Submitted Successfully!
To reward your contribution, here is a gift for you: A free trial for our video production service.
Thank you for your contribution! You can also upload a video entry or images related to this topic.
Version Summary Created by Modification Content Size Created at Operation
1
Sepideh Ghodrat
 + 4582 word(s) 4582 2021-09-19 15:06:45 |
2 format correct
Conner Chen
Meta information modification 4582 2021-10-08 08:45:46 | |
3 The format is correct
Lindsay Dong
Meta information modification 4582 2021-10-09 11:36:53 |

Video Upload Options

Do you have a full video?
Send video materials Upload full video

Confirm

Are you sure to Delete?
Yes No
Cite
If you have any further questions, please contact Encyclopedia Editorial Office.
Ghodrat, S. MSMPs and MSMs. Encyclopedia. Available online: https://encyclopedia.pub/entry/14672 (accessed on 27 July 2024).
Ghodrat S. MSMPs and MSMs. Encyclopedia. Available at: https://encyclopedia.pub/entry/14672. Accessed July 27, 2024.
Ghodrat, Sepideh. "MSMPs and MSMs" Encyclopedia, https://encyclopedia.pub/entry/14672 (accessed July 27, 2024).
Ghodrat, S. (2021, September 28). MSMPs and MSMs. In Encyclopedia. https://encyclopedia.pub/entry/14672
Ghodrat, Sepideh. "MSMPs and MSMs." Encyclopedia. Web. 28 September, 2021.
MSMPs and MSMs
Edit
This entry is adapted from the peer-reviewed paper 10.3390/magnetochemistry7090123

Magnetic shape memory polymers (MSMPs) belong to the group of shape memory materials, a group that can change their shape back to their “remembered” shape when they are exposed to a stimulus. MSMPs are essentially shape memory polymers whose shape memory effect is stimulated by heat. In the case of the MSMPs, magnetic particles are incorporated in the shape memory polymer. When the material is placed in an external alternating magnetic field, the magnetic particles heat up due to induction heating. The heated particles heat the shape memory polymer from the inside and when the activation temperature is reached, the shape memory effect is activated. Magnetic soft materials (MSMs) exist out of an elastomer with incorporated magnetic particles. The magnetic fields of these magnetic particles are set in specific magnetization patterns inside the elastomer during the fabrication process. When the magnetic soft material is placed inside an external static magnetic field, the magnetic fields of the magnetic particles align with the external magnetic field. This creates micro torques in the elastomer and pulls the elastomer matrix in a programmed shape.

magnetic shape memory polymers (MSMP) magnetic soft materials (MSMs) shape recovery

