Showing papers on "Smart material published in 2014"
TL;DR: The ability to use light to initiate physicochemical changes in polymers represents one of the most powerful and rapidly evolving approaches as discussed by the authors, which has the unique capacity for enabling 4D manipulation of each of those processes.
264 citations
TL;DR: The shape memory polymers (SMPs) as mentioned in this paper can be trapped in a thermodynamically-unfavorable shape, then triggered by an external stimulus to return to their original shape.
165 citations
TL;DR: In this paper, a shape memory polymer auxetic hexachiral structure is tailored to provide a tunable stiffness response in its fully deployed state by varying the angle of inter-hub connections, and yet is still able to undergo thermally stimulated deployment.
Abstract: Planar auxetic structures have the potential to impact on a wide range of applications from deployable and morphing structures to space-filling composite and medical treatments. The ability to fabricate auxetics from smart materials greatly enhances this facility by building in controllable actuation and deployment. A smart auxetic device can be compressed and fixed into a storage state. When deployment is required the device can be appropriately stimulated and the stored elastic energy is released, resulting in a marked structural expansion. Instead of using a conventional external actuator to drive deployment the material is made to undergo phase transition where one stimulus (e.g. heat) initiates a mechanical response. Here we show how smart material auxetics can be realized using a thermally responsive shape memory polymer composites. We show how a shape memory polymer auxetic hexachiral structure can be tailored to provide a tunable stiffness response in its fully deployed state by varying the angle of inter-hub connections, and yet is still able to undergo thermally stimulated deployment.
97 citations
TL;DR: In this article, the authors provide an introduction to smart materials, with an emphasis on their capabilities and applications, and provide an insight into the rapidly developing technology and applications of smart materials.
Abstract: Purpose – This paper aims to provide an introduction to smart materials, with an emphasis on their capabilities and applications. Design/methodology/approach – Following an introduction, this paper first considers what smart materials are and what they can do. It then discusses existing and emerging applications of shape changing, self-actuating, self-healing, self-diagnostic and self-sensing materials. Findings – Although difficult to define unambiguously, smart materials offer a range of unique characteristics and have been used in a multitude of products, ranging from household goods and novelty items to automotive components and medical devices. They are the topic of extensive research and all manner of new applications will emerge in the future, reflecting both technological developments and a growing awareness of their capabilities. Originality/value – This paper provides an insight into the rapidly developing technology and applications of smart materials.
88 citations
TL;DR: A comprehensive review on the different aspects of Ferrofluids research is presented in this paper, where the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long-range ordering.
Abstract: Ferrofluids (FFs) or magnetic nanofluids are incredible smart materials consisting of ultrafine magnetic nanoparticles suspended in a liquid carrier medium, which exhibit both fluidity and magnetic controllability. Studies involving the dynamics and physicochemical properties of these magnetic nanofluids are an interdisciplinary area of research attracting researchers from different fields of science and technology. Herein, a comprehensive Review on the different aspects of FF research is presented. First, the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long-range ordering. The Review also details the rheological and thermal properties, dynamic instabilities, phase behavior, and particle assemblies in FFs to form complex multipolar geometries, photonic nanostructures, labyrinth structures, thin films, and droplets. Many important characterization techniques for probing FF properties are also briefly discussed, and the numerous innovative applications and future prospects of FFs are outlined.
81 citations
TL;DR: This paper provides a pathway to low cost, passive, fully printable sensor nodes for realtime condition monitoring and their characteristics in the influence of various physical parameters have been analyzed.
Abstract: Smart materials for chipless RFID sensors have not been developed for the broadband/high speed wireless data communication yet. Their applications are confined to some dc and very high frequency physical sensors. In this paper, various smart materials for RF sensing applications and their characteristics in the influence of various physical parameters have been analyzed. The working principle of chipless RFID sensors along with their various design and experimental results as well as their potential application is also presented. This paper provides a pathway to low cost, passive, fully printable sensor nodes for realtime condition monitoring.
79 citations
TL;DR: In this paper, an approach to optimize concurrently the variables describing the wing external shape, the internal compliant structure, and the embedded actuators is presented, considering the activation of the smart materials.
