Multifunctional Materials最新文献

{"title":"UV-triggered photoinsertion of contrast agent onto polymer surfaces for in vivo MRI-visible medical devices","authors":"Anita Schulz, L. Lemaire, A. Béthry, L. Allègre, Maida Cardoso, F. Bernex, F. Franconi, C. Goze-Bac, Hubert Taillades, X. Garric, B. Nottelet","doi":"10.1088/2399-7532/ab0f81","DOIUrl":"https://doi.org/10.1088/2399-7532/ab0f81","url":null,"abstract":"Polymeric materials are largely employed for the manufacturing of implants for various reasons, but they are typically invisible by conventional imaging methods. To improve surgical procedure and postoperative implant follow-up though, biomaterials are needed which allow an accurate and efficient imaging. Here, we present a direct and versatile strategy that allows to covalently immobilize T1 magnetic resonance imaging (MRI) contrast agents at the surface of various clinically relevant polymeric biomaterials. An aryl-azide bearing complex of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and gadolinium (Gd) has been synthesized for easy photografting onto polymer surfaces. Polycaprolactone, polylactide, polyurethane, polyetheretherketone, and polypropylene (PP) have been selected as clinically relevant substrates and successfully functionalized with the photosensitive MRI probe DOTA/Gd. Following in vitro assessment of their biocompatibility and MRI visibility, commercial MRI-visible PP hernia repair meshes (MRI-meshes) have been prepared. MRI-meshes have been implanted in rats for in vivo evaluation of their imaging capacities over 1 month. Histological evaluation and Gd biodistribution studies have been carried out confirming the potential of this straightforward approach to simply yield imageable medical devices.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/ab0f81","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42618238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Challenges in 3D printing of piezoelectric materials","authors":"Sampada Bodkhe, P. Ermanni","doi":"10.1088/2399-7532/ab0c41","DOIUrl":"https://doi.org/10.1088/2399-7532/ab0c41","url":null,"abstract":"Three-dimensional printing (3DP), the fastest growing manufacturing community, in a quest to capitalize its principal advantage of customization is exceedingly seeking functional materials. Piezoelectric materials are one such type of functional material desired for their linear electromechanical and thermoelectric behavior. The ability to 3D print piezoelectric material opens up a new demographic of integrated and personalized smart devices serving from aerospace to biomedical applications. Being self-powered further renders them a competing material for devices used in remote locations: inside the human body, and confined and inaccessible spaces. The review evaluates the significance of 3DP structures over their conventionally fabricated counterparts as well as those of 3D structures over 2D and 1D equivalents. Although, 3DP of these materials is successfully attempted using various techniques, there remain concerns in optimizing the function with the form. This review analyzes the current 3DP techniques available for piezoelectric material and addresses the challenges in realizing ready-to-use piezoelectric sensors and applying them in multi-material printing by resolving the issues associated with electrode formation and poling. As all the current characterization techniques are restricted to 2D geometries, we propose a list of potential techniques to efficiently characterize 3D piezoelectric structures. Finally, a road-map is provided to choose an appropriate 3DP technique and the corresponding material system pertaining to a given application.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/ab0c41","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48569489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating performance of wet unencapsulated PEDOT trilayer actuators operating in air and water","authors":"Saeedeh Ebrahimi Takalloo, A. Fannir, G. Nguyen, C. Plesse, F. Vidal, J. Madden","doi":"10.1088/2399-7532/ab0a9a","DOIUrl":"https://doi.org/10.1088/2399-7532/ab0a9a","url":null,"abstract":"Ionically electroactive devices with no encapsulation dry out in air if a solvent-based electrolyte is used, and exchange ions in wet environments, both of which cause the performance of the device to vary over time. In this paper, we investigate the behavior of bare poly(3, 4-ethylenedioxythiophene) trilayer actuators both in intermittent use and continuous cycling in open air and in water, in order to understand how their response changes with time and solvent loss. Not surprisingly, the devices slow as solvent evaporates, but, unexpectedly, the active displacement increases until a large fraction of the solvent is gone. The electrolyte used in these 360 μm thick devices is a 1 M solution of Bis(trifluoromethane)sulfonimide lithium salt (Li+TFSI−) in propylene carbonate (PC). The trilayers lose all their solvent within 8 d, with ∼40% loss within a day, when stored in an environment with controlled temperature and relative humidity of (23 ± 2)°C and (50 ± 3)%, respectively. The devices’ speeds slow as the PC evaporates from the device (staying within 10% of their initial value after losing ∼20% of its PC content). Intermittent testing shows displacement of the device actually increases until only ∼14% of the PC content remains which would take almost 4 d if the device is stored in the controlled conditions mentioned above. This is largely due to the reduction of thickness in the trilayers, which then leads to higher curvature. Cycling in open air or in water leads to immediate displacement decrease: dropping 60% over one hour cycling in air and over 12 min cycling in water-due to the reduction of charge transfer rate. Overall, for applications where speed is not critical and operation is only needed for a matter of hours or days, encapsulation may not necessary. We expect that encapsulation will be beneficial to maintain the intermittent operation of the device and to maintain speed for longer periods of use (beyond 4 d and 12 h, respectively in the case studied). Encapsulation should also allow a stable displacement amplitude over time.