1. MSMP Filled with Magnetic Fillers

1.1. MSMPs Filled with Fe3O4

Schmidt [1] tried to make remotely controllable shape memory polymers. She made a shape memory polymer with incorporated magnetic particles (Fe3O4). These magnetic particles are used to heat the shape memory polymer by induction heating the particles by an AC field. The Massart and Cabuil method was employed for the experimental part [2]. Magnetite nanoparticles between 2 and 12 wt% were used for magnetic heating. She succeeded in remotely activating the shape memory effect with the magnetic particles (see Figure 1), while also maintaining basic thermal and mechanical properties of the polymer matrix.
Magnetochemistry 07 00123 g001 550
Figure 1. Deformed magnetic shape memory polymer, induction heated magnetic shape memory polymer in the process of recovering its memorized shape, recovered memorized shape [1].
Mohr, et al. [3] also performed research to remotely activate the shape memory effect of a shape memory polymer. Shape changing from a temporary shape (corkscrew like spiral) to a permanent shape (plane stripe) happened within 22 s (see Figure 2). In this study, they made two types of MSMPs. One had a base of polyetheruerthane (TFX) and the other a biodegradable multi block copolymer (PDC). For the magnetic micro particles, Fe3O4 was used. They found that the 88 °C maximum temperatures reached by induction heating were dependent on the added magnetic particles and the shape made with the MSMP. All experiments were done with a constant cooling and heating rate of 10 K/min. Moreover, the shape recovery capabilities of induction-heated MSMPs with an AC magnetic field seemed very similar to that for conventional shape memory polymers activated by an environmental heat change, which makes them a promising candidate for smart implants and controlled medical instruments.
Magnetochemistry 07 00123 g002 550
Figure 2. Shape memory effect through induction heating [3].
Instead of using randomly distributed magnetic micron particles, Leng, et al. [4] fabricated a MSMP with the magnetic powder laying in chains by applying a 0.03 T field by an AC magnetic field. They confirmed the formation of clear chain structure in chained samples. These chains increase the electrical conductivity in the shape memory polymer. Due to this, a lower electric voltage is needed to heat the MSMP and activate the shape change. Furthermore, they reported that alignment of magnetic particle chains significantly improves the mechanical properties of the SMP.
In addition, Yakacki, et al. [5] did further research on the influence of the percentage of magnetic particles (Fe3O4) incorporated in the polymer matrix. There is a direct influence of the percentage of the added particles on the induction heating rate of the material by an AC magnetic field. The polymer did not influence the heating of the particles. Higher percentages of the magnetic powder also lowered the glass temperature of the material. Materials with a lower percentage of magnetic particles had more crosslinks and therefore had higher glass temperature. Finally, when a large percentage of magnetic particles was added to the polymer matrix, the material had some strains that could not be repaired and the material was more brittle.
Razzaq et al. [6] also investigated the thermal and electrical performance of a MSMP with various wt% of Fe3O4 particles. They found that the thermal conductivity of the polymer matrix increased with the increase of magnetic particle fraction. The thermal conductivity improved from 0.19 to 0.60 W/mK with the increase of magnetite volume fraction but the polymer specific electrical resistivity showed a reversed trend. The changes of resistivity could be due to a conversion of the morphology of the polymer matrix which leads to a faster separation of magnetic particles.
Yu, et al. [7] developed a MSMP made from poly(ε-caprolactone) (c-PCL) with incorporated Fe3O4 nanoparticles (5–25 wt%). One part of their study consisted of researching the results of crosslinking the polymer. These crosslinks increased the shape recovery of the polymer up to 70%. The MSMP was also activated by both hot water and by an alternating magnetic field. Figure 3 gives an intuitive contrast of the shape-recovery process in both an AC magnetic field and hot water. They observed that both magnetic nanoparticles and hot water stimulated the shape recovery of the helicoidal specimens. However, shape recovery time was significantly different. Thus, this revealed that the reactivity of c-PCL/Fe3O4 was better in hot water compared to an AC magnetic field. They believed that the faster recovery time was due to higher thermal transfer and lower heat loss in hot water.
Magnetochemistry 07 00123 g003 550
Figure 3. (above, (a)) The shape memory effect activated in a heated environment (hot water), (below (b)) the shape memory effect remotely activated by an alternating magnetic fields [7].
Weigel, et al. [8] studied the effect of different parameters on the shape memory effect of MSMPs initiated by induction heating through an AC magnetic field. Parameters that were studied were the properties of the magnetic particles, what they were made of, how they were distributed in the polymer matrix, the heat transport conditions, and the surface to volume ratio. The investigated materials were polyetherurethane and a biodegradable multiblock copolymer (PDC) with integrated Fe3O4 particles. They found that with the addition of 10 wt% of magnetic particles in the polymer, the shape memory improved and the mechanical properties of the polymer were not changed.
Instead of making a one-way shape recovery MSMP, Kumar, et al. [9] made a MSMP that was triple-shape and could memorize two shapes; the shape memory effect was activated by an AC magnetic field. The magnetic triple-shape polymer was made of poly(3-caprolactone) (PCL) and poly(cyclohexyl methacrylate) (PCHMA) with incorporated Fe3O4 particles. The best triple-shape memory effect was achieved by a composite with 40 wt% PCL.
Yang, et al. [10] made a MSMP out of a polynorbornene copolymer and magnetite (Fe3O4) with a size of 55 nm. The shape memory effect was activated at a temperature of 51 °C, by the induction heating of magnetite by an AC magnetic field. Through the addition of the magnetic particles, the shape recovery of the material declined. The recovery time for the polymer was 186 s. The added magnetic particles also increased the thermal conductivity of the polymer.
Cai, et al. [11] also made a MSMP out of poly(ε-caprolactone)-polyurethane with incorporated Fe3O4. The nanocomposites were made by in situ polymerization at a molar ratio of PCL:MDI:BDO (1:4:3) with various content of Fe3O4 nanoparticles. The magnetic particles were homogeneously distributed in the polymer matrix. The shape memory effect was tested both by the activation of hot water and by the induction heating of the magnetic particles by an AC magnetic field (see Figure 4). It was found that the shape recovery started around 40 °C. The best shape recovery was of 97%. Their experiments confirmed that the shape change was faster in hot water compared to the ones heated by magnetic fields. In addition, they reported that shape recovery rate decreased with the more magnetic particles whereas shape recovery time increased.
Magnetochemistry 07 00123 g004 550
Figure 4. (left) The shape recovery process in hot water, (right) the shape recovery process in an alternating magnetic field [11].
The development of models to further predict how the magnetic particles influence the shape change of the MSMPs was further studied by Yu, et al. [12]. They used a finite element model that was previously developed to model shape memory polymers. Parameters that they studied were particle size, particle volume fraction, particle heating temperature, and rate to magnetically induce shape recovery behavior. The overall outcome was that an increased volume percentage of the magnetic particles or the smaller the size of the particles increased the heating of the material which stimulated the shape memory effect. They also found that there was a limit to the added volume fraction of particles. When adding particles above this volume percentage, there was no increase in the heating rate of the material.
Liu, et al. [13] developed a dual-response shape memory polymer, which is the same as a MSMP. In this research, the carboxylic styrene butadiene rubber (XSBR)/ferriferrous oxide (Fe3O4)/zinc dimethacrylate (ZDMA) was synthesized and tested. The authors investigated how the shape memory effect of the polymer behaved through the two different types of actuation, a heated environment or by induction heating through an AC magnetic field of the magnetic particles (Fe3O4) (see Figure 5). The shape recovery ratio of both shape memory activation methods was 100% but with different response times. It is noticeable that the shape recovery rate under magnetic fields was lower at the initial stage and higher in the last phase. This might be due to the fact that heating by an AC magnetic field is a slow process in the early stage and fast in the end phase.
Magnetochemistry 07 00123 g005 550
Figure 5. (Left) shape memory activated by a heated environment, (right) shape memory activated by an AC magnetic field [13].
Zhang, Wang, Zheng, Liu and Leng [14] made a MSMP out of PLA with incorporated Fe3O4 particles, that is activated by an AC magnetic field. For this material, the shape memory behaviors were studied through a lens for biomedical applications. It was found that the developed bone support structure (see Figure 6) could very quickly return to its remembered shape, in a few seconds, and the surface temperature of the induction heated material was uniform and around 40 °C, which makes the material safe to use inside the human body. They reported that the shape recovery rate was about 96%. The bones could recover their initial shape within 100 s under a magnetic field. However, they confirmed that the shape recovery time in a hot water was much faster (about 10 s).
Magnetochemistry 07 00123 g006 550
Figure 6. The shape recovery of a printed structure (above (a1–a4)), the simulation of the shape recovery of a bone support structure in a bone (below, (b1–b4)) [14].
Zhao, et al. [15] also studied bone tissue scaffolds made out of PLA with incorporated Fe3O4 particles that were activated by an AC magnetic field. They mixed 20 wt% Fe3O4 with PLA. One of the noticed advantages of MSMPs is that in the context of biomedical design, these structures can be implemented in the body with minimally invasive surgery. Furthermore, this study found that the mechanical structure of the scaffolds was stable and could improve the attachment.