Abstract: The design of morphing wings involves the disciplines of aerodynamics and structural mechanics; the aero-structural coupling is of chief importance in case smart materials are used as distributed actuators. Considering these specific requirements, this paper presents an approach to optimize concurrently the variables describing the wing external shape, the internal compliant structure, and the embedded actuators. An aeroelastic analysis tool is developed to simulate the response of distributed compliance three-dimensional wings, considering the activation of the smart materials. A method to formulate the optimization requirements based on the aircraft mission is presented, using the aerodynamic performance from the aeroelastic study in the optimization goal. To prove the validity and the computational feasibility of this methodology, a morphing wing for a 3-m-wingspan radio-controlled plane is optimized. A structural concept actuated by single crystal Macro Fiber Composites and dielectric elastomers is in...
76 citations
TL;DR: This review highlights the recent progress of the dynamic self-assembly of coordination polymers that result from the sophisticated molecular design, towards fabricating stimuli-responsive systems and bio-related materials.
Abstract: The construction of supramolecular polymers has been intensively pursued because the nanostructures formed through weak non-covalent interactions can be triggered by external stimuli leading to smart materials and sensors. Self-assemblies of coordination polymers consisting of metal ions and organic ligands in aqueous solution also provide particular contributions in this area. The main motivation for developing those coordination polymers originates from the value-added combination between metal ions and ligands. This review highlights the recent progress of the dynamic self-assembly of coordination polymers that result from the sophisticated molecular design, towards fabricating stimuli-responsive systems and bio-related materials. Dynamic structural changes and switchable physical properties triggered by various stimuli are summarized. Finally, the outlook for aqueous nanostructures originated from the dynamic self-assembly of coordination polymers is also presented.
65 citations
01 Jan 2014
TL;DR: In this article, the basic principles of the upper and lower critical temperature polymer phase transitions are discussed, followed by an overview and discussion of important aspects of various key types of temperature-responsive polymers.
Abstract: This chapter describes polymers that undergo a temperature-induced phase transition in aqueous solution providing an important basis for smart materials. Different types of temperature-responsive polymers, including shape-memory materials, liquid crystalline materials and responsive polymer solutions are briefly introduced. Subsequently this chapter will focus on thermoresponsive polymer solutions. At first, the basic principles of the upper and lower critical temperature polymer phase transitions will be discussed, followed by an overview and discussion of important aspects of various key types of such temperature-responsive polymers. Finally, selected potential applications of thermoresponsive polymer solutions will be described.
64 citations
TL;DR: In this paper, photoinduced cis-trans isomerization of azobenzene has been an inspiration to chemists to design smart materials that respond to light, and this chemistry has also made a mark in the emerging area of metal-organic materials.
Abstract: Photoinduced cis–trans isomerisation of azobenzene has been an inspiration to chemists to design smart materials that respond to light. Lately, this chemistry has also made a mark in the emerging area of metal–organic materials. If one can regulate the properties of porous hybrid materials with light, their scope of applications can be expanded. The field is shown to be promising and gradually progressing from nano to mesospace. However, one needs more in-depth research to deliver materials that are truly smart and practically viable.
64 citations
TL;DR: In this article, the shape memory deformation mechanism of SMP smart structures is analyzed using a rheological constitutive model, which is composed of a revised standard linear solid (SLS) element and a thermal expansion element.
Abstract: There are various applications for shape memory polymer (SMP) in the smart materials and structures field due to its large recoverable strain and controllable driving method. The mechanical shape memory deformation mechanism is so obscure that many samples and test schemes have to be tried in order to verify a final design proposal for a smart structure system. This paper proposes a simple and very useful method to unambiguously analyze the thermoviscoelastic shape memory behavior of SMP smart structures. First, experiments under different temperature and loading conditions are performed to characterize the large deformation and thermoviscoelastic behavior of epoxy-SMP. Then, a rheological constitutive model, which is composed of a revised standard linear solid (SLS) element and a thermal expansion element, is proposed for epoxy-SMP. The thermomechanical coupling effect and nonlinear viscous flowing rules are considered in the model. Then, the model is used to predict the measured rubbery and time-dependent response of the material, and different thermomechanical loading histories are adopted to verify the shape memory behavior of the model. The results of the calculation agree with experiments satisfactorily. The proposed shape memory model is practical for the design of SMP smart structures.
TL;DR: In this article, a family of 2D refined equivalent single layer models for multilayered and functionally graded smart magneto-electro-elastic plates is presented based on variable kinematics and quasi-static behavior for the electromagnetic fields.
