Intelligent Material Systems Research Articles

Voices of Primary School Teachers About the Intelligent Material System Developed for Inclusive Education

This study investigates the primary school teachers’ perceptions towards the Intelligent Material System (IMS), which was developed to enhance the quality of inclusive environments and support the academic skills of students with Special Educational Needs (SEN). Within this scope, IMS training was conducted with 84 classroom teachers who worked at primary schools in İstanbul. Following the training, an open-ended questionnaire and two focus group interviews were used to collect data. The findings revealed that IMS has the potential to support the students with SEN academically, as it provides motivating and rich content, has a user-friendly interface and a desired level of accessibility despite the system’s limitations and the need for improvements noted by the participants.

ON-OFF Control of Marangoni Self-propulsion via A Supra-amphiphile Fuel and Switch.

Marangoni self-propulsion refers to motion of liquid or solid driven by a surface tension gradient, and has applications in soft robots/devices, cargo delivery, self-assembly etc. However, two problems remain to be addressed for motion control (e.g., ON-OFF) with conventional surfactants as Marangoni fuel: (1) limited motion lifetime due to saturated interfacial adsorption of surfactants; (2) in- situ motion stop is difficult once Marangoni flows are triggered. Instead of covalent surfactants, supra-amphiphiles with hydrophilic and hydrophobic parts linked noncovalently, hold promise to solve these problems owing to its dynamic and reversible surface activity responsively. Here, we propose a new concept of 'supra-amphiphile fuel and switch' based on the facile synthesis of disodium-4-azobenzene-amino-1,3-benzenedisulfonate (DABS) linked by a Schiff base, which has amphiphilicity for self-propulsion, hydrolyzes timely to avoid saturated adsorption, and provides pH-responsive control over ON-OFF motion. The self-propulsion lifetime is extended by 50-fold with DABS and motion control is achieved. The mechanism is revealed with coupled interface chemistry involving two competitive processes of interfacial adsorption and hydrolysis of DABS based on both experiments and simulation. The concept of 'supra-amphiphile fuel and switch' provides an active solution to prolong and control Marangoni self-propulsive devices for the advance of intelligent material systems.

ON–OFF Control of Marangoni Self‐propulsion via A Supra‐amphiphile Fuel and Switch

AbstractMarangoni self‐propulsion refers to motion of liquid or solid driven by a surface tension gradient, and has applications in soft robots/devices, cargo delivery, self‐assembly etc. However, two problems remain to be addressed for motion control (e.g., ON–OFF) with conventional surfactants as Marangoni fuel: (1) limited motion lifetime due to saturated interfacial adsorption of surfactants; (2) in‐ situ motion stop is difficult once Marangoni flows are triggered. Instead of covalent surfactants, supra‐amphiphiles with hydrophilic and hydrophobic parts linked noncovalently, hold promise to solve these problems owing to its dynamic and reversible surface activity responsively. Here, we propose a new concept of ‘supra‐amphiphile fuel and switch’ based on the facile synthesis of disodium‐4‐azobenzene‐amino‐1,3‐benzenedisulfonate (DABS) linked by a Schiff base, which has amphiphilicity for self‐propulsion, hydrolyzes timely to avoid saturated adsorption, and provides pH‐responsive control over ON‐OFF motion. The self‐propulsion lifetime is extended by 50‐fold with DABS and motion control is achieved. The mechanism is revealed with coupled interface chemistry involving two competitive processes of interfacial adsorption and hydrolysis of DABS based on both experiments and simulation. The concept of ‘supra‐amphiphile fuel and switch’ provides an active solution to prolong and control Marangoni self‐propulsive devices for the advance of intelligent material systems.

Intelligent electroactive material systems with self-adaptive mechanical memory and sequential logic

By synthesizing the requisite functionalities of intelligence in an integrated material system, it may become possible to animate otherwise inanimate matter. A significant challenge in this vision is to continually sense, process, and memorize information in a decentralized way. Here, we introduce an approach that enables all such functionalities in a soft mechanical material system. By integrating nonvolatile memory with continuous processing, we develop a sequential logic-based material design framework. Soft, conductive networks interconnect with embedded electroactive actuators to enable self-adaptive behavior that facilitates autonomous toggling and counting. The design principles are scaled in processing complexity and memory capacity to develop a model 8-bit mechanical material that can solve linear algebraic equations based on analog mechanical inputs. The resulting material system operates continually to monitor the current mechanical configuration and to autonomously search for solutions within a desired error. The methods created in this work are a foundation for future synthetic general intelligence that can empower materials to autonomously react to diverse stimuli in their environment.