1.2. MSMP Filled with NdFeB

Golbang and Kokabi [16] fabricated a MSMP made out of polyethylene with incorporated NdFeB particles (5, 15, 40 wt%) and 2 wt% organoclay (cloisite 15A) that was activated by an AC magnetic field. The effect of different weight percentages of added NdFeB particles was studied. It was found that the highest generated heat by inductive heating was reliant on the magnetic particles. The sample that had a full shape recovery had 15 wt% of NdFeB particles.

1.3. MSMP Filled with Carbonyl Iron

In the study by Hassan, et al. [17], a MSMP was made with the use of high projection stereolithography with embedded iron carbonyl particles (CIPs). They used three-dimensional printing technology for the fabrication of novel functionally graded MSMPs. They mixed benzyl methacrylate as the monomer with a cross linker, and used poly(ethylene glycol) dimethacrylate (PEGDMA) and phenyl-bis(2,4,6-trimethylbenzoyl)phosphine oxide as the crosslinker and photoiniator, respectively. Through the addition of the magnetic particles, they measured an increased thermal conductivity. Other tests they performed were thermo-mechanical and microstructural surface characterization. The outcome of these tests showed that MSMPs are good for remote controllability, an improvement in the thermal conductivity after embedding the CIPs and close interaction between the particles and the matrix. TGA and DMA results confirmed that the MSMPs have acceptable thermal stability and high mechanical strength.

