Shape memory alloy-based high phase order motor

In this paper, we present our current work in the design and characterisation of a new shape memory alloy (SMA)-based High Phase Order Motor (HPOM). The motor can be used either in stepping mode or in servo mode of operation. Each phase of the motor consists of an SMA wire with a spring. The principle of operation of the HPOM is presented. In its operation the motor resembles a stepper motor though the actuation principles are different and hence has been characterised similar to a stepper motor.This motor can be actuated in either direction depending on which SMA is actuated, which are presented in this work. The motor is modelled and simulated and the results of simulations and experiments are presented

Effect of waste plaster of Paris on physical and mechanical properties of ceramic pottery body

Over the years, millions tonnes of waste plaster of Paris (POP) were generated and disposed in landfills or most of the time was dumped directly into the environment without any treatments, makes it as one of the environmental issues. Therefore, a new alternative is required to convert the wastes POP into useful materials and marketable to minimize the environmental impact. In the early stage, this study focused on the characterization of the raw material used through particle size analysis, thermal analysis, and identification of its purity. Then, the slip casting technique and standard American Society for Test and Materials (ASTM) was respectively used to fabricate and characterize all of the pottery samples. In the second stage, the ceramic pottery body was fabricated using different composition of waste POP, started from 0 wt.% until 12 wt.%. The samples obtained were analysed through viscosity test and its green body was observed. The results showed that the samples with compositions of 0 to 10 wt.% of waste POP were the only samples that can be used in this study. The analysis on the effects of particle sizes ranging from 25 to 73 μm and sintering temperatures ranging from 950 to 1050 °C on the physical and mechanical properties of the fabricated ceramic pottery body, respectively, were then determined in the third and fourth stage of this study. The physical properties were reported in terms of shrinkage, porosity, and density values; whereas, the mechanical properties were reported in terms of the value of modulus of rupture (MOR). The result showed that a dense and a high strength of ceramic pottery can be produced by using a finer size of particle of 25 μm and at a high sintering temperature of 1050 °C, based on the low porosity value, the high density value, MOR and also the controllable value of shrinkage. Therefore, it can be concluded that the waste POP can be successfully used as a filler to enhance the properties of ceramic pottery body

Effect of waste plaster of Paris on physical and mechanical properties of ceramic pottery body

Over the years, millions tonnes of waste plaster of Paris (POP) were generated and disposed in landfills or most of the time was dumped directly into the environment without any treatments, makes it as one of the environmental issues. Therefore, a new alternative is required to convert the wastes POP into useful materials and marketable to minimize the environmental impact. In the early stage, this study focused on the characterization of the raw material used through particle size analysis, thermal analysis, and identification of its purity. Then, the slip casting technique and standard American Society for Test and Materials (ASTM) was respectively used to fabricate and characterize all of the pottery samples. In the second stage, the ceramic pottery body was fabricated using different composition of waste POP, started from 0 wt.% until 12 wt.%. The samples obtained were analysed through viscosity test and its green body was observed. The results showed that the samples with compositions of 0 to 10 wt.% of waste POP were the only samples that can be used in this study. The analysis on the effects of particle sizes ranging from 25 to 73 μm and sintering temperatures ranging from 950 to 1050 °C on the physical and mechanical properties of the fabricated ceramic pottery body, respectively, were then determined in the third and fourth stage of this study. The physical properties were reported in terms of shrinkage, porosity, and density values; whereas, the mechanical properties were reported in terms of the value of modulus of rupture (MOR). The result showed that a dense and a high strength of ceramic pottery can be produced by using a finer size of particle of 25 μm and at a high sintering temperature of 1050 °C, based on the low porosity value, the high density value, MOR and also the controllable value of shrinkage. Therefore, it can be concluded that the waste POP can be successfully used as a filler to enhance the properties of ceramic pottery body

Comparison of Different Temperatures on Bending Properties of Six Niti Endodontic File Systems

Introduction: Manufacturers claim that modern NiTi files with proprietary heat treatment transform at higher temperatures, thus staying more martensite and being more resistant to cyclic fatigue and more flexible. There are some studies comparing the effect of body temperature and room temperature on cyclic fatigue of these newer NiTi files. However, there is not yet a study published for evaluating the relationship between bending properties of NiTi instruments and temperature following the ISO 3630-1 guideline. The objective of this study was to evaluate how temperature affects the bending properties of six different brands of NiTi rotary instruments with different transformation temperature ranges. Methods: Six commercially available NiTi files were selected for this experiment. The tested files included K3 40/.04 (Sybron Endo, Orange, CA), ProFile Series 29 Green Size 6 (Dentsply Tulsa Dental Specialties), K3XF 40/.04 (Sybron Endo, Orange, CA), Vortex Blue 40/.04 (Dentsply Tulsa Dental Specialties), ProFile Vortex 40/.04 (Dentsply Tulsa Dental Specialties), and HyFlex CM™ 40/.04 (Coltène/Whaledent Inc., Cuyahoga Falls, OH). The Austenite finish temperatures of the files were 9.6 ± 0.5, 17.6 ± 0.6, 24.9 ± 1.1, 35.4 ± 1.2, 45.7 ± 0.9, and 60.3 ± 3.1, respectively. The bending properties of the files were measured using a torsiometer (Sa bri Dental Enterprises, Inc. Downers Grove IL) following ISO 3630-1 guidelines. Twelve of each file type were grouped into 3 groups based on temperatures. Each temperature group had a total of 72 files. Group 1 measured the bending moment (g.cm) at 9±2°C, group 2 at 23±2°C, and group 3 at 35±2°C. The data was statistically analyzed by ANOVA and post hoc HSD (P\u3c0.05) Results: For all tested files, the bending moment of the files increased as the temperature rose from 9to 23 to 35°C. At all temperatures, HyFlex CM was significantly more flexible than other files. ProFile Vortex, K3XF, and Vortex Blue showed similar flexibility with each other. They were significantly more flexible than ProFile Series 29, which was significantly more flexible than K3. Conclusion: Testing temperature and brand of the files were significant independent variables affecting the flexibility of the files

