Electro-thermo-mechanical modeling of shape memory polymers filled with nano-carbon powder

2021 ◽  
pp. 1045389X2110643
Author(s):  
Jianping Gu ◽  
Shenglin Zhao ◽  
Hao Duan ◽  
Mengqi Wan ◽  
Huiyu Sun
Keyword(s):  
Shape Memory ◽  
Filler Content ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Electrical Current ◽  
Carbon Powder ◽  
Driving Mechanism ◽  
Recovery Ratio ◽  
Thermally Induced ◽  
Nano Carbon

Generally, adding the electroconductive fillers into the polymer matrix is a popular approach to endow the shape memory polymers (SMPs) with electroconductivity. Therefore, the shape memory effects (SMEs) of thermally induced SMPs can also be triggered by the electrical current. In essence, both the thermally activated and electrically activated SMEs share the same driving mechanism without considering the effect of heat conduction. In the paper, the constitutive model for the thermally induced SMPs filled with nano-carbon powder is briefly introduced. Then, a modified model is developed to characterize the effects of filler, deformation, and moisture on the electrical conductivity for the first time. After developing the correlation of electric field with Joule heat, the simulation is executed to display the free recovery of the shape memory polymer composites (SMPCs) with different filler content. It is found that the recovery ratio decreases with the increase of carbon powders for the SMPCs with filler content above the percolation threshold. Besides, a good recovery ratio can also be achieved through the application of a lower voltage.

scholarly journals Water Triggered Shape Memory Materials

2013 ◽  
Vol 3 (1) ◽  
pp. 49-50 ◽  
Author(s):  
Guoguang Niu
Keyword(s):  
Shape Memory ◽  
Shape Recovery ◽  
Shape Memory Polymers ◽  
Electrical Current ◽  
Light Illumination ◽  
Poly Ethylene Glycol ◽  
Thermally Induced ◽  
Permanent Shape ◽  
Poly Ethylene ◽  
Novel Strategy

The term "shape memory effect" refers to the ability of a material to be deformed and fixed into a temporary shape, and to recover its original, permanent shape upon an external stimulus (1). Shape memory polymers have attracted much interest because of their unique properties, and applied tremendously in medical area, such as biodegradable sutures, actuators, catheters and smart stents (2, 3). Shape memory usually is a thermally induced process, although it can be activated by light illumination, electrical current, magnetic, or electromagnetic field (4-6). During the process, the materials are heated directly or indirectly above their glass transition temperature (Tg) or the melting temperature (Tm) in order to recover the original shape. Non-thermally induced shape memory polymers eliminate the temperature constrains and enable the manipulation of the shape recovered under ambient temperature (7, 8). Herein, we report a novel strategy of water induced shape memory, in which the formation and dissolution of poly(ethylene glycol) (PEG) crystal is utilized for the fixation and recovery of temporary deformation of hydrophilic polymer. This water-induced shape recovery is less sensitive to temperature, of which 95% deformation is fixed in circumstance and over 75% recovery is reached even at 0 oC.

scholarly journals Harnessing reversible dry adhesion using shape memory polymer microparticles

RSC Advances ◽  
2021 ◽  
Vol 11 (32) ◽  
pp. 19616-19622
Author(s):  
Wenbing Li ◽  
Junhao Liu ◽  
Wanting Wei ◽  
Kun Qian
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Memory Effects ◽  
Reversible Adhesion ◽  
Dry Adhesion ◽  
Bonding Property ◽  
Shape Memory Effects ◽  
Polymer Microparticles

Shape memory polymers can provide excellent bonding property because of their shape memory effects. This paper proposes an adhesive unit that is capable of repeatable smart adhesion and exhibits reversible adhesion under heating.

scholarly journals Structural multi-colour invisible inks with submicron 4D printing of shape memory polymers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wang Zhang ◽  
Hao Wang ◽  
Hongtao Wang ◽  
John You En Chan ◽  
Hailong Liu ◽  
...  
Keyword(s):  
Shape Memory ◽  
Information Hiding ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Photonic Devices ◽  
Temperature Sensitive ◽  
4D Printing ◽  
Two Photon ◽  
Shape Memory Effects ◽  
Nanoscale Structure

AbstractFour-dimensional (4D) printing of shape memory polymer (SMP) imparts time responsive properties to 3D structures. Here, we explore 4D printing of a SMP in the submicron length scale, extending its applications to nanophononics. We report a new SMP photoresist based on Vero Clear achieving print features at a resolution of ~300 nm half pitch using two-photon polymerization lithography (TPL). Prints consisting of grids with size-tunable multi-colours enabled the study of shape memory effects to achieve large visual shifts through nanoscale structure deformation. As the nanostructures are flattened, the colours and printed information become invisible. Remarkably, the shape memory effect recovers the original surface morphology of the nanostructures along with its structural colour within seconds of heating above its glass transition temperature. The high-resolution printing and excellent reversibility in both microtopography and optical properties promises a platform for temperature-sensitive labels, information hiding for anti-counterfeiting, and tunable photonic devices.