1.4. MSMP Filled with Nickel Zinc Ferrite

With an increasing interest in making medical devices with shape memory polymers, Buckley, et al. [18] made a shape memory polymer with incorporated nickel zinc ferrite ferromagnetic particles that could be activated though induction heating by an alternating magnetic field. This interest in shape memory polymers for medical devices is because of the remote activation. The challenge for this type of device is to activate the shape memory effect safely and effectively in the body. They developed two in-house prototype devices to elaborate the impact of the added magnetic particles on SMP recovery. Their experiments highlighted that addition of 10 vol% of the magnetic particles made the material heat up uniformly and fast. This volume percentage did not compromise the shape recovery of the shape memory polymer.
In addition, Zhang, et al. [19] fabricated a MSMP with embedded nickel powder. The maximum volume percent of 20% was added to the base polymer. They observed that the homogeneous dispersion of powders had a noticeable effect on the thermal and mechanical abilities of the composite. The more nickel powder was added, the more the tensile strength of the polymer decreased. Two types of materials were made. One only had the added nickel particles. The other had the added nickel particles but it was treated before by a silane coupling agent. The samples with the silane coupling agent showed a better distribution of the particles throughout the material.

1.5. MSMP Filled with Ni-Mn-Ga

Aaltio, et al. [20] also made shape memory polymers with incorporated magnetic particles (Ni-Mn-Ga powder) laying in chains, like Leng, Lan, Liu, Du, Huang, Liu, Phee and Yuan [4]. They studied the damping capabilities of the material. Their developed material was tested on mechanical, structural, and magnetic properties and showed high passive damping for low frequencies. They also compared the damping of their developed material with the same polymeric matrix without magnetic particles and concluded that there was a significant difference between the two materials. They found an increment in the average grain size of the powder particles by the heat treatment. Their experiments confirmed that the magnetization improved more significantly parallel to the chained MSM particles rather than perpendicular to the chains.

1.6. MSMP Filled with Magnetite

Razzaq, et al. [21] studied the mechanical properties of shape memory polymers (polyurethane with 10–40 vol% magnetite). They mentioned the possibility of using AC induction heating. It was found that, with the inclusion of the magnetic particles, the shape memory polymer became more thermally stable but the glass temperature of the material decreased when more magnetite was added. Their report also concluded that the storage modulus of the material became higher when the amount of magnetite increased.
In a study by Puig, et al. [22], a MSMP was made out of magnetite particles that were coated with oleic acid and were embedded in an epoxy system inspired by diglycidylether of bisphenol A modified with oleic acid. The magnetic particles had a homogeneous distribution throughout the material. During the shape activation by an alternating magnetic field of the material, the surface became 25 °C warmer than when the material was not activated. This temperature was enough to activate the shape memory effect. They found the two-step reaction method to be essential to make a well dispersion of magnetics particles in the reactive solvent.

1.7. MSMP Filled with Iron

How the thermal and thermo-mechanical properties of the shape memory polymer were influenced by the addition of magnetic particles was also investigated by Cuevas, et al. [23]. They measured the shape recovery at 90%. Unlike other research, they found that the largest-sized sponged microparticles had a high capacity for the induction heating by an AC magnetic field of the material. Other outcomes of this research were that the stiffness of the shape memory polymer increased when adding more particles and that the material then also became more brittle.

1.8. MSMP Filled with Magnetite or Iron Oxide

Magnetite and iron oxide embedded in silica were compared as magnetic particles in a shape memory foam (Thermoset epoxy DP5.1) [24]. The shape memory effect was activated by the induction heating of the iron oxide by an AC magnetic field. Of these two particles, the iron oxide showed a better performance. It was found that adding a 10 wt% of magnetic particles to the foam did not influence the viscoelastic and thermo-mechanical properties of the material. In the performed experiments, the shapes were recovered within 10 to 20 s. Their results also confirmed that heat transfer between the filler nanoparticles and the bulk foam had a major role in increasing heating performance.

