Monica Mir Llorente
Institute for Bioengineering of Catalonia, Spain
Magnetite Nanoparticles; an important hallmark in Alzheimer’s disease
Biography:
Dr. Mònica Mir received the Degree in Chemistry from University Rovira i Virgili, Spain in 1998. In 2006 she received her PhD in biotechnology in the same University. She realized different predoctoral stages at the Institute of Microelectronic in Demokritos, Greece, University of Bath, UK and National Hellenic Research Foundation, Greece. From 2007, she held a postdoctoral position in Max Planck Institute for Polymer Research, Germany. Since 2008, she joins the Institute for Bioengineering of Catalonia (IBEC), Spain as Senior CIBER researcher, combined with her teaching as associate professor in the University of Barcelona. Along her carrier she was managing European, National and industrial research projects, supervising PhD ad Master students and collaborating in congresses organization as coordinator and scientific committee. Her main scientific interests are focused on electrochemical biosensor, integrated in lab-on-a-chip and point of care technologies, implantable sensors, organ-on-a-chip for biomedical applications.
Abstract:
The accumulation of iron in form of magnetite nanoparticles with amyloid peptide is a key process in the development of Alzheimer’s disease (AD)1. However, the origin and role of magnetite inside the AD brain is still unclear2. We have investigated the interaction between these important players in AD with superconducting quantum interference, scanning electron microscope, surface plasmon resonance, and magnetic force microscopy3. The results support the notion that the magnetite-Amyloid ? complex is created before the synthesis of the magnetic nanoparticles, bringing a highly stable interaction of this couple. The capacity of amyloid peptide to bind and concentrate iron hydroxides, the bases for the formation of magnetite, benefits the spontaneous synthesis of these nanoparticles thanks to the catalysis of amyloid peptide4. This symbiotic interaction between amyloid and magnetite helps in the Fe2+ stabilization as well contributes to the aggregation of amyloid monomers to fibrils. A neuronal culture model was used to monitor the changes in spontaneous activity and effective connectivity in amyloid-magnetite affected cultures. The activity of controls was compared in parallel with magnetite, amyloid and magnetite-amyloid complex. A clear spontaneous degradation of neuronal activity is only observed with the amyloid-magnetite dose, disrupting neuron network communities5. Our results demonstrate that magnetite nanoparticles have a more prominent role in this disease, than the previously assigned in the literature, which could help in a better understanding of this neurodegenerative disease and in the development of new AD treatments
Simó Schwartz Jr
CIBBIM-Nanomedicine (VHIR), Spain
Therapeutic applications of extracellular vesicles as vehicles for lysosomal enzymes
Biography:
Director of CIBBIM-Nanomedicine (www.cibbim.eu), a research center focused on new biomedical nanotechnology-based applications. Director Assistant in Basic Research at the Valld’Hebron Research Institute, Barcelona.Deputy director of CIBER-BBN, a center of national excellence in the field of nanotechnology and nanomedicine. Co-founder and Science Advisor of ARGON Pharma SL, and former member of the editorial Board of Nanomedicine-NBM and Eur. J. Nanomedicine. External science advisor of the European Nanomedicine Characterization Laboratory (EU-NCL). Holds 14 patents, most transferred to leading companies of the biotech and pharma sectors and coauthors more than 90 papers in high impact factor journals. Honorary Board member of Precision Nanomedicine journal, he also acts as coordinator and partner of several research international EU projects involving SME’s and large Pharma companies. Coordinator for technology transfer at CIBER-BBN, he was recently appointed as President of the European Society of Nanomedicine and Executive Board member of the International Society of Nanomedicine.
Abstract:
Extracellular Vesicles (EVs), comprising microparticles, exosomes and othersecreted vesicles, are naturally occurring delivery systems produced by most celltypes. EVs have been described as fully biocompatible submicron-sized vehicleswith high transfection capacity and low immunogenic responses, especially when produced in autologous systems. In this work, we propose the use of EV as direct delivery platforms for proteins defective in lysosomal storage disorders (LSD).