Bio-Inspired Dynamically Morphing Microelectronics toward High-Density Energy Applications and Intelligent Biomedical Implants.

Choreographing the adaptive shapes of patterned surfaces to exhibit designable mechanical interactions with their environment remains an intricate challenge. Here, a novel category of strain-engineered dynamic-shape materials, empowering diverse multi-dimensional shape modulations that are combined to form fine-grained adaptive microarchitectures is introduced. Using micro-origami tessellation technology, heterogeneous materials are provided with strategic creases featuring stimuli-responsive micro-hinges that morph precisely upon chemical and electrical cues. Freestanding multifaceted foldable packages, auxetic mesosurfaces, and morphable cages are three of the forms demonstrated herein of these complex 4-dimensional (4D) metamaterials. These systems are integrated in dual proof-of-concept bioelectronic demonstrations: a soft foldable supercapacitor enhancing its power density (≈108mWcm-2), and a bio-adaptive device with a dynamic shape that may enable novel smart-implant technologies. This work demonstrates that intelligent material systems are now ready to support ultra-flexible 4D microelectronics, which can impart autonomy to devices culminating in the tangible realization of microelectronic morphogenesis.

Exploiting Molecular Orders at the Interface of Microdroplets for Intelligent Materials.

ConspectusThe intrinsic molecular order of liquid crystals (LCs) and liquid crystalline elastomers (LCEs) is the origin of their stimuli-responsive properties. The programmable responsiveness and functionality, such as shape morphing and color change under external stimuli, are the key features that attract interest in designing LC- and LCE-based intelligent material platforms. Methods such as mechanical stretching and shearing, surface alignment, and field-assisted alignment have been exploited to program the order of LC molecules for the desired responsiveness. However, the huge size mismatch between the nanometer-sized LC mesogens and the targeted macroscopic objects calls for questions about how to delicately control molecular order for desired performance. Microparticles that can be synthesized with intrinsic molecular order precisely controlled to micrometer size can be used as building blocks for bulk materials, thus offering opportunities to bridge the gap and transcend molecular orders across scales. By taking advantage of the interfacial anchoring effects, we can control and engineer the molecular orders inside the microdroplets, allowing for the realization of various responsive behaviors. Furthermore, designer LC microparticles with multiple responsiveness can be assembled and confined within a matrix, opening a new pathway to engineering LC-enabled intelligent materials.In this Account, we present our recent work on exploiting the molecular order inside microdroplets for the construction of intelligent materials. We briefly introduce the typical chemicals used in the synthesis and the methods developed to control LC molecular alignment within a microdroplets. We then present examples of microparticles synthesized from microdroplets that can transform into complex morphologies upon cooling from the isotropic to nematic phase or due to phase separation within the droplets coupled with the segregation of LC oligomers (LCOs) with polydisperse chain lengths. Furthermore, we show the synthesis of elliptical LCE microparticles and exploit their thermal and magnetic responsiveness to program shape-morphing behaviors and microarrays with switchable optical polarization. By mixing magnetic nanoparticles in cholesteric liquid crystals (CLCs) and silicone oils, we created Janus microparticles capable of color switching for camouflage and information encryption. Moreover, we can engineer complex molecular orders in LCE microparticles by mixing different surfactants, yielding microparticles of diverse anisotropic, temperature-responsive shapes after photopolymerization and extraction of the template LC molecules with different solvents. We conclude the Account with an outlook on the design of intelligent material systems via the design of unprecedented molecular ordering within the microparticles and their coupling with bulk materials.