2. MSM

A predecessor of the magnetic soft material is presented in a study by Lagcore, et al. [25]. In that study, commercial epoxy resin bars were fabricated with embedded disc formed magnets (4 mm diameter and 90 µm thickness) (strontium ferrite powder). An 80% volume fraction of the hard ceramic ferrite powder was embedded in a commercial epoxy resin. The external magnetic field that was used to change the shape came from a planar coil. A finite element analysis and an analytical model were carried out, which showed good match results compared to the experimental tests.
Another example in which whole permanent magnets were added to a soft component can be seen in the study by Khoo and Liu [26], in which a micropump was developed from an elastomer with an incorporated magnet. By applying a magnetic field, the magnet moves and takes the elastomer with it creating a volume difference on either side of the elastomer. More than 80 mm displacement in the presence of the magnetics particles was reported. During the experiments, the external magnetic field was induced by a permanent disk-shaped NdFeB magnet that was moved near and away from the micro pump to vary the activation flux density.
Another example of hard magnets attached to each other with their magnetic fields pointed towards different directions can be seen in a study performed by [27]. They made different magnetic blocks, of which the magnetic axes (or directions) were orientated in different ways, by curing the materials under a static magnetic field of a permanent magnet. The external magnetic field in the experiment was homogeneous. By moving the permanent magnet, the external field changed its direction. Here, they have not yet made the transition to soft materials or attaching the two squares together by their sides instead of the wired connection.
Erb, et al. [28] also developed a type of magnetic self-shaped soft materials. In the study, they made a material that had a magnetization pattern existing out of two regions. They used a static permanent magnet during the curing process. They proposed a robust and universal technique to replicate this unusual shape-changing mechanism of original objects in an artificial bioinspired composite. They made it by first placing the uncured material in one mold and curing it under a permanent magnetic field. After that, more resin was added and cured under a permanent magnetic field in a different direction. Then, with prepared materials, they made bio-inspired structures. Hydrogel substrate containing aluminum oxide layers coated in Fe3O4 particles was added to a Teflon mold above which a permanent magnet was swiveled. The mold was cured with the magnetic field. To make a multi-layer structure, a second hydrogel substrate was merged to the mold and another orientation of magnetic field was imposed. The second layer of the solution was cured at a different orientation, after which the bilayer was extracted from the mold, Figure 7.
Magnetochemistry 07 00123 g007 550
Figure 7. The production process of the magnetic soft material [28].
Lum, et al. [29] were one of the first to develop a computer model to predict the shape memory behavior of MSMs. However, the model is not able to calculate all the shapes of the material over time and is restricted to only being able to define the shape with a 1D Fourier series. In addition, a fabrication process for the magnetic soft material was also presented, as shown in Figure 8. First, a beam of an elastomer (Ecoflex 10-00) with aluminum (non-magnetic; it had the same size as the NdFeB particles so that the elastomer had the same mechanical properties) particles was cast (Figure 8A,B). Depending on the preferred magnitude of shape change, a pater was laser cut out of this strip and filled with Ecofelx 10-00 with incorporated NdFeB (magnetic) particles (Figure 8C,D). After it was cured, the beam of magnetic soft material was folded in a jig (Figure 8E) and magnetized with a strong B field (~1 T) to get the right magnetization profile (Figure 8(Fi,Fii)). The external magnetic field was induced by an electromagnet.
Magnetochemistry 07 00123 g008 550
Figure 8. The manufacturing process of magnetic soft materials in the study by Lum, Ye, Dong, Marvi, Erin, Hu and Sitti [29]. (A) a negative mold; (B) the passive component; (C) laser cutting; (D) NdFeB and Elastomer poured and cured in the mold (E) the beam bent into the jig; (Fi) the beam is magnetized with a strong B field (~1 T); (Fii) the beam is removed from the jig.
Kim et al. [30] reported one of the first 3D printing magnetic responsive materials by incorporating magnetic microparticles (NdFeB) in a soft compound and printing non-uniform magnetization patterns. This was previously done by embedding whole magnets into a soft compound. Their printing method was based on direct ink writing. During the printing procedure, a static magnetic field was applied at the nozzle to reorient the particles along that field (see Figure 9a) generated by either a permanent magnet or an electromagnet. The magnetic shield between the electromagnet and the printed material weakened the magnetic field from the electromagnet, so that the printed magnetic patterns were not disturbed by it. This ink with its created magnetic field directions could then be used to print complex structures, Figure 9b, which enabled structures that were not possible to make before. For the shape change activation, a permanent magnet was used. The magnetic responsive soft material could react fast, untethered, and in a revered way. They found that with the increase of the applied field at the nozzle tip, the magnetic moment density of produced samples through nozzles improved. Furthermore, the effect of nozzles’ diameters on the magnetic moment density was investigated with their custom-made set-up.