Abstract: A family of 2 D refined equivalent single layer models for multilayered and functionally graded smart magneto–electro-elastic plates is presented They are based on variable kinematics and quasi-static behavior for the electromagnetic fields First, the electromagnetic state of the plate is determined by solving the strong form of the electromagnetic governing equations coupled with the corresponding interface continuity conditions and external boundary conditions The electromagnetic state is then condensed into the plate kinematics, whose governing equations can be written using the generalized principle of virtual displacements The procedure identifies an effective elastic plate kinematically equivalent to the original smart plate The effective plate is characterized by inertia, stiffness and loading properties which take the multifield coupling effects into account through their definitions, which involve the electromagnetic coefficients appearing in the smart materials constitutive law The proposed model extends the techniques and tools available for the assessment of the mechanical behavior of multilayered composite plates to smart laminates Additionally, finite elements for the proposed single layer models are formulated and validated against available benchmark 3D solutions
TL;DR: This review gives an overview of material properties, engineering issues and fabrication technologies of magnetic shape memory alloys (MSMAs), and novel MEMS-compatible technologies are being developed to enable their micromachining and integration.
Abstract: By introducing smart materials in micro systems technologies, novel smart microactuators and sensors are currently being developed, e.g., for mobile, wearable, and implantable MEMS (Micro-electro-mechanical-system) devices. Magnetic shape memory alloys (MSMAs) are a promising material system as they show multiple coupling effects as well as large, abrupt changes in their physical properties, e.g., of strain and magnetization, due to a first order phase transformation. For the development of MSMA microactuators, considerable efforts are undertaken to fabricate MSMA foils and films showing similar and just as strong effects compared to their bulk counterparts. Novel MEMS-compatible technologies are being developed to enable their micromachining and integration. This review gives an overview of material properties, engineering issues and fabrication technologies. Selected demonstrators are presented illustrating the wide application potential.
TL;DR: In this paper, a series of parametric studies using the 3D coupled field finite element method (FEM) on all properties of materials involved in the lead zirconate titanate (PZT) structure interaction of the EMI technique, to investigate their effect on the admittance signatures acquired.
Abstract: The application of smart materials in various fields of engineering has recently become increasingly popular. For instance, the high frequency based electromechanical impedance (EMI) technique employing smart piezoelectric materials is found to be versatile in structural health monitoring (SHM). Thus far, considerable efforts have been made to study and improve the technique. Various theoretical models of the EMI technique have been proposed in an attempt to better understand its behavior. So far, the three-dimensional (3D) coupled field finite element (FE) model has proved to be the most accurate. However, large discrepancies between the results of the FE model and experimental tests, especially in terms of the slope and magnitude of the admittance signatures, continue to exist and are yet to be resolved. This paper presents a series of parametric studies using the 3D coupled field finite element method (FEM) on all properties of materials involved in the lead zirconate titanate (PZT) structure interaction of the EMI technique, to investigate their effect on the admittance signatures acquired. FE model updating is then performed by adjusting the parameters to match the experimental results. One of the main reasons for the lower accuracy, especially in terms of magnitude and slope, of previous FE models is the difficulty in determining the damping related coefficients and the stiffness of the bonding layer. In this study, using the hysteretic damping model in place of Rayleigh damping, which is used by most researchers in this field, and updated bonding stiffness, an improved and more accurate FE model is achieved. The results of this paper are expected to be useful for future study of the subject area in terms of research and application, such as modeling, design and optimization.
TL;DR: Smart behaviour occurs when a material can sense some stimulus from its environment and react to it in a useful, reliable, reproducible, and usually reversible manner, and these properties have a beneficial application in various fields including dentistry.
Abstract: By definition and general agreement, smart materials are materials that have properties which may be altered in a controlled fashion by stimuli, such as stress, temperature, moisture, pH, and electric or magnetic fields. There are numerous types of smart materials, some of which are already common. Examples include piezoelectric materials, which produce a voltage when stress is applied or vice versa, shape memory alloys or shape memory polymers which are thermoresponsive, and pH sensitive polymers which swell or shrink as a response to change in pH. Thus, smart materials respond to stimuli by altering one or more of their properties. Smart behaviour occurs when a material can sense some stimulus from its environment and react to it in a useful, reliable, reproducible, and usually reversible manner. These properties have a beneficial application in various fields including dentistry. Shape memory alloys, zirconia, and smartseal are examples of materials exhibiting a smart behavior in dentistry. There is a strong trend in material science to develop and apply these intelligent materials. These materials would potentially allow new and groundbreaking dental therapies with a significantly enhanced clinical outcome of treatments.