Thermally trainable dual network hydrogels

Inspired by biological systems, trainable responsive materials have received burgeoning research interests for future adaptive and intelligent material systems. However, the trainable materials to date typically cannot perform active work, and the training allows only one direction of functionality change. Here, we demonstrate thermally trainable hydrogel systems consisting of two thermoresponsive polymers, where the volumetric response of the system upon phase transitions enhances or decreases through a training process above certain threshold temperature. Positive or negative training of the thermally induced deformations can be achieved, depending on the network design. Importantly, softening, stiffening, or toughening of the hydrogel can be achieved by the training process. We demonstrate trainable hydrogel actuators capable of performing increased active work or implementing an initially impossible task. The reported dual network hydrogels provide a new training strategy that can be leveraged for bio-inspired soft systems such as adaptive artificial muscles or soft robotics.

Investigation of the Mechanical Properties for Polymer Reinforced by Nanoparticles with Considering Viscoelasticity of the Matrix

Investigation of the Mechanical Properties for Polymer Reinforced by Nanoparticles with Considering Viscoelasticity of the Matrix

Dynamic magnetic field alignment and polarized emission of semiconductor nanoplatelets in a liquid crystal polymer

Reconfigurable arrays of 2D nanomaterials are essential for the realization of switchable and intelligent material systems. Using liquid crystals (LCs) as a medium represents a promising approach, in principle, to enable such control. In practice, however, this approach is hampered by the difficulty of achieving stable dispersions of nanomaterials. Here, we report on good dispersions of pristine CdSe nanoplatelets (NPLs) in LCs, and reversible, rapid control of their alignment and associated anisotropic photoluminescence, using a magnetic field. We reveal that dispersion stability is greatly enhanced using polymeric, rather than small molecule, LCs and is considerably greater in the smectic phases of the resulting systems relative to the nematic phases. Aligned composites exhibit highly polarized emission that is readily manipulated by field-realignment. Such dynamic alignment of optically-active 2D nanomaterials may enable the development of programmable materials for photonic applications and the methodology can guide designs for anisotropic nanomaterial composites for a broad set of related nanomaterials.

The maximum entropy method for data fusion and uncertainty quantification in multifunctional materials and structures

The quantification of uncertainty in intelligent material systems and structures requires methods to objectively compare complex models to measurements, where the majority of cases include multiple model outputs and quantities of interests given multiphysics coupling. This creates questions about constructing appropriate measures of uncertainty during fusion of data and comparisons between data and models. Novel materials with complex or poorly understood coupling can benefit from advanced statistical analysis to judge models in light of multiphysics data. Here, we apply the Maximum Entropy (ME) method to more complicated ferroelectric single crystals containing domain structures and soft electrostrictive membranes under both mechanical and electrical loading. Multiple quantities of interest are considered, which requires fusing heterogeneous information together when quantifying the uncertainty of lower fidelity models. We find that parameters, which were initially unidentifiable using a single quantity of interest, become identifiable using multiple quantities of interest. We also show that posterior densities may broaden or narrow when multiple data sets are fused together. This is likely due to conflict or agreement, respectively, between the different quantities of interest and the multiple model outputs. Such information is important to advance our predictions of intelligent materials and structures from multi-model inputs and heterogeneous data.

Gecko’s Feet-Inspired Self-Peeling Switchable Dry/Wet Adhesive

Dynamic switchable attachment/detachment behavior can be extensively observed in biological systems. Although wide interest has been focused on the fabrication of biomimetic synthetic switchable adhesives, designing intelligent adhesive material systems under both dry and wet conditions by following a peeling mechanism from mechanical deformation-induced adaptive evolution of the interface geometric contact state is still challenging. Herein, inspired by the rolling behavior of gecko’s feet, one kind of novel multilayered self-peeling switchable dry/wet adhesive (SPSA) is developed by integrating thermal-responsive hydrogel layers, gecko’s feet-inspired mushroom-structured arrays, and mussel-inspired copolymer adhesive coatings together. The SPSA shows thermal-responsive curving behavior along with switchable dry and underwater adhesion. Theoretical analysis is performed for explaining the dynamic curvature-induced switchable peeling mechanism. By integrating Fe3O4 nanoparticles into the SPSA, remote control over switchable adhesion can be achieved by applying near-infrared laser radiation. Considering potential applications, the SPSA can be used for successfully bonding/separating and capturing/releasing objects in air and in underwater environments. This research provides a new route for developing intelligent adhesion systems and mobile devices/robots.

