Shape memory alloy (SMA) based actuators have a number of attributes which make them useful for robotic applications. Unfortunately their response is relatively slow, being limited by the speed with which the SMA can be heated and cooled. This paper describes two novel developments of the basic SMA actuator which improve dynamic performance. To allow rapid heating of the shape memory alloy wire...

The main purpose of this paper is to study the solution behavior of the transient heat transfer problem for one-dimensional symmetric thermoelectric shape memory alloy (SMA) actuators. It is proved that for the transient cooling problem with constant electric current density of magnitude |J | there is a value J0 of |J | such that when |J | < J0, the temperature in SMA is always decreasing to it...

Shape Memory Alloy (SMA) actuators are an effective way to reduce weight and to minimize the complexity of various systems including biomedical and more specifically. Prosthesis systems. As actuators, these materials have been used in a wide range of applications from thin film actuators to helicopter rotor actuators [1]. SMA actuators provide an interesting alternative to conventional actuatio...

Shape memory alloy (SMA) actuation is becoming an increasingly viable technology for industrial applications as many of the technical issues that have limited its use are being addressed (speed of actuation, mechanical connections, performance degradation, quality control, etc.) while increasing production capacities drive costs to practical levels. Shape memory alloys are often selected becaus...

This paper introduces a robotic technology-based supporting device, the robot mask, to enhance facial expressiveness and support physiotherapy for facial paralysed persons. The wearable device, which consists of shape memory alloy (SMA)-based linear actuators, functions by pulling the facial skin towards anatomically selected directions. Since facial expressions are silent, SMA was selected ove...

This paper presents low-profile torsional actuators applicable for mesoscale and microscale robots. The primary actuator material is thermally activated Ni–Ti shape memory alloy (SMA), which exhibits remarkably high torque density. Despite the advantages of SMAs for actuator applications—high strain, silent operation, and mechanical simplicity—the response time and energy efficiency limit overa...

Thermally activated shape memory alloy (SMA) actuators are direct-driven and produce high power density with design versatility. However, beyond their linear actuation in spring forms there is little variety and their application in robotics is limited by the challenging characterization of the actuator. In this paper we introduce a novel low-profile torsional SMA actuator design, and its compr...

Prestrainend shape memory alloys (SMA) change their length when heated above their transformation temperature. Based on this property this paper presents the design of macroscopic SMA actuators scalable in force and length that keeps up a short cool down time to guarantee a high frequency of contraction/stress cycles and the possibility of arranging the fixings in any direction. A new model of ...