Magnetochemistry 07 00123 g009 550
Figure 9. (a): The manufacturing process of magnetic soft material developed by Kim, Yuk, Zhao, Chester and Zhao [30] by which the magnetic particles oriented with the magnetic field that was applied at the nozzle. (b): Complex structures printed out of magnetic soft material [30].
Instead of using direct ink writing with a 3D printer to create non-uniform magnetization patters, Xu, et al. [31] developed another system based on ultraviolet lithography. Like the 3D printer set up by Kim, Yuk, Zhao, Chester and Zhao [30], this ultraviolet lithography setup is also able to make more complex non-uniform magnetization patterns. The permanent magnet under the plate on which the UV resin with incorporated magnetic particles (NdFeB) lays rotates and changes the orientation of the particles in the uncured resin. When the hall sensors detect that the particles are oriented in the right position, the part of the UV resin that should have this direction for the particles is cured by the exposure to precise target UV light. The design concept for a microgripper magnetically actuated with six-degree-of-freedom can be seen in Figure 10. The six degrees of freedom actuator refers to movement in three dimensions added to grasping, pitch, and yaw motion. The microgripper includes a base segment and multiple arms to encapsulate the cargo. Once the arms are wrinkled, the gripper could be considered as a rigid body and could locomote using the magnetic gradient pulling force or rolling motion (Figure 10A). The shifting steps of a green triangular prism-shaped with the designed microgripper is shown in Figure 10B.
Magnetochemistry 07 00123 g010 550
Figure 10. (A) Geometry and working mechanism of microgripper; (B) the cargo transportation task [31].
Roh, et al. [32] also made structures with MSMs. The 3D printed objects could float on water. In one of the important experiments in this study, structures were printed with varying stiffness. The relation between deformations and material stiffness was reported by Roh et al. This varying stiffness showed different deformations in the activated material through a static magnetic field from an electromagnet. In places where the material was softer, the deformation was bigger and larger, while in the stiffer regions, there was less deformation.
Another study that used varying stiffness in the elastomers was performed by Lantean, et al. [33]. They employed digital light processing to print programmable magnet polymeric materials with acceptable magnetic and mechanical properties. To test their material, a permanent NdFeB magnet was used and moved manually. They varied of the mechanical properties from soft to hard by combination of urethane-acrylate resins and butyl acrylate as a diluent medium. This made it possible to create straight surfaces in the cube. They also changed the magnetization strength of parts of the created objects by changing the weight percentage of the added magnetic particles Fe3O4 between 0% and 6%.
Moreover, soft magnetic objects were fabricated to mimic animal movements by Venkiteswaran et al. [34]. Isotropic powder was used, made from praseodymium-iron-boron (PrFeB) magnets and a silicone rubber polymer (1:1 mass ratio). The fabricated soft magnetic strips were made in different formations to show different types of motions that are possible to create. To create the magnetic soft material strips, a magnetic field of 1T of an electromagnet was used. The motion of the robots was activated by static magnetic fields induced by six electromagnets with a magnetic field strength from 10 to 35 mT. By switching different pairs of coils on and off, a rotating external magnetic field was created. The robots with a length of 4 mm had a speed between 0.15 and 0.37 mm/s. Their interesting outcomes showed that bio-mimetic characteristic patterns were followed by all the specimens. Reliable movement of the specimens, from one end of the workspace to the other, is other exciting achievement [34].
Wu, et al. [35] developed different NdFeB particles types of joints for MSM. These joints are symmetric joints and asymmetric joints. The difference between them is a gap between the same two magnetic poles that lay next to each other. The difference of the gap makes the shape transformations of the material, round or angular. Combinations of these types of joints can enable more different types of shape transformations (see Figure 11). The shape transformations were activated by a homogeneous magnetic field induced by electromagnetic coils. The field strengths and directions were changed to obtain the intended shape change during the study. The S−S−S combination (either a “W” or a “M” configuration) was achieved with folding under the changing magnetic fields with amplitude B of 4 mT (Figure 11a,d,e). For the S−A−S combination (Figure 11b,f,g), an “M” mode with B = 6 mT and an arc mode with B = −23 mT was obtained. These required differences in magnetic fields were due to the higher bending stiffness as compared to the folding stiffness. The same trend can be seen in the A-S-A combination (Figure 11c,h,i).
Magnetochemistry 07 00123 g011 550
Figure 11. A combination of symmetric (S) and asymmetric (A) joints [35]. (a) S−S−S (b) S−A−S (c) A−S−A. (d–i) Simulated deformations for the joint types in (a–c) with positive (d,f,h) and negative (e,g,i) magnetic field.