Cylindrical Lithium-Ion Structural Batteries for Drones

The increasing use of battery-powered multirotor aircraft for industrial applications has allowed for advancements in a wide range of fields. These aircraft, however, have limited payloads and shorter endurance and range than fuel-powered conventional aircraft. To extend these key performance metrics, we have developed an optimized structural battery that uses commercially available battery cells as load bearing and power source elements for weight critical applications. Multifunctional lithium-based batteries have been previously proposed for the efficient use of space and mass in electric vehicles [1]. Lithium batteries offer an energy density high enough for most small multirotor flight applications [2], however these batteries often constitute a significant portion of the aircraft’s mass. This implementation is proposed to decrease the structural frame mass and thus increase multirotor performance characteristics such as payload capacity and flight time [3].In this work, structural lithium-ion batteries were integrated into the design of a commercial drone to improve hover time. Hover tests were first performed with the original lithium polymer batteries for comparison purposes. Battery voltage was measured every 2 minutes to monitor voltage decrease versus hover time. With no payload, the original hover time of the drone was 34 minutes. For payloads of 0.5, 1.0, and 1.5 kg, hover times decreased to 28.7, 22.7, and 19.1 minutes, respectively. Standard 18650 cylindrical battery cells (Panasonic NCR18650B) were then integrated into the carbon fiber arms of the drone, to replace the original lithium polymer batteries. This design modification reduced the weight of the drone from 1242 g to 848 g, while also improving the structural integrity of the carbon fiber arms. For both designs, the velocity of the drone was related to the impact force experienced in the case of a crash. The carbon fiber arms would fracture at 4 m/s when hollow, and 7 m/s when reinforced with lithium-ion batteries. Hover tests for this modified design are being performed currently, and times are expected to be on the order of 40% longer [4]. Ongoing efforts to investigate the relationship between the intensity of power usage and the angular inertia of the drone will help to characterize the optimal battery distribution.[1] Zhang YC, Ma J, Singh AK, et al. (2017) Multifunctional structural lithium-ion battery for electric vehicles. Journal of Intelligent Material Systems and Structures 28: 1603-1613.[2] Vikstrom, H.; Davidsson, S.; Hook, M., Lithium availability and future production outlooks. Applied Energy 2013, 110, 252-266.[3] Dughir, C.; Ieee, Power wire thickness influence on the multicopters flight time. 2016 12th Ieee International Symposium on Electronics and Telecommunications (Isetc'16) 2016, 239-242.[4] Hollinger AS, McAnallen DR, Brockett MT, DeLaney SC, Ma J, Rahn CD. Cylindrical lithium‐ion structural batteries for drones. International Journal of Energy Research. 2020; 44:560–566. Figure 1

Viewpoint: From Responsive to Adaptive and Interactive Materials and Materials Systems: A Roadmap.

Soft matter systems and materials are moving toward adaptive and interactive behavior, which holds outstanding promise to make the next generation of intelligent soft materials systems inspired from the dynamics and behavior of living systems. But what is an adaptive material? What is an interactive material? How should classical responsiveness or smart materials be delineated? At present, the literature lacks a comprehensive discussion on these topics, which is however of profound importance in order to identify landmark advances, keep a correct and noninflating terminology, and most importantly educate young scientists going into this direction. By comparing different levels of complex behavior in biological systems, this Viewpoint strives to give some definition of the various different materials systems characteristics. In particular, the importance of thinking in the direction of training and learning materials, and metabolic or behavioral materials is highlighted, as well as communication and information-processing systems. This Viewpoint aims to also serve as a switchboard to further connect the important fields of systems chemistry, synthetic biology, supramolecular chemistry and nano- and microfabrication/3D printing with advanced soft materials research. A convergence of these disciplines will be at the heart of empowering future adaptive and interactive materials systems with increasingly complex and emergent life-like behavior.