LSDs are congenital rare diseases caused by the lack or malfunction of a lysosomal protein, mainly enzymes. Note worthy, most LSDs are currently treated with enzyme replacement therapy (ERT). This approach is based in periodic intravenous infusions of human recombinant enzymes. Nevertheless, as in other protein therapeutics, ERT has important drawbacks, including poor bio distribution, lowenzyme half-life, inability to cross the blood brain barrier and high immunogenicity, which often limits it efficacy.
In this scenario, we isolated and characterized EVs from a CHO cell line over expressing the alpha-galactosidase A (GLA), the defective enzyme in Fabry disease, with a myc-his tag (cmychis). In our hands, EVs containing GLA (EVs-GLA) were rapidly uptaken by target cells and driven directly to the lysosomes, where the exogenous GLA enzyme could restore lysosomal functionality. Indeed, the GLA in EVs had a higher specific activity (6-fold) and greater efficacy reducing the Gb3substrate accumulations (3-fold) than the free GLA enzyme or the Algasidase alfa in clinical use. Tolerability and biodistribution assays showed that intravenously administered EVs accumulate mainly in liver and spleen but also in kidneys, without causing any deleterious side-effect. Finally, GLA knock-out mice treated with EVGLA showed a greater Gb3 reduction in plasma and kidneys compared to those receiving free GLA or Algasidase alfa. Additional assays are being conducted to test the blood brain barrier crossing and the generation of auto-antibodies in EV-GLA treated mice compared to their controls. Studies have been also extended to other LSD, such Sanfilippo, with promising results.
Overall, our results demonstrate that EVs from cell lines over expressing lysosomal enzymes work as natural drug delivery systems for LSD, improving the stability and the efficacy of the cargo.
Jeremiah Rushchitsky
S.P. Timoshenko Institute of Mechanics, Ukraine
Two Basic Features of Continuum Description of Nanocomposite Materials
Biography:
Professor Jeremiah Rushchitsky is working as the Head of Department of Rheology at S.P. Timoshenko Institute of Mechanics (Kyiv, Ukraine) and Professor of Mathematics at Igor Sikorsky KyivNationalTechnical University. He is Member of the National Academy of Sciences of Ukraine, Representative of Ukraine in the International Union of Theoretical and Applied Mechanics (IUTAM), Honorary Professor of University of Aberdeen etc. His scientific results are related to mechanics of materials (theory of elasticity, theory of viscoelasticity, theory of piezoelasticity, theory of solid mixtures), linear and nonlinear wave theories (harmonic and solitary waves), wavelet analysis as applied to mechanics of materials, macro-, micro-, and nano-mechanicsofcompositematerials.J.Rushchitskyis theauthorof560publications,including16 books and text-books. He is well-known in the international community of mechanicians. For example, his e-book “Theory of Waves in Materials” is downloaded about 700,000 times.
Abstract:
Two basic features of continuum description of nanocomposite materials are discussed in the framework of structural mechanics of materials. First a continuum as a basic notion in mechanics of materials is considered, where the principle of continualization is stated and the notion of repre-sentative volume is introduced. Then some facts from the theory of com-posite materials are shown and commented. It is noted that the composite materials are thought as the structurally inhomogeneous continuums and can be studied within the continuum approach, when the concrete prob-lems are solved mathematically with aim of differential equations. The first feature is formulated as invalidity of the principle of continualiza-tion in some types of nanoformations used as fillers in nanocomposite materials. It is stressed that the approach to materials based on principle of continualization was re-comprehended in twenty century, when the mechanics of composite materials was throve. First of all, the importance of internal structure of materials was acceptedand the geometrical para-meter was introduced, which characterizes the mean value of minimal diameters of granules for materials of granular structure, minimal dia-meters of cross-sections of fibers for materials of fibrous structures, minimal thicknesses of layers for materials of layered structure. This resulted in division of the mechanics of materials on macro-,meso-, and micro-mechanics. A progress in nanotechnologies made possible the development of theoretical analysis of nanocomposite materials. It is concluded thatcontinualization of nanoformations seems problematic in many cases and their physical properties both evaluated and determined from the indirect tests should be considered critically. The second feature is stated as necessity of transition from the two-component structure to the three-componentstructureof nanosized composite materials. Also, the kind of nano-composites is considered, which need the four-component models. Both features are commented and accompanied by examples.