TL;DR: In this article, the authors explore the characteristics of a concrete block as a communication medium with piezoelectric transducers and provide estimates and validate the concrete channel response, demonstrating a nearly twofold increase in channel capacity by utilizing multiple transceivers to form an MIMO system.
Abstract: In this paper, we explore the characteristics of a concrete block as a communication medium with piezoelectric transducers. Lead zirconate titanate (PZT) is a piezoceramic material used in smart materials intended for structural health monitoring (SHM). Additionally, a PZT based smart aggregate (SA) is capable of implementing stress wave communications which is utilized for investigating the properties of an SA based concrete channel. Our experiments characterize single-input single-output and multiple-input multiple-output (MIMO) concrete channels in order to determine the potential capacity limits of SAs for stress wave communication. We first provide estimates and validate the concrete channel response. Followed by a theoretical upper bound for data rate capacity of our two channels, demonstrating a near-twofold increase in channel capacity by utilizing multiple transceivers to form an MIMO system. Our channel modeling techniques and results are also helpful to researchers using SAs with regards to SHM, energy harvesting and stress wave communications.
TL;DR: In this paper, the main control techniques applied to suppress vibrations in civil structures using smart materials are reviewed, remarking on the advantages and disadvantages of smart actuators and control strategies tendencies in smart civil structures.
Abstract: Smart civil structures are capable of partially compensating the undesirable effects due to external perturbations; they sense and react to the environment in a predictable and desirable form through the integration of several elements, such as sensors, actuators, signal processors, and power sources, working with control strategies. This article will focus on reviewing the main control techniques applied to suppress vibrations in civil structures using smart materials, remarking on the advantages and disadvantages of smart actuators and control strategies tendencies in smart civil structures.
TL;DR: In this paper, the main draw-backs are the nozzle-clogging and single-jet spinneret,respectively, which is a real limitation in terms of usable polymers and for patterning active organics.
Abstract: lthough electrospinning (ES) allows the production ofunsurpassed nanoscale polymer fibers, the major draw-backs are the nozzle-clogging and single-jet spinneret,respectively. This is a real limitation in terms of usablepolymers and for patterning active organics. Nowadays themicro-engineering of smart materials could represent a newroute for many fields of technology ranging from theproduction of electronic and photonic devices
TL;DR: A smart device that can dive or surface in aqueous medium has been developed by combining a pH-responsive surface with acid-responsive magnesium, demonstrating that motional energy can be realized by consuming chemical energy of magnesium, thus producing electricity.
Abstract: A smart device that can dive or surface in aqueous medium has been developed by combining a pH-responsive surface with acid-responsive magnesium. The diving-surfacing cycles can be used to convert chemical energy into electricity. During the diving-surfacing motion, the smart device cuts magnetic flux lines and produces a current, demonstrating that motional energy can be realized by consuming chemical energy of magnesium, thus producing electricity.
TL;DR: This review will highlight current work in the area of aptamer-based smart materials and prospects for their future applications.
Abstract: “Smart” materials are an emerging category of multifunctional materials with physical or chemical properties that can be controllably altered in response to an external stimulus. By combining the standard properties of the advanced material with the unique ability to recognize and adapt in response to a change in their environment, these materials are finding applications in areas such as sensing and drug delivery. While the majority of these materials are responsive to physical or chemical changes, a particularly exciting area of research seeks to develop smart materials that are sensitive to specific molecular or biomolecular stimuli. These systems require the integration of a molecular recognition probe specific to the target molecule of interest. The ease of synthesis and labeling, low cost, and stability of DNA aptamers make them uniquely suited to effectively serve as molecular recognition probes in novel smart material systems. This review will highlight current work in the area of aptamer-based smart materials and prospects for their future applications.
TL;DR: In this paper, the authors investigated the mechanical and shape recovery properties of a styrene-based shape memory polymer composite reinforced by cup-stacked carbon nanotubes and showed that the composite can be used for shape memory.
Abstract: This study investigated the mechanical and shape recovery properties of a styrene-based shape memory polymer composite reinforced by cup-stacked carbon nanotubes. Due to their unique morphology, cu...
TL;DR: In this paper, an embedded sensing technique using a glass-coated ferromagnetic microwire with a specific magnetic anisotropy has been proposed, where the microwire impedance acts as the controlled parameter which is monitored for a weak alternating current (AC) in the MHz range.
