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ABSTRACT: To design effective movement of robots, various locomotive mechanisms have been investigated. In this study, an inchworm robot To design effective movement of robots, various locomotive mechanisms have been investigated. In this study, an inchworm robot
was manufactured using shape memory alloy (SMA) which was embedded in composite materials. A Ni-Ti SMA wire was pre-strained was manufactured using shape memory alloy (SMA) which was embedded in composite materials. A Ni-Ti SMA wire was pre-strained
and embedded in the glass fiber reinforced polymer (GFRP) strip laid on an ∩-shape mold. Then SMA embedded composite structure and embedded in the glass fiber reinforced polymer (GFRP) strip laid on an ∩-shape mold. Then SMA embedded composite structure
was cured at room temperature for 72 hours. Controlling DC current through the SMA wire, the SMA-composite structure, body, was cured at room temperature for 72 hours. Controlling DC current through the SMA wire, the SMA-composite structure, body,
could be actuated by changing the radius of curvature. Two legs were attached to the end of body and the leg has two edges could be actuated by changing the radius of curvature. Two legs were attached to the end of body and the leg has two edges
which have different coefficients of friction to provide directional movement. One stroke of inchworm provided 4.0 mm translational which have different coefficients of friction to provide directional movement. One stroke of inchworm provided 4.0 mm translational
movement. Repeating on and off of DC current, the inchworm robot gives continuous movement. This mechanism can be applied movement. Repeating on and off of DC current, the inchworm robot gives continuous movement. This mechanism can be applied
to the soft morphing robotics, bio medical devices, airplane inlet, etc. instead of using traditional components for their to the soft morphing robotics, bio medical devices, airplane inlet, etc. instead of using traditional components for their
movement. movement.
KeywordsShape memory alloy–Composite–Inchworm–Robot KeywordsShape memory alloy–Composite–Inchworm–Robot
International Journal of Precision Engineering and Manufacturing 04/2012; 12(3):565-568. · 1.14 Impact Factor
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ABSTRACT: Rapid prototyping (RP) is a direct-writing technology that offers several advantages over subtractive manufacturing processing,
including low material consumption and easy customizability. Recently, this technique has been studied not only manufacture
production parts but also electronic manufacturing applications. In this research, the design and manufacture of printed circuits
using RP printing of lead-based alloy having low melting temperature were performed. The bonding strength was measured by
strength test. Average bonding strength between solder and universal printed circuit board (PCB) was 69.5 kPa. A simple electrical
circuit with five crossing points was constructed to reduce the size of the circuit. In the crossing points, polycaprolactone
(PCL) was deposited between top and bottom interconnects to insulate the printed line. Through this process, the size of the
circuit board can be reduced about 34% and the number of processing steps was decreased.
International Journal of Precision Engineering and Manufacturing 04/2012; 10(5):147-150. · 1.14 Impact Factor
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ABSTRACT: Shape memory alloys (SMAs) have been actively studied in many fields utilizing their high energy density. Applying SMA wire-embedded composite to aerospace structures, such as air intake of jet engines and guided missiles, is attracting significant attention because it could generate a comparatively large actuating force. In this research, a scaled structure of SMA wire-embedded composite was fabricated for the air intake of aircraft. The structure was composed of several prestrained Nitinol (Ni–Ti) SMA wires embedded in -shape glass fabric reinforced plastic (GFRP), and it was cured at room temperature for 72 h. The SMA wire-embedded GFRP could be actuated by applying electric current through the embedded SMA wires. The activation angle generated from the composite structure was large enough to make a smart air intake structure.
Physica Scripta 05/2010; 2010(T139):014042. · 1.20 Impact Factor
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ABSTRACT: Using the nano-composite deposition system (NCDS) as a microfabrication technique, implantable scaffolds were prepared with poly(DL-lactide-co-glycolide)(85:15) [PLGA(85:15)] as a biodegradable polymer. 5-Fluorouracil (5-FU) was used as a model drug, and hydroxyapatite (HA) was incorporated as a release modifier. In vitro drug release was evaluated and we confirmed that HA could control the release of drug from the prepared scaffolds, especially in the initial phase of the release. Furthermore, in vivo tests demonstrated that the microfabricated scaffold with pores was useful in reducing immune response and maintained its original shape, indicating that the drug delivery system was highly biocompatible.
Archives of Pharmacal Research 03/2010; 33(3):427-32. · 1.59 Impact Factor
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Microelectronic Engineering - MICROELECTRON ENG. 01/2010; 87(10):2024-2024.
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ABSTRACT: In this study, 3-mum- and 20-nm nickel powders were deposited on Si substrates to pattern a metal line using a nanoparticle deposition system (NPDS) at room temperature. The stand-off distance (SoD), the distance between the substrate and the end of nozzle, was varied from 300 to 1000 mum to determine its effect on deposition properties. A Ni line was successfully formed on the Si substrate. When 3-mum Ni powders were used, the thickness of the deposited layer on the Si substrate was measured to be 5.4 mum, and its width was 176.4 mum at a SoD of 300 mum. In contrast, the deposited average thickness at a SoD of 500 mum was 1.1 mum, with a width of 190.6 mum. Moreover, the deposited thickness was measured to be 6.4 mum using 20-nm Ni powders at a SoD of 300 mum. Thus, it was found that the deposited thickness decreased as SoD increased, indicating an inversely proportional relationship. For deposition behavior, depending on the size of powders, it was found that 20-nm Ni powders resulted in a thicker deposition than did 3-mum Ni powders, as momentum transfer between carrier gas and powders is inversely proportional to the powder size. Thus, as the powder size decreased, its spray velocity increased; hence, it is more effective to use nano powders for Ni line patterning. Surface resistivity of the deposited Ni line was 1.83 × 10-7 Omega\cdotm using 20-nm powders and 1.61 × 10-7 Omega\cdotm using 3-mum powders. These values are close to the standard resistivity value for bulk Ni, which is 6.9 × 10-8 Omega\cdotm, making NPDS a promising technique for metal line-fabrication equipment.