During last three years A.Guz published 4 books and about 30 articles in mechanics and J.Rushchitsky published 1book and about 20 articles in mechanics
Pierre Saint-Grégoire
Collaborating Academics, France
Framework structure crystals revisited
Biography:
Pierre SAINT-GRÉGOIRE has been researcher in CNRS (National Centre for Scientific Research), France - Montpellier university and Toulouse (CEMES laboratory) before reaching a position of professor (Toulon and Nîmes universities). He was also involved in Africa as professor and special adviser of african ministers for high education and research for development. He works in the fields of structural phase transitions, incommensurate phases, ferroic materials, and materials for photovoltaics. He is now the president of the NGO Collaborating Academics. Defensor of academic freedom, he is also convinced that « Science is the motor of development, and knowledge is a powerful tool against poverty », and is nowadays fully involved in international collaborations, development, scientific communication, and open scientific edition.
Abstract:
So called Framework structures (FWS) are crystalline materials in which there exist atomic or ionic rigid units that are strongly linked to each other. The most known example is that of perovskites where the corresponding units are octahedra that share corners. The parent crystalline structure is cubic, but there exist in nature different structural arrangements with different symmetries, as in Aurivillius phases, in layered perovskites, or in tungsten bronzes where octahedra are organized in such a way that the symmetry is lower. Units may also be tetrahedral as in quartz-like materials or in silicates. The framework structures, generally built of rigid AXnpolyhedra linked by common vertices (or edges) attract much attention for several reasons: many mineral-forming compounds widely spread in the Earth crust belong to this family; many FWSs exhibit phase-transition behaviour under temperature or pressure variation; many FWSs are ferroic or multiferroic materials, some of them exhibit anomalous thermal dilatation properties; many crystalline materials with interesting applications in various domains, belong to this family. The number of phases and crystal symmetries encountered in FWSs is considerable and may be understood by models of tilting rigid units.Linkage of the units by common vertices or edges allows the units to accomplish concordant rotations without internal deformation. Such deformations give rise to the soft phonon modes called Rigid Units Modes (RUMs). Condensation of a RUM can trigger the symmetry breaking structural transformation which results in emergence of a new structure with tilted polyhedra.
In this review we introduce the main crystal phases belonging to the FWS and present the analysis of RUMs in some of them. We show that there exists a new type of excitation called maximally localized RUMs (MLRUMs), that allows a better understanding of these materials.
Josef Havel
Masaryk University, Czech Republic
Mass Spectrometry for characterization of nano materials. Applications, problems and perspectives
Biography:
Prof. Josef Havel, since 1990 full univ. professor in Analytical Chemistry at Masaryk University, Brno, Czech Republic, Head of MALDI TOF MS laboratory. He is mostly involved in MALDI TOF mass spectrometry of both organic and inorganic materials, chalcogenide glasses, clusters, nanodiamonds, graphene, nano-composites, etc. Also active in applications of artificial intelligence methods esp. Artificial Neural Networks in science, including optimization and/or medical diagnosis.
Abstract:
Statement of the problem:Mass spectrometry, especially Matrix Assisted Laser Desorption Ionisation (MALDI) Time Of Flight (TOF) Mass Spectrometry (MS) is the key instrumental technique for characterization of biological samples in proteomics, biological and medicinal sciences and it is well established and extensively used while MS of inorganics or nanomaterials is not so frequent and well developed. Matrices are seldom and LDI is mostly applied.
The aim is to overview and evaluate the use of MS for characterisation of nano materials (nano particles) and to discuss the advantages/ problems on selected examples:
(i) Generation, characterization, analysis and use of nano-particles
(ii) MS of chalcogenide glasses, high-density phase-change memories materials, especially (iii) Laser ablation synthesis using mass spectrometer as a kind of synthetizer(iv) Generation and use of clusters of monoisotopic elements for calibration in MS and characteriation of the composites.
Fig.1 shows scheme of MS analysis, Laser Ablation and/or LDI of nano-materials.
