Development of a Novel Micro-Actuator Driven by Shape Memory Alloy

Abstract

This paper presents a novel microactuator driven by shape memory alloy (SMA). First, the helical spring-shaped SMA is fabricated from SMA wire (Ti50%-Ni45%-Cu5%) with one way shape memory effect and 0.6 mm in diameter. Subsequently, a compliant tube-type microactuator driven by helical spring-shaped SMA is developed. The performances of the helical spring-shaped SMA and the compliant tube-type microactuator, such as the response time, the recovery force and the surface temperature in terms of the driving currents, are investigated. The driving circuit system comprising a pulse width modulation (PWM) control circuit is used to drive the actuator. Experiments demonstrate that control of the SMA actuator using PWM effectively reduces the energy consumption and ensures a short cooling time to guarantee a high response time in actuating cycles. Finite element software (COSMOSWorks) is applied for the analysis of the compliant tube-type actuator, which aim is to demonstrate the agreement between the theoretical analysis and experiment as well as to improve the performance of the actuators.

Development of Novel Actuating Mechanisms for Smart Artificial Flowers

“…The presentation of this research is mainly based on our previous researches [21][22][23][24]. The "smart artificial flower" represents the flower that is able to interact with the surrounding such as temperature, humidity, voice and light intensity, and to show dynamic visual effects such as the blooming of flower, the swaying of stem just like light tracking of the sunflower.…”

“…2) is fabricated for the blooming of the petals and swaying of the stems. Fabrication process steps for the helical spring-shaped SMA and the performance measurement can be referred to [21][22][23][24].…”

Development of dynamically artificial flowers driven by shape memory alloy and pulse width modulation

“…15) in previous papers [16,17], a tube-type actuator with 3 D.O.F of deflections is proposed (Fig. 16a,b).…”

“…There are several modulation techniques, such as pulse width modulation (PWM) [18] and pulse width pulse frequency (PWPF) modulation [19]. In our previous paper [16,17] presents the experimental results of control of SMA actuator using PWM to generate a high response time in acting cycle and reduce energy consumed by the SMA actuator.…”

“…the compliant-tube type actuator in previous paper[16,17], 16a,b (a)Schematic diagram of a tube-type actuator with 3 D.O.F of deflections, and (b) display one of its deflection Figure 17 Prototype of the stem packaged with the 3 D.O.F tube-type actuators IV. DRIVE AND MEASUREMENT OF THE SMA ACTUATOR…”