse Kinematic ◽  
Continuous Passive Motion ◽  
Original Form ◽  
Base Diameter ◽  
Thermal Changes

In this paper, the analyses results on the behavior of Shape Memory Alloy (SMA) in Medical application were carried out. SMA materials are known by their aptitude to recover its original form when undergone suitable thermal changes. SMA is widely used in robotics, automotive, aerospace and it can be a potential application in biomedical engineering due to its low cost, high corrosion resistance and can be easily integrated with human applications. Stewart platform with two different upper platform diameters of 150 mm and 300 mm were designed, fabricated and used as experimental test-rig. Inverse kinematic calculations were carried out to identify a maximum deflection of Stewart platform that can promote continuous passive motion (CPM). The 150 mm base diameter Stewart platform is found to be the suited for generating substantial displacement between ankle and foot. The mechanical changes induced by the heat could be used as a property in manufacturing of rehabilitation device for foot and ankle.

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