scholarly journals Ultrastretchable Elastic Shape Memory Fibers with Electrical Conductivity

2019 ◽  
Vol 6 (21) ◽  
pp. 1901579 ◽  
Author(s):  
Sungjune Park ◽  
Neil Baugh ◽  
Hardil K. Shah ◽  
Dishit P. Parekh ◽  
Ishan D. Joshipura ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Shape Memory ◽  
Shape Memory Fibers

Investigate of Electrical Conductivity of Shape-Memory Polymer Filled with Carbon Black

2008 ◽  
Vol 47-50 ◽  
pp. 714-717 ◽  
Author(s):  
Xin Lan ◽  
Jin Song Leng ◽  
Yan Ju Liu ◽  
Shan Yi Du
Keyword(s):  
Electrical Conductivity ◽  
Carbon Black ◽  
Shape Memory ◽  
Shape Recovery ◽  
Volume Fraction ◽  
Shape Memory Polymer ◽  
Recovery Process ◽  
Thermomechanical Properties ◽  
Electrically Conductive ◽  
New System

A new system of thermoset styrene-based shape-memory polymer (SMP) filled with carbon black (CB) is investigated. To realize the electroactive stimuli of SMP, the electrical conductivity of SMP filled with various amounts of CB is characterized. The percolation threshold of electrically conductive SMP filled with CB is about 3% (volume fraction of CB), which is much lower than many other electrically conductive polymers. When applying a voltage of 30V, the shape recovery process of SMP/CB(10 vol%) can be realized in about 100s. In addition, the thermomechanical properties are also characterized by differential scanning calorimetery (DSC).

Electrospinning of cationically polymerized epoxy/polycaprolactone blends to obtain shape memory fibers (SMF)

2017 ◽  
Vol 94 ◽  
pp. 376-383 ◽  
Author(s):  
Alvaro Iregui ◽  
Lourdes Irusta ◽  
Oihane Llorente ◽  
Loli Martin ◽  
Tamara Calvo-Correas ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Fibers

Mechanics of nickel–titanium shape memory alloys undergoing partially constrained recovery for self-healing materials

2018 ◽  
Vol 29 (15) ◽  
pp. 3025-3036 ◽  
Author(s):  
Nathan Salowitz ◽  
Ameralys Correa ◽  
Trishika Santebennur ◽  
Afsaneh Dorri Moghadam ◽  
Xiaojun Yan ◽  
...  
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Nickel Titanium ◽  
Self Healing ◽  
Bonding Agents ◽  
Compressive Loads ◽  
Martensitic State ◽  
Geometric Changes ◽  
Shape Memory Fibers

Engineered self-healing materials seek to create an innate ability for materials to restore mechanical strength after incurring damage, much like biological organisms. This technology will enable the design of structures that can withstand their everyday use without damage but also recover from damage due to an overload incident. One of the primary mechanisms for self-healing is the incorporation of shape memory fibers in a composite type structure. Upon activation, these shape memory fibers can restore geometric changes caused by damage and close fractures. To date, shape memory–based self-healing, without bonding agents, has been limited to geometric restoration without creating a capability to withstand externally applied tensile loads due to the way the shape memory material has been integrated into the composite. Some form of bonding has been necessary for self-healing materials to resist an externally applied load after healing. This article presents results of new study into using a form of constrained recovery of nickel–titanium shape memory alloys in self-healing materials to create residual compressive loads across fractures in the low temperature martensitic state. Analysis is presented relating internal loads in self-healing materials, potentially generated by shape memory alloys, to the capability to resist externally applied loads. Supporting properties were experimentally characterized in nickel–titanium shape memory alloy wires. Finally, self-healing samples were synthesized and tested demonstrating the ability to resist externally applies loads without bonding. This study provides a new useful characterization of nickel–titanium applicable to self-healing structures and opens the door to new forms of healing like incorporation of pressure-based bonding.

Electrical Conductivity of BioBased Shape Memory Polyurethane Filled with CNT

2016 ◽  
Vol 880 ◽  
pp. 69-72
Author(s):  
Ernie Suzana Ali ◽  
Azwani Sofia Ahmad Khiar ◽  
Syazana Ahmad Zubir ◽  
Zul Afiq Zaim Zulkeple
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Shape Memory ◽  
Palm Oil ◽  
Polymerization Process ◽  
Diphenylmethane Diisocyanate ◽  
Shape Memory Polyurethane ◽  
Step Polymerization

Biobased shape memory polyurethane filled with carbon nanotubes (CNT) were prepared using two step polymerization process. The bio based shape memory polyurethane (SMPU) were composed of polycaprolactonediol, polyol based on palm oil, 4, 4’-diphenylmethane diisocyanate and 1, 4-butanediol. In this paper, CNTs has been used as fillers to introduce the electrical conductivity in the SMPU. The bio-based shape memory polyurethane shows electrical conductivity with addition of 7 wt% CNT.

Mechanics of NiTi Reinforced Self-Healing Materials Producing Crack Closing Loads

2017 ◽  
Author(s):  
Nathan Salowitz ◽  
Ameralys Correa ◽  
Afsaneh Moghadam
Keyword(s):  
Shape Memory ◽  
Paradigm Shift ◽  
Fiber Composite ◽  
Self Healing ◽  
New Approach ◽  
The Matrix ◽  
Composite Form ◽  
External Loads ◽  
Shape Memory Fibers ◽  
Structural Matrix

Self-healing material structures with the inherent capability to mend damage will lead to a paradigm shift in design as fracture may no longer constitute a failure. Generally, there are two techniques of self-healing that operate at different scales, require different approaches and often are dealt with separately; geometric restoration and crack filling/bonding. Geometric restoration uses shape memory materials that can mechanically close fractures after they occur. Crack filling and bonding fills and chemically bonds fractured parts in place. Materials capable of recovering from complete fractures, that have propagated across the entire component, have typically taken a sparse fiber composite form with a structural matrix encapsulating shape memory fibers. This form of self-healing material has demonstrated the ability recover original bulk geometry. However, lacking bonding, the healed structures have not had the ability to resist subsequent externally applied loads without re-opening the crack. A new approach of pre-straining the shape memory fibers before curing them in a matrix in the pre-strained state is presented in this paper with basic theory and experimental results. Pre-straining the shape memory fibers before casting them in the matrix causes them to undergo constrained recovery upon activation. Thus, the samples create closing loads across the crack which are capable of withstanding external loads without re-opening.

Superelasticity of Cu–Ni–Al shape-memory fibers prepared by melt extraction technique

2016 ◽  
Vol 23 (8) ◽  
pp. 928-933 ◽  
Author(s):  
Dong-yue Li ◽  
Shu-ling Zhang ◽  
Wei-bing Liao ◽  
Gui-hong Geng ◽  
Yong Zhang
Keyword(s):  
Shape Memory ◽  
Extraction Technique ◽  
Melt Extraction ◽  
Shape Memory Fibers
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