Findings: LDI TOF MS is suitable method to generate and characterize clusters whilevia computer modeling isotopic patterns can be resolved. Composition of clusters represents structural fragments of the materials and mass spectrometer can be considered as a kind of efficient synthetizer.
Image
Fig.1A Scheme of MS analysisBIsotopic pattern of Ga5Se7- cluster
Ivan Kelnar
Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Czech Republic
Formation of self-assembled structures in epoxy nanocomposites: Effect of graphene oxide modification
Biography:
Ivan Kelnar is head of the Department of nanostructured polymers and compositesat the Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic.
Fields of research: Crosslinking of polymers with organo-functional silanes; binary and ternary reactive blends with improved balance of mechanical properties; multiphase polymer systems modified with nanofillers (NF), effect of nanofillers on reactive-induced phase separation in epoxy systems.Effect of NF on fibril formation and performance in melt- drawn microfibrillar composites.Complex effect of graphite nanoplatelets on parameters of multicomponent polymer systems. The research is mainly focused on structure-properties relationships, mechanisms of mechanical energy absorption and effects of interface. Most of the research is done within national and international projects, published in more than 80 papers.
Ivan Kelnar is head of the Department of nanostructured polymers and compositesat the Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic.
Fields of research: Crosslinking of polymers with organo-functional silanes; binary and ternary reactive blends with improved balance of mechanical properties; multiphase polymer systems modified with nanofillers (NF), effect of nanofillers on reactive-induced phase separation in epoxy systems.Effect of NF on fibril formation and performance in melt- drawn microfibrillar composites.Complex effect of graphite nanoplatelets on parameters of multicomponent polymer systems. The research is mainly focused on structure-properties relationships, mechanisms of mechanical energy absorption and effects of interface. Most of the research is done within national and international projects, published in more than 80 papers.
Abstract:
It is now well accepted that application of different rigid nanoelements (NF) is effective especially in multicomponent polymer systems due to simultaneous structure-directing effects, e.g. ability to replace polymeric compatibilizers. As a result, the role of NF is more complex and can result in enhancement of all basic mechanical parameters. Even more effective can be formation of complex morphologies improving mechanical energy dissipation at impact. Recently, the best parameters of nanocomposites were achieved with graphene and graphene oxide (GO) that also have high potential for modifications.
The effect of NF on phase structure can be even higher for thermosets with reaction-induced phase separation due to a crucial effect on its germination, kinetics, etc. Unlike thermoplastics, GO modifications with low molecular-weight compounds or oligomers are mostly applied. The reason is high performance attained with well exfoliated/bonded GO. At the same time, high ability of polymer chains-modified GO for self-assembly into nature- mimicking morphologies1 indicates promising potential of these compounds to form effective complex structures also in neat and impact-modified epoxy2.
This work deals with a thorough study of the effect of short polymer chains-modified GO on structure and properties of epoxy systems. Unlike few existing studies, focused on achieving high degree of GO exfoliation only, we have aimed at the self-assembling potential of such adducts. Discussed is effect of modifier type, content and geometry of grafting on formation of complex structures as well as difference from themoplastics-based systems. Highlighted are basic aspects leading to nacre-like lamellar structures (Fig a), new “3D” lamellar arrays (Fig b) and potential for deposition on interface in epoxy/carbon fibre composites to form rigid tough interface.
TEM images of epoxy modified with GO-g-polybutadiene
Johanna Valenzuela Oses
University of San Marcos, Peru
Bioadhesive and biocompatible films of Acyclovir – Chitosan/hyaluronic acid for herpes type 1 treatment
Biography:
Abstract:
BACKGROUND
Herpes is a disease caused by a type of virus belonging to the family Herpesviridae that represents an important public health problem worldwide. Available dosage forms (creams and ointments) have many disadvantages, which include insufficient residence time and lack of precise dosage, etc1. Polymeric films based on drug- interpolyelectrolyte complexes (DIPEC) represent an interesting therapeutic strategy that allows controlled drug release, providing a prolonged effect. Besides, they are easy and convenient for topical administration, avoiding high drug plasma concentration, which allow reducing side effects. The aim of this work was to develop and characterize acyclovir-loaded polymeric films for topical treatment of skin wounds by herpes.