Cylindrical Lithium-Ion Structural Batteries for Multirotor Aircraft

The low cost, simplicity, and easy use of battery-powered multirotor aircraft has led to their adoption in commercial, industrial, agricultural, and military applications. These aircraft, however, have limited payloads and shorter endurance and range than fuel-powered conventional aircraft. While individual use cases of multirotor craft vary drastically, one of the most important variables in performance is aircraft mass. Lithium batteries offer an energy density high enough for most small multirotor flight applications, however these batteries often constitute a significant portion of the aircraft’s mass. The mass fraction of the multirotor that consists of batteries often inhibits flight characteristics similarly to an increased payload. This research proposes the use of lithium-ion batteries in a multifunctional configuration, providing both energy for flight operations and structural load-bearing capability. This implementation is proposed to decrease the structural frame mass and thus increase multirotor performance characteristics such as payload capacity and flight time. Multifunctional lithium-based batteries have been previously proposed for the efficient use of space and mass in electric vehicles [1]. Standard 18650 cylindrical battery cells (Panasonic NCR18650B) were used in this research as they are commercially available, have a circular cross-section, and have high energy density relative to prismatic or pouch lithium polymer cells often used in this application. The proposed configuration consists of a thin tube filled with 18650 cells to provide a multifunctional member with a high bending stiffness. The method of reinforcement is similar to that of the jellyroll electrodes placed within a thin cylindrical battery shell being substantially stronger than either alone [2]. The proposed configuration is compared with the non-reinforced tubing in three-point bending and shown to increase stiffness due to the load-bearing capabilities of the battery cells. The mechanical abuse tolerance of bare battery cells has been extensively tested, however, little data is available for reinforced cells or multifunctional cell configurations [3]. It has been noted that high strain rate and reduced state of charge negatively affect the integrity of Li-ion batteries [4]. Additionally, the mechanical properties of the jellyroll electrodes have been found to be anisotropic, contributing to non-uniform mechanical response of the cell as a whole [5]. In this study, testing was performed at a zero state of charge and a high strain rate to simulate the worst-case relative performance of the multifunctional members. In addition, multiple sizes of reinforced members were tested to investigate the scalability of the multifunctional configuration. The cylindrical lithium-ion structural battery presented here can provide both a power source and a load-bearing member for multirotor aircraft. Battery reinforcement is shown to provide up to 1100% stiffness and 750% yield strength improvements. Substitution of the proposed structural battery for aluminum tubes in a notional quadcopter design showed a 41% improvement in theoretical maximum hover time. This research motivates future multifunctional battery configurations with topologically optimized designs for various loading scenarios. [1] Zhang YC, Ma J, Singh AK, et al. (2017) Multifunctional structural lithium-ion battery for electric vehicles. Journal of Intelligent Material Systems and Structures 28: 1603-1613.[2] Zhang XW and Wierzbicki T. (2015) Characterization of plasticity and fracture of shell casing of lithium-ion cylindrical battery. Journal of Power Sources 280: 47-56.[3] Zhu J, Zhang XW, Sahraei E, et al. (2016) Deformation and failure mechanisms of 18650 battery cells under axial compression. Journal of Power Sources 336: 332-340.[4] Xu J, Liu BH, Wang XY, et al. (2016) Computational model of 18650 lithium-ion battery with coupled strain rate and SOC dependencies. Applied Energy 172: 180-189.[5] Sahraei E, Campbell J and Wierzbicki T. (2012a) Modeling and short circuit detection of 18650 Li-ion cells under mechanical abuse conditions. Journal of Power Sources 220: 360-372. Figure 1

International Conference on Smart Engineering Materials (ICSEM 2018)

PREFACE2018 International Conference on Smart Engineering Materials (ICSEM 2018) was held in Bucharest, Romania during March 07-09, 2018. ICSEM 2018 was a great success, and academic atmosphere helped participants to exchange scientific and technological ideas and enjoy the material development in the field of smart engineering materials.ICSEM 2018 provided a real platform for researchers, engineers and academicians to further develop Smart Engineering Materials. Distinguished professors were also invited to deliver keynote speeches relating to the latest developments and trends in their respective fields. The keynote speakers included Prof. Pankaj Vadgama from Queen Mary University of London, UK; Prof. Maria Tomoaia-Cotisel from Babes-Bolyai University of Cluj-Napoca, Romania; Prof. Jordi Arbiol from ICREA & Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST.This set of conference proceedings presents a selection of papers submitted to the conference from various universities, research institutes and industries. All papers were subjected to peer-review by conference committee members and a panel of international reviewers. The papers were selected based on the quality and relevance to the conference. This volume presents recent advances in the field of Carbonaceus Materials, Nanomaterials and their Arrangements, Two Dimensional Materials, Non Ferrous Metal Material, Smart and Intelligent Materials, Intelligent Materials Systems, Processing Technology for Functional Materials and etc.We would like to thank all the authors who have contributed to this volume and also to the organizing committee, reviewers, speakers, co-chairpersons, sponsors and all the conference participants for their strong support to ICSEM 2018 to make this a successful event. We look forward to meeting you in ICSEM 2019!Prof. Pankaj VadgamaQueen Mary University of London, UKApril 12, 2018