Japanese Journal of Applied Physics 01/2010; 49(5). · 1.06 Impact Factor
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ABSTRACT: Purpose – Rapid prototyping (RP) technology has been widely applied in biomedical research. The purpose of this paper is to describe how a scaffold composite drug delivery system (DDS) was fabricated using a nano composite deposition system (NCDS). Design/methodology/approach – A biocompatible and biodegradable thermoplastic polymer (poly(DL-lactide-co-glycolide acid)) was used as the matrix, and a mixture of anti-cancer drug (5-fluorouracil) and bio-ceramic (hydroxyapatite – HA) was added to the polymer to form a bio-composite material for the DDS. An in vitro drug release test showed that the release rate of the drug composite could be controlled by the amount of HA for 50 days. Findings – Faster release was observed for the DDS with higher weight percent of HA. The relationship between release rate and the amount of HA showed a bi-linear manner, and bi-linear drug release models were developed based on the experimental results. Originality/value – Cylindrical scaffolds were fabricated with polymer/drug/additive using an NCDS. A series of in vitro drug release tests was performed to evaluate the effectiveness of the additive, HA. Drug release models were developed based on the experimental results.
Rapid Prototyping Journal 09/2008; 14(5):293-299. · 1.02 Impact Factor
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ABSTRACT: PLGA scaffolds were prepared using a nano-composite deposition system (NCDS). 5-Fluorouracil (5-FU) was used as a model drug. Hydroxyapatite (HA) was included in the scaffolds to improve the mechanical properties of the scaffolds and modulate the release of 5-FU from the scaffolds. 5-FU and HA were dispersed well in the prepared scaffolds when evaluated with SEM, FT-IR, XRPD and DSC. The release of 5-FU from the prepared scaffolds consisting of different compositions was determined using 40 mL PBS as the medium. The release profiles of 5-FU from PLGA scaffolds followed the typical triphasic release pattern. The addition of HA to the compositions increased the release rate of 5-FU from the scaffolds and improved the mechanical properties of the scaffolds, while it retarded the degradation of PLGA. Therefore, NCDS could be a good system to prepare polymeric implants of various shapes with different drug release patterns.
Archives of Pharmacal Research 02/2008; 31(1):125-32. · 1.59 Impact Factor
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Macromolecular Research - MACROMOL RES. 01/2008; 16(5):396-398.
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ABSTRACT: In this paper, web-based micromachining systems are compared with a commercial CAD/CAM system from the point of educational usability. The web-based systems included in this study were MIcromachining System (MIMS) and SmartFab. In the MIMS architecture, a 3D model in STL format was read using the web browser, the file was sent to the web server where toolpath planner was located, and the NC code was reviewed by the designer through the web connection. In the SmartFab system, SolidWorks was used as the design interface with modified menus that support input parameters for micromachining. This additional function was available by SolidWorks API that provided links to the same toolpath planner as MIMS. In the commercial CAD/CAM case, without using any web connection, SolidWorks and CATIA were used for design, and PowerMill was used as a CAM tool. For each system, accessibility, user-friendliness, toolpath-reliability, and processing time were compared. Total of 91 students tested these systems in an undergraduate CAD class, and the user's feedback showed better performance of the web-based system in accessibility, user-friendliness, and processing time. However, reliability of the web-based system should be improved to be more useful design and manufacturing system. © 2006 Wiley Periodicals, Inc. Comput Appl Eng Educ 14: 169–177, 2006; Published online in Wiley InterScience (www.interscience.wiley.com); DOI 10.1002/cae.20076
Computer Applications in Engineering Education 09/2006; 14(3):169 - 177. · 0.33 Impact Factor
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Int. J. Computer Integrated Manufacturing. 01/2005; 18:251-259.
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ABSTRACT: Education using Internet has been expended together with the overall growth and expansion of Internet technologies. A number of Internet-based educational tools have been developed to support mechanical education. However, many of these tools have limitations being mostly just visual assistant tools for understanding engineering principles. From the point of view of life-long engineering education, which are based on the engineering principles and can be used in the field, more advanced functionalities are required. In this sense, Internet-based design and manufacturing tools were developed. Web-based design and manufacturing system for micro fabrication provides important information of design for manufacturing from the database, reduces cost and time in process from design to manufacturing. Internet-based tolerance service system provides a convenient input environment and supports decision-making for proper positional tolerance by using dynamic tolerance diagram in a basic hole-and shaft system which requires assembly between two plates having two holes and two shafts, respectively. Based on Internet technology, they have good accessibility and are familiar to users.