Abstract: Considerable efforts have been made to develop testing non-destructive methods for polymer composite materials. We would like to introduce researchers in the field of smart materials to a new method of monitoring internal stresses. The method can be classified as an embedded sensing technique, where the sensing element is a glass-coated ferromagnetic microwire with a specific magnetic anisotropy. With a diameter 10–100 μm, the microwire impedance acts as the controlled parameter which is monitored for a weak alternating current (AC) in the MHz range. The microwire impedance becomes stress sensitive in the presence of a weak constant axial bias magnetic field. This external parameter allows the impedance stress sensitivity to be easily tuned. In addition, a local bias field may also allow the reconstruction of stress profile when it is scanned along the microwire. The experimental results are analysed using simple magnetostatic and impedance models.
TL;DR: In this article, the use of shape-memory alloys (SMAs) for vibration control, shape control, position control, and adaptive stiffening is reviewed in the context of composite materials.
Abstract: Composite materials have increasingly been used in construction and in the aerospace and automotive industries because they are lightweight, strong and corrosion resistant, and because their anisotropic properties can be controlled; maintenance costs are also low. However, there is a growing demand for improved composite materials which have 'smart' capabilities, that is, they are able to sense, actuate and respond to the surrounding environment. Shape-memory alloys (SMAs) possess sensing and actuating functions. Embedding SMAs into composite materials can create smart or intelligent composites. Amongst the commercially available SMAs, NiTi alloys - in the form of wires, ribbons or particles - are the most widely used because of their excellent mechanical properties and shape-memory performance. These materials have found application in broad fields of engineering and science as a result of their superior thermomechanical properties. Here we review the use of NiTi SMAs in applications such as vibration control, shape control, position control and adaptive stiffening.
TL;DR: In this article, a light-controllable polymeric material is presented, in which exposure to light couples with a change in magnetic properties, allowing light signal conversion into nonvolatile magnetic memory.
Abstract: Remotely controlled actuation with wireless sensorial feed-back is desirable for smart materials to obtain fully computer-controlled actuators. A light-controllable polymeric material is presented, in which exposure to light couples with a change in magnetic properties, allowing light signal conversion into non-volatile magnetic memory. The same material can serve, additionally, both as actuator and transducer, and allows the monitoring of its two-way elastic shape-changes by magnetic read-out. In order to tune the macroscopic magnetic properties of the material, both the reorientation of i) shape anisotropic ferrimagnetic nano-spindles and ii) a mechanically and magnetically coupled liquid-crystalline elastomer (LCE) matrix are controlled. These materials are envisioned to have great potential for the development of innovative functional objects, for example, computer-controlled smart clothing, sensors, signal encoding, micro-valves, and robotic devices.
TL;DR: In this paper, a fully geometrically nonlinear finite element (FE) model is developed using large rotation shell theory for static analysis of composite and piezoelectric laminated thin-walled structures.
Abstract: A fully geometrically nonlinear finite element (FE) model is developed using large rotation shell theory for static analysis of composite and piezoelectric laminated thin-walled structures. The proposed large rotation theory is based on the first-order shear deformation (FOSD) hypothesis. It has six independent kinematic parameters which are expressed by five mechanical nodal degrees of freedom (DOFs). Linear electro-mechanically coupled constitutive equations with a constant electric field distribution through the thickness of each smart material layer are considered. Eight-node quadrilateral plate/shell elements with five mechanical DOFs per node and one electrical DOF per smart material layer are employed in the FE modeling. The present large rotation FE model is implemented into static analysis of both composite and piezoelectric laminated plates and shells. The equilibrium equation is solved by Newton–Raphson algorithm with system matrices updated in every iteration. The results are compared with those presented in the literature and others calculated by various simplified nonlinear shell theories. They indicate that large rotation theory has to be considered for the calculation of displacements and sensor output voltages of smart structures undergoing large deflections, since other simplified nonlinear theories fail to predict the static response precisely in many cases.
TL;DR: Thiol-isocyanate-methacrylate two-stage reactive network polymers were developed and used for fabrication of well-defined surface patterns as well as functional geometric shapes to demonstrate a new methodology for processing of "smart materials".
Abstract: Thiol-isocyanate-methacrylate two-stage reactive network polymers were developed and used for fabrication of well-defined surface patterns as well as functional geometric shapes to demonstrate a new methodology for processing of “smart materials”. The dynamic stage I networks were synthesized in base-catalyzed thiol-isocyanate cross-linking reactions to yield tough, glassy materials at ambient conditions. Methacrylate-rich stage I networks, incorporating photoinitiator and photoabsorber, were irradiated with UV light to generate stage II networks with intricate property gradients. Upon directional straining and subsequent temperature-dependent stress relief of the predefined gradient regions, the desired surface or bulk geometric transformations were achieved. Depending on the gradient extent in conjunction with photoorthogonal initiators, the introduced deformations were shown to be easily erasable by heat or permanently fixable by bulk polymerization.