Effect of link oriented self-healing on resilience of networks

Many real, complex systems, such as the human brain and skin with their biological networks or intelligent material systems consisting of composite functional liquids, exhibit a noticeable capability of self-healing. Here, we study a network model with arbitrary degree distributions possessing natural link oriented recovery mechanisms, whereby a failed link can be recovered if its two end nodes maintain a sufficient proportion of functional links. These mechanisms are pertinent for many spontaneous healing and manual repair phenomena, interpolating smoothly between complete healing and no healing scenarios. We show that the self-healing strategies have profound impact on resilience of homogeneous and heterogeneous networks employing a percolation threshold, fraction of giant cluster, and link robustness index. The self-healing effect induces distinct resilience characteristics for scale-free networks under random failures and intentional attacks, and a resilience crossover has been observed at certain level of self-healing. Our work highlights the significance of understanding the competition between healing and collapsing in the resilience of complex networks.

ERRATUM to ‘Design and Experimental Characterisation of a Morphing Wing with Enhanced Corrugated Skin’

‘Design and Experimental Characterisation of a Morphing Wing with Enhanced Corrugated Skin’ by F Previtali, AF Arrieta and P Ermanni published in Journal of Intelligent Material Systems and Structures 2016; 27(2): 278–292. DOI: https://doi.org/10.1177/1045389X15595296.Owing to errors made at SAGE, the following reference in the above article is incorrect:Previtali F, Arrieta AF and Ermanni P (in press) Investigation of the requirements for passive morphing skins. Smart Materials and Structures.This reference should be replaced with:Previtali F (2015) Morphing wing based on compliant elements. Diss. ETH No. 22705, Department of Mechanical and Process Engineering, ETH Zurich.SAGE apologises to the author and to the readers.

Comments on “Non-Linear Piezoelectric Vibration Energy Harvesting From a Vertical Cantilever Beam with Tip Mass”

This paper first points out the retaining higher order terms in the main equation of previous study(PS)of Friswell et al. (Journal of Intelligent Material Systems and Structures 23(13): 1505–1521, 2012). The equations of motion for the system are derived following energy (Lagrange) based approaches and the correct equation with the extra higher order terms is provided and simulations are redone in the current study (CS).

When nothing is constant but change: Adaptive and sensorial materials and their impact on product design

This article is the preface to the Special Issue of the Journal of Intelligent Material Systems and Structures on occasion of the Symposium A53 ‘MEMS/NEMS for Sensorial and Actorial Materials’ held at the Euromat 2011 Conference, Montpellier, France, September 12-15, 2011. The authors outline the concept of material-integrated sensing and intelligence, which is summarized in the term sensorial materials. Such materials are understood to incorporate sensing, signal and data processing as well as communication facilities to autonomously evaluate their own condition and/or their environment. To achieve these capabilities, bottom-up as well as top-down approaches are currently being discussed. The latter is highlighted in this work. Research efforts towards it range from materials science to sensor and microelectromechanical system (MEMS)/nanoelectromechanical system (NEMS) technology, microelectronics and computer science and were covered in the underlying Euromat symposium. As a specific aspect linked to the envisaged autonomy and a resulting adaptivity, for example, of internal self-representation and data interpretation, potential consequences for engineering design are sketched.

Award-winning Journal of Intelligent Material Systems and Structures articles announced

Award-winning <i>Journal of Intelligent Material Systems and Structures</i> articles announced