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.

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.

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.

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

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.

Analytical investigation of the behavior of a new smart recentering shear damper under cyclic loading

2019 ◽  
Vol 31 (4) ◽  
pp. 550-569 ◽  
Author(s):  
Nadia M Mirzai ◽  
Reza Attarnejad ◽  
Jong Wan Hu
Keyword(s):  
Energy Dissipation ◽  
Cyclic Loading ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Passive Control ◽  
Shear Failure ◽  
Low Cost ◽  
Residual Deformation ◽  
Friction Damper ◽  
Element Analysis

Shear recentering polyurethane friction damper is a type of passive control device, including the shape memory alloy plates, polyurethane springs, and friction devices. This damper can be employed in the shear link of an inverted Y-shaped braced frame. As the failure mode is a shear failure, in this study, the shear recentering polyurethane friction damper is proposed to remove the residual deformation of the structure that remains after a strong earthquake and causes considerable damage to the structure. The shear recentering polyurethane friction damper can help the structure to return to the initial position. Furthermore, as compared to many other dampers, this new damper is of low cost, and its assembling requires a simple technology. In order to evaluate the performance of the damper, four different cases are considered. Furthermore, the effect of each component is investigated in each case, and a finite element analysis is performed under cyclic loading using the ABAQUS platform. In addition, for the sake of comparison, the shape memory alloy plates are replaced by steel ones, and a comparison for the results demonstrates that the recentering shear dampers can significantly decrease residual deformation, while there is a large amount of residual deformation in the steel damper. Due to using the polyurethane springs, the ultimate capacity of the shear shape memory alloy polyurethane friction damper is 500 kN; however, in the shear steel polyurethane friction damper, it is only about 300 kN. Furthermore, the energy dissipation by the shear shape memory alloy polyurethane friction damper is larger than the shear steel polyurethane friction damper. The results show that the steel plates cannot effectively increase energy dissipation.

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