METHODS
DIPEC dispersions were prepared by coacervation method. First, chitosan (Ch) was partially neutralized with HCl 1N, followed the addition of acyclovir (ACI) to neutralize 50% of ionizable amine groups of Ch. Then, sodium hyaluronate (HA) 0.005 M was added to neutralize 10% of ionizable amine groups of Ch under constant stirring at 14.000 rpm for 15 minutes. DIPEC dispersions with the formulae Ch-ACI50-HA10 were obtained. Solids of DIPEC were obtained by lyophilization. DIPEC dispersions were characterized by dynamic light scattering (DLS) to evaluate their Z potential (ZP), hydrodynamic diameter (Dh) and polydispersity index, pH measurements and ionic displacement were also evaluated. Solid DIPEC, pure ACI, Ch, HA and the physical mixture (PM) were characterized by thermal analysis (differential calorimetry scanning (DSC) and thermogravimetric analyses (TGA), powder X-ray diffraction (XRPD) and optical microscopy.
Films were obtained using solvent casting method. Glycerin (2% w/v) was added to the DIPEC dispersions as plasticizer. Samples were degassed and dried at 40°C in an on oven until constant weight. Polymeric films were characterized through uniformity weight and content test, swelling, in vitro bioadhesion and release studies.
RESULTS
DIPEC dispersions showed pH=4.19±0.01, Dh=834.3±59.0 nm and ZP=59.6±0.8 mV. Addition of NaCl produced changes in the dispersion pH, which indicated ionic displacement, which revealed ionic interaction between ACI and Ch. However, even after addition of 600-mol % of NaCl, the pH only increased a little, which revealed the strong but reversible union of the drug and the polymers in the DIPEC. DSC showed endothermic peak in the curve of ACI and PM, while this was not present in the solid DIPEC. TGA curves showed two thermal events for the DIPEC, at about 100°C, which could be assigned to a loss of water and at 275°C which indicated the drug decomposition. XRPD of DIPEC showed a characteristic pattern of an amorphous solid. XRDP of the PM and ACI showed the characteristics peaks of ACI, denoting its crystalline nature. Moreover, image of optical microscopy showed birefringence phenomenon for PM and ACI, while the DIPEC could not be observed under polarized light due to their amorphous nature. These results indicated that in the DIPEC there is not free drug. The ?lms obtained had excellent ACI content uniformity with very low percentage of coef?cient of variation (lower than 5%), which indicated that the casting solvent method employed was success. A higher sorption capacity was observed in both unloaded and loaded films. In presence of the ?lms the zeta potential of mucin switched from negative to positive, which indicated that electrostatic interactions occur between the ?lms and mucin, thus revealing their bioadhesive properties of the films. In vitro release studies showed a controlled release of ACI from the films.
CONCLUSION
Polymeric films based on DIPEC composed by Ch and HA and loaded with ACI were obtained. They showed promising properties for the treatment of skin wound produced by herpes virus. Further studies regarding effectiveness of them are required to confirm the usefulness for these purposes.
Mohammad Mirjalili
Islamic Azad University, Iran
Investigation of the effects of Graphene oxide nanoparticles and multi-wall carbon nanotubes on conductivity and surface morphology of polyester-viscose fabric
Biography:
Mohammad Mirjalili, Faculty Member at Islamic Azad University, Yazd Branch, Associate Professor of Textile Engineering & Polymer Department, received his M.Sc. (1998) in textile chemistry. Continued his post graduate studies at the Islamic Azad University, Tehran south branch related to dyeing modification of wool fabric with reactive dyes. Received his Ph. D.(2002) in textile chemistry at Islamic Azad University of Tehran south. He conducted more than 21 Project and 9 doctoral research as well as project related to textile chemistry. He has published more than 56 scientific papers and presented at a number of national and international conferences including 12th International Toki Conference on Plasma Physics and Controlled Nuclear Fusion 2001 in Japan, Word Textile Conference AUTEX2009 in Turkey, Nano Technology Science 2010 in Canada, AUTEX 2011 in France and 12th World Textile Conference AUTEX 2012 in Croatia. His scientific work is related to Synthesis of Dyes for textile, Industrial wastewater treatment plant, Nano Technology and Natural Dyes.