Development of shape memory metal as the actuator of a fail safe mechanism

A small, compact, lightweight device was developed using shape memory alloy (SMA) in wire form to actuate a pin-puller that decouples the flanges of two shafts. When the SMA is heated it contracts producing a useful force and stroke. As it cools, it can be reset (elongated in this case) by applying a relatively small force. Resistive heating is accomplished by running a current through the SMA wire for a controlled length of time. The electronics to drive the device are not elaborate or complicated, consisting of a timed current source. The total available contraction is 3 percent of the length of the wire. This device, the engineering properties of the SMA, and the tests performed to verify the design concept are described

Torsion and Bending Properties of EdgeEndo Files

Introduction: One important step of root canal therapy is the process of cleaning and shaping each canal. This process involves using endodontic rotary files combined with chemical irrigants to remove pulpal remnants and infected dentin from the canal while eliminating pathogenic bacteria. It is essential to maintain proper canal anatomy while cleaning and shaping. The challenge for the practitioner is to select a rotary file system that will be flexible enough to maintain canal anatomy but strong enough to prevent breakage under normal use. File flexibility allows for better maintenance of canal anatomy. A file’s resistance to torsional fatigue reduces the chance of file breakage. The purpose of this study was to compare the torsion and bending properties of a brand new file system (EdgeFiles by EdgeEndo, Albuquerque, NM) marketed as being twice as strong but half the price compared to other marketed files Materials and Methods: Thirty files of each type were used. Ten different files systems were evaluated. Size 30 files of .04 taper EdgeFile X7, EdgeFile X5, EndoSequence (Brasseler), Vortex Blue (Dentsply), GT Series X (Dentsply), K3XF (SybronEndo), HyFlex CM (Coltene/Whaledent, Inc.), and .06 taper EdgeFile X3 (EdgeEndo), ProTaper Universal (Dentsply), ProTaper Gold (Dentsply). Testing was done with a torsiometer following ISO 3630-1. Twelve of each file type were evaluated for bending and 18 of each type were evaluated with torsion. Results were separated into 3 different groups due to differences in file design. Group 1 included X3, Protaper Universal, and Protaper Gold. Group 2 included X5 and GT series X. Group 3 included X7, EndoSequence, Vortex Blue, K3XF, and HyFlex CM. Results: In Group 1, X3 showed the most flexibility followed by ProTaper Gold then ProTaper Universal. For strength, ProTaper Gold had the highest resistance to torsion followed by ProTaper Universal then X3. In Group 2, X5 showed more flexibility while GTX had higher strength. In Group 3, HyFlex CM showed the most flexibility followed by X7, then EndoSequence, Vortex Blue, and finally K3XF. For strength, K3XF was highest. X7 and Vortex Blue had similar values which were higher than HyFlex CM followed by EndoSequence. Conclusion: An overall conclusion could be made that strength and flexibility have a relatively inverse relationship in each group. The stronger files tend to be less flexible and the more flexible files tend to be more susceptible to torsional failure. ProTaper Gold and X7 had the best combinations of strength and flexibility

A Review of Smart Materials in Tactile Actuators for Information Delivery

As the largest organ in the human body, the skin provides the important sensory channel for humans to receive external stimulations based on touch. By the information perceived through touch, people can feel and guess the properties of objects, like weight, temperature, textures, and motion, etc. In fact, those properties are nerve stimuli to our brain received by different kinds of receptors in the skin. Mechanical, electrical, and thermal stimuli can stimulate these receptors and cause different information to be conveyed through the nerves. Technologies for actuators to provide mechanical, electrical or thermal stimuli have been developed. These include static or vibrational actuation, electrostatic stimulation, focused ultrasound, and more. Smart materials, such as piezoelectric materials, carbon nanotubes, and shape memory alloys, play important roles in providing actuation for tactile sensation. This paper aims to review the background biological knowledge of human tactile sensing, to give an understanding of how we sense and interact with the world through the sense of touch, as well as the conventional and state-of-the-art technologies of tactile actuators for tactile feedback delivery

Micro-Actuators and Implementation

Miniaturization of devices inculcates the need for small-sized actuators. Actuators in the size of a few centimeters are not uncommon but miniature devices need ones that are less than a few centimeters in dimension. Market for such actuators is rather small and information pertaining to their implementation is limited. This paper talks about various actuators and their actuation mechanism for the design of small-scale electronic devices. Not only are the small-sized actuators used for designing miniature devices, but also used for precise movements in the range of a few millimeters. We have included a procedure-wise description on how to implement these actuators. An in-depth analysis of their mechanical, electrical and chemical characteristics is elaborated in this paper