Design of variable stiffness fixture for computerized embroidery machine based on shape memory polymer

2022 ◽  
pp. 1045389X2110721
Author(s):  
Yawen Yang ◽  
Lei Tian ◽  
Xi Chen ◽  
Jiayuan Wang ◽  
Yongyan Zhang ◽  
...  
Keyword(s):  
Shape Memory ◽  
Material Properties ◽  
Room Temperature ◽  
Working Condition ◽  
Raw Materials ◽  
Shape Memory Polymer ◽  
Variable Stiffness ◽  
Fixture Design ◽  
Stiffness Characteristic ◽  
The Relationship

It is a challenge to handle the metal fixture used for cloth clamping in a computerized embroidery machine because of its fixed stiffness. Herein, a prototype that acts as a fixture to provide variable stiffness property is explored by discussing the potential of a thermal-sensitive epoxy resin-based shape memory polymer (SMP). The general model of fixture design is obtained after analyzing the working condition of the metal fixture. The structure of the SMP fixture is designed by discussing the material properties and working requirements of SMP, and a theoretical model is established to deduce the relationship between thickness and stiffness of the fixture. Six SMP fixtures that memorized clamping and opening state were manufactured with different proportions of raw materials. The results show that the designed fixtures have a lighter weight but higher clamping force than the metal fixture at room temperature (RT). It is the first work that demonstrates the potential of the SMP fixture to replace the metal fixture in the computerized embroidery machine and provides inspiration for product design with variable stiffness characteristic in engineering.

Characristics of Shape Memory Composites Combined with Shape Memory Alloy and Shape Memory Polymer

2013 ◽  
Vol 705 ◽  
pp. 169-172
Author(s):  
Xue Feng ◽  
Li Min Zhao ◽  
Xu Jun Mi
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Young Modulus ◽  
Thermomechanical Properties ◽  
The Matrix ◽  
Shape Memory Composites ◽  
Shape Fixity

In order to develop high functionality of shape memory materials, the shape memory composites combined with TiNi wire and shape memory epoxy were prepared, and the mechanical and thermomechanical properties were studied. The results showed the addition of TiNi wire increased the Young modulus and breaking strength both at room temperature and at elevated temperature. The composites maintained the rates of shape fixity and shape recovery close to 100%. The maximum recovery stress increased with increasing TiNi wire volume fraction, and obtained almost 3 times of the matrix by adding 1vol% TiNi wire.

scholarly journals Mechanically Robust, Softening Shape Memory Polymer Probes for Intracortical Recording

Micromachines ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 619 ◽  
Author(s):  
Allison Stiller ◽  
Joshua Usoro ◽  
Jennifer Lawson ◽  
Betsiti Araya ◽  
María González-González ◽  
...  
Keyword(s):  
Shape Memory ◽  
Room Temperature ◽  
Shape Memory Polymer ◽  
Microelectrode Arrays ◽  
Device Fabrication ◽  
High Modulus ◽  
Mechanical Instability ◽  
Rat Cortex ◽  
Clinical Scenarios ◽  
Stiff Material

While intracortical microelectrode arrays (MEAs) may be useful in a variety of basic and clinical scenarios, their implementation is hindered by a variety of factors, many of which are related to the stiff material composition of the device. MEAs are often fabricated from high modulus materials such as silicon, leaving devices vulnerable to brittle fracture and thus complicating device fabrication and handling. For this reason, polymer-based devices are being heavily investigated; however, their implementation is often difficult due to mechanical instability that requires insertion aids during implantation. In this study, we design and fabricate intracortical MEAs from a shape memory polymer (SMP) substrate that remains stiff at room temperature but softens to 20 MPa after implantation, therefore allowing the device to be implanted without aids. We demonstrate chronic recordings and electrochemical measurements for 16 weeks in rat cortex and show that the devices are robust to physical deformation, therefore making them advantageous for surgical implementation.