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/ab0a9a","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44368239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Composite bilayered scaffolds with bio-functionalized ceramics for cranial bone defects: An in vivo evaluation","authors":"A. Teotia, D. Raina, H. Isaksson, M. Tägil, L. Lidgren, J. Seppälä, Ashok Kumar","doi":"10.1088/2399-7532/aafc5b","DOIUrl":"https://doi.org/10.1088/2399-7532/aafc5b","url":null,"abstract":"Despite having substantial regenerative capabilities, bone regeneration in critical injuries may be insufficient and require an additional intervention. With advancements in material science and production technology it is now possible to generate complex scaffolds with controlled architectures for repairing these injuries. Additionally, these materials can be functionalized with bioactive molecules to enhance osteoinductivity. In the present work, we developed a multifunctional composite bilayered scaffold (BS), integrating a ceramic nanocement (NC) and macroporous composite scaffold (CG) for cranial injuries, mimicking bone architecture. The scaffolds were functionalized with recombinant human bone morphogenetic protein-2 (rhBMP-2) (BMP) (2 μg/scaffold) and zoledronic acid (ZA) (10 μg/scaffold). We hypothesized that the composite scaffolds would support proliferation of osteoblast progenitor cells and provide controlled release of loaded bioactive molecules to induce bone regeneration. Higher amounts of mineralized tissue (MT) deposition was observed with functionalized scaffolds 12 weeks post in vivo implantation in 8.5 mm critical cranial defect in rats. Contrary to our expectations, BS + ZA functionalized scaffolds had highest MT deposition (13.9 mm3), followed by CG + ZA + BMP with 9.2 mm3 and BS + ZA + BMP with 7.6 mm3 of MT deposition, all significantly higher than non-functionalized CG (7.2 mm3) or BS (4.9 mm3) scaffolds and the empty [Teotia et al 2017 ACS Appl. Mater. Interfaces, 9, 6816–6828] groups. The results supported an osteopromotive multifunctional scaffold implantation in critical defects.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aafc5b","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44266589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Electromechanical properties and structure of stretchable and highly conductive polymer hydrogels","authors":"Yingjun An, K. Iwashita, H. Okuzaki","doi":"10.1088/2399-7532/aaf09c","DOIUrl":"https://doi.org/10.1088/2399-7532/aaf09c","url":null,"abstract":"The stretchable and highly conductive polymer (S-CP) hydrogels were fabricated by casting a water solution of poly(3,4-ethylenedioxythiophene) doped with poly(4-styenesulfonate) (PEDOT:PSS) and polyacrylamide (PAAm) and subsequent swelling in water. The mechanical properties, electrical conductivity, and structure of the S-CP gels with different weight ratios of the PAAm (WPAAm) were investigated by means of the tensile test, four-probe method, scanning electron microscopy (SEM), and electron probe micro analysis (EPMA). It was found that the S-CP gels were composed of soft and stretchable PAAm-rich porous network surrounded by the PEDOT:PSS-rich conductive network layers, exhibiting excellent electrical conductivity (17 S cm−1) and fracture strain (110%) though it contained 92% of water at WPAAm = 64 wt%. Furthermore, the electrical conductivity of the S-CP gel was improved by stretching up to 75% due to the orientation of the PEDOT:PSS-rich conductive network layers so as to keep the resistance constant, which had potential applications to smart electrodes for soft sensors and actuators in a new field of wet electronics using hydrogels, so called ‘gelectronics’.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aaf09c","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45084633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From softening polymers to multimaterial based bioelectronic devices","authors":"M. Ecker, A. Joshi-Imre, R. Modi, C. Frewin, Aldo Garcia-Sandoval, Jimin Maeng, G. Gutierrez-Heredia, J. Pancrazio, W. Voit","doi":"10.1088/2399-7532/aaed58","DOIUrl":"https://doi.org/10.1088/2399-7532/aaed58","url":null,"abstract":"A recent development in bioelectronic devices involves the utilization of multifunctional polymers as substrate material. Dynamically softening, thin-film polymers reduce the mechanical mismatch between device and tissue after implantation and therefore improves the device–tissue interaction. However, when implementing a new material into the fabrication of fully functional and chronically viable devices, there are specific challenges that need to be addressed. The key for all multimaterial devices is to ensure a good adhesion and connectivity between the different layers. That is especially true if one of the materials is sensitive to stimuli such as temperature and moisture. This review will give an overview on the development of a variety of neural interfaces for recording and stimulation with softening shape memory polymers (SMPs) as substrate material. This review discusses specific requirements for device fabrication, testing, and durability.