References

  1. Schmidt, A.M. Electromagnetic Activation of Shape Memory Polymer Networks Containing Magnetic Nanoparticles. Macromol. Rapid Commun. 2006, 27, 1168–1172.
  2. Massart, R.; Cabuil, V. Synthèse en milieu alcalin de magnétite colloïdale: Contrôle du rendement et de la taille des particules. J. De Chim. Phys. 1987, 84, 967–973.
  3. Mohr, R.; Kratz, K.; Weigel, T.; Lucka-Gabor, M.; Moneke, M.; Lendlein, A. Initiation of shape-memory effect by inductive heating of magnetic nanoparticles in thermoplastic polymers. Proc. Natl. Acad. Sci. USA 2006, 103, 3540–3545.
  4. Leng, J.S.; Lan, X.; Liu, Y.J.; Du, S.Y.; Huang, W.M.; Liu, N.; Phee, S.J.; Yuan, Q. Electrical conductivity of thermoresponsive shape-memory polymer with embedded micron sized Ni powder chains. Appl. Phys. Lett. 2008, 92, 014104.
  5. Yakacki, C.M.; Satakar, N.S.; Call, K.; Likos, R.; Hilt, J.Z. Shape-Memory Polymer Networks with Fe3O4 Nanoparticles for Remote Activation. J. Appl. Polym. Sci. 2009, 112, 3166–3176.
  6. Razzaq, M.Y.; Anhalt, M.; Frormann, L.; Weidenfeller, B. Thermal, electrical and magnetic studies of magnetite filled polyurethane shape memory polymers. Mater. Sci. Eng. 2007, 444, 227–235.
  7. Yu, X.; Zhou, S.; Zheng, X.; Guo, T.; Xiao, Y.; Song, B. A biodegradable shape-memory nanocomposite with excellent magnetism sensitivity. Nanotechnology 2009, 20, 235702.
  8. Weigel, T.; Mohr, R.; Lendlein, A. Investigation of parameters to achieve temperatures required to initiate the shape-memory effect of magnetic nanocomposites by inductive heating. Smart Mater. Struct. 2009, 18, 025011.
  9. Kumar, U.N.; Kratz, K.; Wagermaier, W.; Behl, M.; Lendlein, A. Non-contact actuation of triple-shape effect in multiphase polymer network nanocomposites in alternating magnetic field. J. Mater. Chem. 2010, 20, 3404–3415.
  10. Yang, D.; Huang, W.; He, X.; Xie, M. Electromagnetic activation of a shape memory copolymer matrix incorporating ferromagnetic nanoparticles. Polym. Int. 2012, 61, 38–42.
  11. Cai, Y.; Jian, J.-S.; Zheng, B.; Xie, M.-R. Synthesis and properties of magnetic sensitive shape memory Fe3O4/poly(ε-caprolactone)-polyurethane nanocomposites. J. Appl. Polym. Sci. 2012, 12, 49–56.
  12. Yu, K.; Westbrook, K.K.; Kao, P.H.; Leng, J.; Qi, H.J. Design considerations for shape memory polymer composites with magnetic particles. J. Compos. Mater. 2012, 47, 51–63.
  13. Liu, C.; Huang, J.; Yuan, D.; Chen, Y. Design of a High-Strength XSBR/Fe3O4/ZDMA Shape-Memory Composite with Dual Response. Ind. Eng. Chem. Res. 2018, 57, 14527–14534.
  14. Zhang, F.; Wang, L.; Zheng, Z.; Liu, Y.; Leng, J. Magnetic programming of 4D printed shape memory composite structures. Compos. Part A Appl. Sci. Manuf. 2019, 125.
  15. Zhao, W.; Huang, Z.; Liu, L.; Wang, W.; Leng, J.; Liu, Y. Porous bone tissue scaffold concepts based on shape memory PLA/Fe3O4. Compos. Sci. Technol. 2021, 203, 108563.
  16. Golbang, A.; Kokabi, M. Magnetic Field Actuation of Shape Memory Nanocomposites. Adv. Mater. Res. 2010, 123–125, 999–1002.
  17. Hassan, R.U.; Jo, S.; Seok, J. Fabrication of a functionally graded and magnetically responsive shape memory polymer using a 3D printing technique and its characterization. J. Appl. Polym. Sci. 2018, 135, 45997.
  18. Buckley, P.R.; McKinley, G.H.; Wilson, T.S.; Small, W.; Bennett, W.J.; Bearinger, J.P.; McElfresh, M.W.; Maitland, D.J. Inductively Heated Shape Memory Polymer for the Magnetic Actuation of Medical Devices. IEEE Trans. Biomed. Eng. 2006, 53, 2075–2083.
  19. Zhang, D.; Liu, Y.; Leng, J. Magnetic field activation of SMP networks containing micro nickel (Ni) powder. In Proceedings of the Second International Conference on Smart Materials and Nanotechnology in Engineering, Weihai, China, 8–11 July 2009.