HREM observation of interface between precipitates and martensite of reversible shape memory alloy Ni-Ti

1991 ◽  
Vol 49 ◽  
pp. 596-597
Author(s):  
Zhiyi Song ◽  
Hatsujiro Hashimoto ◽  
Eiichi Sukedai
Keyword(s):  
Electron Microscopy ◽  
Shape Memory ◽  
Room Temperature ◽  
Atomic Scale ◽  
Martensitic Transformation Temperature ◽  
Microscopy Observation ◽  
Resolution Electron ◽  
Interface Structures ◽  
The Relationship ◽  
Martensite Structure

Since the reversible shape memory (RSM) alloys were found in 1960, a number of investigations and applications have been carried out and the mechanism have been discussed extensively. Ni-Ti is one of the typical RSM alloys. Many researches were concentrated on martensite structure and the relationship between martensite and austenite. However, the interface structures between martensite and precipitates have been rarely studied. In the present paper, the interface structures between precipitates ( NiTi2 and Ni3Ti) and martensite were investigated in atomic scale by using nigh resolution electron microscopy.49.5at%Ni-50.5at%Ti alloy whose martensitic transformation temperature is 75°C was annealed at 900°C for 2 hours to allow the components to become uniformly distributed, then quenched into water at room temperature. The specimens for electron microscopy observation were prepared by spark cutting and electropolishing. A JEM-2000EX and JEM-4000EX operated at 200kv and 400kv, respectively were used in the present observations.

scholarly journals Variable stiffness corrugated composite structure with shape memory polymer for morphing skin applications

2017 ◽  
Vol 26 (3) ◽  
pp. 035052 ◽  
Author(s):  
Xiaobo Gong ◽  
Liwu Liu ◽  
Fabrizio Scarpa ◽  
Jinsong Leng ◽  
Yanju Liu
Keyword(s):  
Shape Memory ◽  
Composite Structure ◽  
Shape Memory Polymer ◽  
Variable Stiffness

Towards Novel Light-Activated Shape Memory Polymer: Thermomechanical Properties of Photo-responsive Polymers

2005 ◽  
Vol 872 ◽  
Author(s):  
Emily A. Snyder ◽  
Tat H. Tong
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Room Temperature ◽  
Shape Memory Polymer ◽  
Crosslinking Density ◽  
Material System ◽  
Effect Change ◽  
Responsive Polymers ◽  
Original Shape

AbstractThe basic principle for the operation of a thermally stimulated shape memory polymer (SMP) is a drastic change in elastic modulus above the glass transition temperature (Tg). This change from glassy modulus to rubbery modulus allows the material to be deformed above the Tg and retain the deformed shape when cooled below the Tg. The material will recover its original shape when heated above the Tg again. However, thermal activation is not the only possibility for a polymer to exhibit this shape memory effect or change of modulus. This paper discusses results of an alternative approach to SMP activation.It is well known that the Tg of a thermosetting polymer is proportional to its crosslinking density. It is possible for the crosslinking density of a room temperature elastomer to be modified through photo-crosslinking special photo-reactive monomer groups incorporated into the material system in order to increase its Tg. Correspondingly, the modulus will be increased from the rubbery state to the glassy state. As a result, the material is transformed from an elastomer to a rigid glassy photoset, depending on the crosslinking density achieved during exposure to the proper wavelength of light. This crosslinking process is reversible by irradiation with a different wavelength, thus making it possible to produce light-activated SMP materials that could be deformed at room temperature, held in deformed shape by photo-irradiation using one wavelength, and recovered to the original shape by irradiation with a different wavelength.In this work, monomers which contain photo-crosslinkable groups in addition to the primary polymerizable groups were synthesized. These monomers were formulated and cured with other monomers to form photo-responsive polymers. The mechanical properties of these materials, the kinetics, and the reversibility of the photo-activated shape memory effect were studied to demonstrate the effectiveness of using photo-irradiation to effect change in modulus (and thus shape memory effect).

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