High-displacement fast-cooling flexible Shape Memory Alloy actuator: Application to an anthropomorphic robotic hand

Abstract

This paper presents a novel Shape Memory Alloy (SMA) linear actuator and its application driving the joints of an anthropomorphic robotic hand. Its main feature is that it is a flexible SMA actuator, it is designed so that it can be bent. The possibility of bending the actuator while preserving its capacity to produce a linear movement allows to use very long SMA wires, able to yield a great linear displacement, in a confined space. This feature provides better integration and adaptability than other existing high-displacement SMA actuators. The mechanical design of the presented SMA flexible actuator is based on the Bowden cable transmission system, using a multilayer sheath with a PTFE inner sheath to reduce friction losses and a stainless steel outer sheath that functions as a heat sink to reduce the cooling time of the SMA element. To test the SMA actuator with a real device, a robotic hand has been built using low cost rapid prototyping techniques from an open source design. The designed flexible SMA actuator has a great potential to be used in humanoid robots or robotic prostheses, due to its adaptability, output force, low weight and silent operation.

Characterization and Lubrication of Tube-Guided Shape-Memory Alloy Actuators for Smart Textiles

“…The tube-guided SMA wire actuator concept has been applied to an anthropomorphic robotic hand [21] and to soft wearable robots [22], as well as investigated as a concept for integration of actuators into confined spaces [23]. In those studies, there has been some exploration of the trade-offs associated with the use of tube-guided SMA wire actuators.…”

Sistema Avanzado de Protipado Rápido para Control en la Educación en Ingeniería para grupos Multidisciplinares

“…En la imagen, un grupo de estudiantes compara los resultados del control en simulación con los resultados en la realidad. (Villoslada et al, 2014). Emplea sensores de fuerza en las yemas de los dedos para proporcionar informaciónútil para realizar agarre de objetos.…”

Control systems of rehabilitation engineering equipment — A review

“…Usually, this kind of approach substitutes the need of force and amplitude with actuators (pneumatic [10] [11], electric [12] [13] [14], shape-memory alloys [15] [16] [17], etc.) that are controlled with the use of keyboards, joysticks or microswitches.…”