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aaed58","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49161249","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multifunctional structural polymer electrolytes via interpenetrating truss structures","authors":"I. R. Beringer, M. Walter, J. Snyder, E. Wetzel","doi":"10.1088/2399-7532/aaee16","DOIUrl":"https://doi.org/10.1088/2399-7532/aaee16","url":null,"abstract":"Multifunctional structures such as mechanical load-bearing batteries and supercapacitors require electrolytes that possess both mechanical robustness and high ionic conductivity. In this study, we use additive manufacturing to build three-dimensional interpenetrating structures as model systems for structural electrolytes. Maxwell truss structures with varying solid volume fractions were fabricated by printing thermoplastic molds using fused filament fabrication, injecting and curing epoxy resins, and then etching away the mold. These unit cells were then subject to uniaxial compression to characterize mechanical stiffness, and intercalated with liquid electrolyte with a form-fitting test cell to measure system ionic conductivity. Finite element simulations of the truss structures provide good agreement with the experimental data, and are then used to calculate shear properties that would be difficult to measure experimentally. The results show that the present truss systems provide superior multifunctional properties compared to prior structural polymer electrolyte systems, and suggest that segregated truss structures are a promising approach for creating multifunctional systems.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aaee16","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48790511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cytocompatible magnetostrictive microstructures for nano- and microparticle manipulation on linear strain response piezoelectrics","authors":"Zhuyun Xiao, Reem Khojah, M. Chooljian, R. Conte, J. Schneider, Kevin Fitzell, R. Chopdekar, Yilian Wang, A. Scholl, Jane P. Chang, G. Carman, J. Bokor, D. Di Carlo, R. Candler","doi":"10.1088/2399-7532/aae4d7","DOIUrl":"https://doi.org/10.1088/2399-7532/aae4d7","url":null,"abstract":"In this work, we investigate polycrystalline Ni and FeGa magnetostrictive microstructures on pre-poled (011)-cut single crystal [Pb(Mg1/3Nb2/3)O3]1−x-[PbTiO3]x (PMN-PT, x ≈ 0.31) with linear strain profile versus applied electric field. Magnetostrictive microstructure arrays with various geometries are patterned on PMN-PT. Functionalized magnetic beads are trapped by localized stray fields originating from the microstructures. With an applied electric field, the magnetic domains are actuated, inducing the motion of the coupled particles with sub-micrometer precision. This work shows promise of using energy-efficient electric-field-controlled magnetostrictive micro- and nanostructures for manipulating magnetic beads via a linear strain response. The work also demonstrates the viability of cells suspended in solution on these structures when subject to applied electric fields, proving the cytocompatibility of the platform for live cell sorting applications.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aae4d7","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47600951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal phosphotungstinate concentration for polypyrrole linear actuation and energy storage","authors":"Zane Zondaka, Madis Harjo, Md. Asaduzzaman Khan, T. T. Khanh, T. Tamm, R. Kiefer","doi":"10.1088/2399-7532/aae8a4","DOIUrl":"https://doi.org/10.1088/2399-7532/aae8a4","url":null,"abstract":"Phosphotungstic acid (PTA) and the phosphotungstinates have been shown to be beneficial additives for polypyrrole (PPy) electropolymerization. The goal of this work was to study the PTA concentration effect on the electrodeposition of PPy doped with dodecylbenzenesulfonate (DBS), in view of electronic, linear actuation and sensory properties. Cyclic voltammetry, square wave potential steps and square wave amperometry conducted with isometric and isotonic electro-chemo-mechanical deformation measurements were performed in aqueous lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) electrolyte. The films deposited from 0.01 M PTA showed the highest strain—as much as 20%. The highest conductivities, however, were obtained with films deposited from 0.005 M PTA—in range of 44 S cm−1, accompanied by a high specific capacitance of 223 F g−1. The highest PTA concentration (0.1 M) resulted in qualitatively different film properties and behavior.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aae8a4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47160821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Polypyrrole actuators: the effects of polymer thickness and voltage scan rate on fractional charging and isotonic actuation strain","authors":"Wen Zheng, Philip G. Whitten, G. Spinks","doi":"10.1088/2399-7532/aae3e0","DOIUrl":"https://doi.org/10.1088/2399-7532/aae3e0","url":null,"abstract":"For conducting polymer actuators to be practically useful, they need to be able to generate large forces and displacements and respond quickly. The simplest way to generate larger forces is to produce thicker actuators, but this approach has a negative impact on the response time. The effects of polypyrrole film thickness and voltage scan rate on the electrochemical actuation strain rate are investigated in this study. The rate of oxidative charging is shown to follow a standard Fickian diffusion model suggesting that the migration of ions into the polymer from the electrolyte is the dominant rate-determining mechanism. The migration rate is slow with full oxidation requiring several minutes for film thicknesses of just 10 μm. The free strains generated were found to be directly proportional to the oxidative charge passed. The isotonic actuation strains were additionally reduced by increasing applied stress and this effect was attributed to the increase in Young’s modulus that occurs during polypyrrole oxidation. A simple model is presented that predicts the change in modulus during oxidation and gives reasonable estimates of the isotonic actuation for PPy actuators of different thickness and when subjected to different stresses.","PeriodicalId":18949,"journal":{"name":"Multifunctional Materials","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1088/2399-7532/aae3e0","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41576496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}