Shape memory alloys are smart materials. Due to their ability to change into a previously imprinted actual shape through the means of thermal activation, they are suitable as actuators for microsystems and, within certain limitations, macroscopic systems. To apply these smart materials to a wide range of industrial applications, a simple method of controlling the actuator effect is required. Th...

With the progress of miniaturization, shape memory alloy (SMA) actuators exhibit high energy density, self-sensing ability and ease of fabrication, which make them well suited for practical applications. This paper presents a self-sensing controlled actuator drive that was designed using antagonistic pairs of SMA wires. Under a certain pre-strain and duty cycle, the stress between two wires bec...

In some systems with hysteresis behavior like Shape Memory Alloy (SMA) actuators and Piezo actuators, we essentially need an accurate modeling of hysteresis either for controller design or performance evaluation. One of the most interesting Hysteresis non-linearity identification methods is Preisach model in which hysteresis is modeled by linear combination of elemental operators. Despite good ...

This paper presents a shape memory alloy (SMA) ac-tuator aimed to be integrated in the phalanx of a dex-terous micro-gripper. Its original design mechanically decouples motion transmission from force transmission. After a brief discussion on the operating principles of the actuator, the kinematics of the mechanism and its general features are speciied. A thermo-mechanical model of the SMA bers ...

Inspired by its simple musculature, actuation and motion mechanisms, we have developed a small crawling robot that closely mimics the model organism of our choice: Caenorhabditis elegans. A thermal shape memory alloy (SMA) was selected as an actuator due to the similarities of its properties to C. elegans muscles. Based on the anatomy of C. elegans, a 12-unit robot was designed to generate a si...

Experimental results are presented to show that SMA actuators are able to control forces both rapidly and precisely. An antagonistic pair of constrained actuators is shown to be capable of rapidly changing the setpoint throughout a 7.00 N range. Although the system entered into a limit cycle at the setpoint, the limit cycle magnitude was small. The peak to peak amplitude of the limit cycles was...

A novel Shape Memory Alloy (SMA) actuator consisting of a number of thin NiTi bers woven in a counter rotating helical pattern around supporting disks is rst described. This structure can be viewed as a parallel mechanism used to accomplish a highly e cient transformation between force and displacement. The actuator overcomes the main mechanical drawback of shape memory alloys, that being limit...

The in-pipe robots play significant role for applications like inspection of pipes or wearing of cables and materials, etc. The paper deals with motion analysis of in-pipe robot, whose actuator is based on shape memory effect. At first, the principle of motion and design solution of experimental in-pipe robot is introduced. Then the mathematical model is establish by means of Newton ́s mechanics...

A novel Shape Memory Alloy (SMA) actuator consisting of a number of thin NiTi bers woven in a counter rotating helical pattern around supporting disks is rst described. This structure can be viewed as a parallel mechanism used to accomplish a highly ee-cient transformation between force and displacement. The actuator overcomes the main mechanical drawback of shape memory alloys, that being limi...