Structural tuning of polycaprolactone based thermadapt shape memory polymer

2020 ◽  
Vol 11 (7) ◽  
pp. 1369-1374 ◽  
Author(s):  
Wusha Miao ◽  
Weike Zou ◽  
Yingwu Luo ◽  
Ning Zheng ◽  
Qiao Zhao ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Controlled Structures

Polycaprolactone based thermadapt shape memory polymers with precisely controlled structures allow tunable shape reconfigurability.

scholarly journals A Large-Deformation Theory for Thermally-Actuated Shape-Memory Polymers and its Application

2010 ◽  
Author(s):  
Shawn A. Chester ◽  
Vikas Srivastava ◽  
Claudio V. Di Leo ◽  
Lallit Anand
Keyword(s):  
Glass Transition ◽  
Shape Memory ◽  
Deformation Theory ◽  
Shape Recovery ◽  
Large Deformations ◽  
Shape Memory Polymers ◽  
The Body ◽  
Thermally Induced ◽  
Thermally Actuated ◽  
Common Shape

The most common shape-memory polymers are those in which the shape-recovery is thermally-induced. A body made from such a material may be subjected to large deformations at an elevated temperature above its glass transition temperature &Vthgr;g. Cooling the deformed body to a temperature below &Vthgr;g under active kinematical constraints fixes the deformed shape of the body. The original shape of the body may be recovered if the material is heated back to a temperature above &Vthgr;g without the kinematical constraints. This phenomenon is known as the shape-memory effect. If the shape recovery is partially constrained, the material exerts a recovery force and the phenomenon is known as constrained-recovery.

scholarly journals Shape-Memory Polymers for Biomedical Applications

2008 ◽  
Vol 54 ◽  
pp. 96-102 ◽  
Author(s):  
Andreas Lendlein ◽  
Marc Behl
Keyword(s):  
Shape Memory ◽  
Material Properties ◽  
Biomedical Applications ◽  
Traditional Approach ◽  
Shape Change ◽  
Shape Memory Polymers ◽  
Thermally Induced ◽  
Wide Range ◽  
Multifunctional Polymers ◽  
Suitable Process

Most polymers used in clinical applications today are materials that have been developed originally for application areas other than biomedicine. On the other side, different biomedical applications are demanding different combinations of material properties and functionalities. Compared to the intrinsic material properties, a functionality is not given by nature but result from the combination of the polymer architecture and a suitable process. Examples for functionalities that play a prominent role in the development of multifunctional polymers for medical applications are biofunctionality (e.g. cell or tissue specificity), degradability, or shape-memory functionality. In this sense, an important aim for developing multifunctional polymers is tailoring of biomaterials for specific biomedical applications. Here the traditional approach, which is designing a single new homo- or copolymer, reaches its limits. The strategy, that is applied here, is the development of polymer systems whose macroscopic properties can be tailored over a wide range by variation of molecular parameters. The Shape-memory capability of a material is its ability to trigger a predefined shape change by exposure to an external stimulus. A change in shape initiated by heat is called thermally-induced shape-memory effect. Thermally, light-, and magnetically induced shape-memory polymers will be presented, that were developed especially for minimally invasive surgery and other biomedical applications. Furthermore triple-shape polymers will be introduced, that have the capability to perform two subsequent shape changes. Thus enabling more complex movements of a polymeric material.

Shape Memory Behavior of Carbon Composites With Functional Interlayer

2018 ◽  
Author(s):  
L. Santo ◽  
L. Iorio ◽  
G. M. Tedde ◽  
F. Quadrini
Keyword(s):  
Carbon Fiber ◽  
Shape Memory ◽  
Polymer Composites ◽  
Polymer Matrix ◽  
Smart Materials ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Carbon Composites ◽  
Three Point Bending ◽  
Functional Behavior

Shape Memory Polymer Composites (SMPCs) are smart materials showing the structural properties of long-fiber polymer-matrix together with the functional behavior of shape memory polymers. In this study, SM carbon fiber reinforced (CFR) composites have been produced by using a SM interlayer between two CFR prepregs. Their SM properties have been evaluated in comparison with traditional structural CFR composites without the SM interlayer by using an especially designed test. Active and frozen forces are measured during a thermo-mechanical cycle in the three-point bending configuration. Experimental results show that SMPCs are able to fix a temporary deformed shape by freezing high stresses.

scholarly journals Shape-Memory Polymeric Artificial Muscles: Mechanisms, Applications and Challenges

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4246 ◽  
Author(s):  
Yujie Chen ◽  
Chi Chen ◽  
Hafeez Ur Rehman ◽  
Xu Zheng ◽  
Hua Li ◽  
...  
Keyword(s):  
Shape Memory ◽  
Smart Materials ◽  
Recent Progress ◽  
Shape Memory Polymer ◽  
Shape Memory Polymers ◽  
Artificial Muscles ◽  
Linkage Design ◽  
Wide Range ◽  
Liquid Crystal Elastomers ◽  
Made In

Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via Tm or Tg, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.

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