  20. Aaltio, I.; Nilsén, F.; Lehtonen, J.; Ge, Y.; Spoljaric, S.; Seppälä, J.; Hannula, S.-P. Magnetic Shape Memory—Polymer Hybrids. Mater. Sci. Forum 2016, 879, 133–138.
  21. Razzaq, M.Y.; Anhalt, M.; Frormann, L.; Weidenfeller, B. Mechanical spectroscopy of magnetite filled polyurethane shape memory polymers. Mater. Sci. Eng. 2007, 471, 57–62.
  22. Puig, J.; Hoppe, C.E.; Fasce, L.A.; Pérez, C.J.; Piñeiro-Rendondo, Y.; Bañobre-López, M.; López-Quintela, M.A.; Rivas, J.; Williams, R.J.J. Superparamagnetic Nanocomposites Based on the Dispersion of Oleic Acid-Stabilized Magnetite Nanoparticles in a Diglycidylether of Bisphenol A-Based Epoxy Matrix: Magnetic Hyperthermia and Shape Memory. J. Phys. Chem. C 2012, 116, 13421–13428.
  23. Cuevas, J.M.; Alonso, J.; German, L.; Iturrondobeitia, M.; Laza, J.M.; Vilas, J.L.; León, L.M. Magneto-active shape memory composites by incorporating ferromagnetic microparticles in a thermo-responsive polyalkenamer. Smart Mater. Struct. 2009, 18, 075003.
  24. Vialle, G.; Prima, M.D.; Hocking, E.; Gall, K.; Garmestani, H.; Sanderson, T.; Arzberger, S.C. Remote activation of nanomagnetite reinforced shape memory polymer foam. Smart Mater. Struct. 2009, 18, 115014.
  25. Lagcore, L.K.; Brand, O.; Allen, M.G. Magnetic microactuators based on polymer magnets. J. Microelectromechanical Syst. 1999, 8, 2–9.
  26. Khoo, M.; Liu, C. Micro magnetic silicone elastomer membrane actuator. Sens. Actuators A 2001, 89, 259–266.
  27. Kim, J.; Chung, S.E.; Choi, S.-E.; Lee, H.; Kim, J.; Kwon, S. Programming magnetic anisotropy in polymeric microactuators. Nat. Mater. 2011, 10, 747–752.
  28. Erb, R.M.; Sander, J.S.; Grisch, R.; Studart, A.R. Self-shaping composites with programmable bioinspired microstructures. Nat. Commun. 2013, 4, 1712.
  29. Lum, G.Z.; Ye, Z.; Dong, X.; Marvi, H.; Erin, O.; Hu, W.; Sitti, M. Shape-programmable magnetic soft matter. Proc. Natl. Acad. Sci. USA 2016, 113, E6007–E6015.
  30. Kim, Y.; Yuk, H.; Zhao, R.; Chester, S.A.; Zhao, X. Printing ferromagnetic domains for untethered fast-transforming soft materials. Nature 2018, 558, 274–279.
  31. Xu, T.; Zhang, J.; Salehizadeh, M.; Onaizah, O.; Diller, E. Millimeter-scale flexible robots with programmable three-dimensional magnetization and motions. Sci. Robot. 2019, 4.
  32. Roh, S.; Okello, L.B.; Golbasi, N.; Hankwitz, J.P.; Liu, J.A.-C.; Tracy, J.B.; Velev, O.D. 3D-Printed Silicone Soft Architectures with Programmed Magneto-Capillary Reconfigurations. Adv. Mater. Technol. 2019, 4, 1800528.
  33. Lantean, S.; Barrera, C.; Pirri, C.F.; Tiberto, P.; Sangermano, M.; Roppolo, I.; Rizza, G. 3D Printing of Magnetoresponsive Polymeric Materials with Tunable Mechanical and Magnetic Properties by Digital Light Processing. Adv. Mater. Technol. 2019, 4, 1900505.
  34. Venkiteswaran, V.K.; Samaniego, L.F.P.; Sikorski, J.; Misra, S. Bio-Inspired Terrestrial Motion of Magnetic Soft Millirobots. IEEE Robot. Autom. Lett. 2019, 4, 1753–1759.
  35. Wu, S.; Ze, Q.; Zhang, R.; Hu, N.; Cheng, Y.; Yang, F.; Zhao, R. Symmetry-Breaking Actuation Mechanism for Soft Robotics and Active Metamaterials. Appl. Mater. Interfaces 2019, 11, 41649–44658.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license; additional terms may apply. By using this site, you agree to the Terms and Conditions and Privacy Policy.
Upload a video for this entry
Information
Subjects: Others
Contributor MDPI registered users' name will be linked to their SciProfiles pages. To register with us, please refer to https://encyclopedia.pub/register :
Sepideh Ghodrat
View Times: 661
Revisions: 3 times (View History)
Update Date: 09 Oct 2021
Table of Contents
    1000/1000
    Hot Most Recent
    Video Production Service
    Feedback