TL;DR: In this paper, a method for size-triggered microdroplet target transport, achieved on gradient-step spindle-knot fibers (GSFs), is presented.
Abstract: We present a unique method for size-triggered microdroplet target transport, achieved on gradient-step spindle-knot fibers (GSFs). GSFs are controllably fabricated by developing a velocity-change coating method, the gradient features of which can have uni-directional, middle or two-side symmetric spindle-knot modes to modulate directional droplet target transport. This finding offers an insight into how to effectively control the direction of liquid self-transport for water collection, and may also be extended to smart materials which contribute to fluid control.
TL;DR: This review aims to bring together the most recent advances in smart nanomaterials, made to understand the surrounding environment and act accordingly by either protecting the drug in hostile conditions or releasing the "payload" at the intended intracellular target site.
Abstract: Nanotechnology has become important in various disciplines of technology and science. It has proven to be a potential candidate for various applications ranging from biosensors to the delivery of genes and therapeutic agents to tissue engineering. Scaffolds for every application can be tailor made to have the appropriate physicochemical properties that will influence the in vivo system in the desired way. For highly sensitive and precise detection of specific signals or pathogenic markers, or for sensing the levels of particular analytes, fabricating target-specific nanomaterials can be very useful. Multi-functional nano-devices can be fabricated using different approaches to achieve multi-directional patterning in a scaffold with the ability to alter topographical cues at scale of less than or equal to 100 nm. Smart nanomaterials are made to understand the surrounding environment and act accordingly by either protecting the drug in hostile conditions or releasing the "payload" at the intended intracellular target site. All of this is achieved by exploiting polymers for their functional groups or incorporating conducting materials into a natural biopolymer to obtain a "smart material" that can be used for detection of circulating tumor cells, detection of differences in the body analytes, or repair of damaged tissue by acting as a cell culture scaffold. Nanotechnology has changed the nature of diagnosis and treatment in the biomedical field, and this review aims to bring together the most recent advances in smart nanomaterials.
TL;DR: In this article, the authors theoretically model and experimentally investigate the electrode electrical properties and the mechano-electrical properties of the ionic polymer-metal composite (IPMC) sensor.
Abstract: In this study, we theoretically model and experimentally investigate the electrode electrical properties and the mechano-electrical properties of the ionic polymer-metal composite (IPMC) sensor. A physics-based model of the electrode was developed. In addition, based on the Poisson-Nernst-Planck system of equations, the current in the polymer membrane was modeled. By combining the physics of the polymer membrane and the electrode, the model of the surface electrical potential of the IPMC sensor was proposed. Experiments were conducted to test the electrical characteristics of the electrode and validate the model. The results demonstrate that the model can well describe the resistance, capacitance, and surface electrical potential of the IPMC electrode under external oscillation. Based on the model, a parametric study was done to investigate the impact of the parameters on the IPMC electrode properties. The results show that by changing the parameters of the electrode, such as the particle diameter, the electrode thickness, and microstructure, the electrical properties of the electrode can be changed accordingly. The current method of examining the electrode properties may also be applied to the study of electrodes for other smart materials.
TL;DR: It is shown that the disk-like aggregates can be orientated in magnetic fields, and such orientation can be preserved after embedding into gelatin, and the resulting gel cubes show an anisotropic transfer for electromagnetic waves.
Abstract: Mesostructures responding to external triggers such as temperature, pH, or magnetic field have the potential to be used as self-acting sensors, detectors, or switches. Key features are a strong and well-defined response to the external trigger. Here, we present magnetic alignable bicelles embedded into a gelatin matrix generating magnetically switchable structures, which can reversibly be locked and unlocked by adjusting the temperature. We show that the disk-like aggregates can be orientated in magnetic fields, and such orientation can be preserved after embedding into gelatin. The resulting gel cubes show an anisotropic transfer for electromagnetic waves, i.e., a different spatial birefringence. Cycling through the melting point of gelatin sets the structure back to its isotropic state providing a read-out of the thermal history. Stacking of the bicelles induced by the gelatin promotes magnetic aligning, as an increased aggregation number in the stacks increases the magnetic orientation energy.