Abstract:
Recent developments in the textile industry have led to significant improvements in the performance of non-woven fabrics. In this work, the specimen of the fabrics (polyester/viscose) was first placed under microwave radiation at different times, and then the optimum treatment of treated fabrics (8min) was selected for physical properties and surface morphology Graphene oxide (GO) and Carbon nanotube (CNT) with different percentages were measured with using dispersing agent, washing performance and stability, and physical properties of the fabric. The image of Surface morphology's specimens was, also, photographed by scanning electron microscopy (SEM). After, the electrical conductivity properties of the specimens were measured, according to AATCC2005-76 standards, and subsequently, K/S, %R, and Lab value of specimens analyzed with using reflection spectrophotometer.
Images of SEM fabric containing nanoparticles (Figures 1 and 2) show that for both nanotubes CNT and Go, increasing the amount of nanoparticles to 7 and 9% by weight causes the appearance of some nanoparticles on the fiber surface, the presence of which is a lot more at the 9%. In the less than 7% amounts used, the nanoparticles are predominantly contained within the fiber.
Fig.1. Image of SEM samples of fabric, term of 8min microwave treatment in: a) CNT 3%o.w.f b) CNT 5% c) CNT 7% d) CNT 9%
Fig.2. Image of SEM samples of fabric, term of 8min microwave treatment in: a) GO 3%o.w.f b) GO 5% c) GO 7% d) GO 9%
In fact, the result indicate that optimum electrical resistivity, that is aim of study too, are 9% one weight of fabric nanoparticles on the fabric, and finally, the electrical resistivity for the values ??of 7 and 5%o.w.f of CNT are approximately the same as those of 9 and 7%o.w.f of GO, which is also shown in the statistical results of the central composite design (CCD).
Isabelle Michaud-Soret
Biosciences and Biotechnology Institute of Grenoble (BIG), France
Safer-by-design biocide made of tri-thiol bridged silver nanoparticle assemblies
Biography:
Dr. Isabelle Michaud-Soret has her expertise in bioinorganic chemistry, metal homeostasis and metallic nanoparticles from fate in cellulo to safer-by-design approaches. She is in charge of a research group, BioMet, involving 10 permanent staffs. The main goals of the BioMet group are the understanding of the molecular and cellular mechanisms responsible for transport and regulatory sensing events of metal ions which are all essentials and whose homeostasis is tightly controlled in cells. We are also interested in understanding how metallic stresses generated either by toxic metals (such as Hg) or by metallic nanoparticles (AgNP, ZnONP, TiO2NP…) interfere with the homeostasis of physiological metals(Cu, Zn and Fe). We are also concerned with the mechanistic molecular interactions between these metallic nanoparticles and biomolecules, bioinspired chelator, protein,thiol containing molecules; but also in the Safer-by-Design approachfor the development of bioinspired-coated NPs and NP assemblies.
Abstract:
Silver nanoparticles (AgNPs) are widely used in consumer products for their biocidal activity. AgNP-containing medical devices is also a growing market with applications in dentistry, prosthesis, catheters or wound dressings. Their activity is due to their capacity to release bioavailable Ag(I) ions which is highly toxic for microorganisms inducing alterations of lipid bilayers, proteins and nucleic acidsmaking them a long-lasting biocide. However AgNPs themselves are usually easily released from the product. Besides, AgNPs are highly sensitive to various chemical environment that triggers their transformation, decreasing their activity. Altogether, AgNPs widespread use leads to bacterial resistance and safety concerns for Human and the environment. There is thus a crucial need for improvements. Herein, a proof of concept for a novel biocide based on AgNP assemblies bridged together by tri-thiol bioinspired ligand is presented. The final nanomaterial is stable and less sensitive to chemical environment with AgNPs completely covered by organic molecules tightly bound via their thiol functions. Therefore, these AgNP assemblies can be considered as safer-by-design and innovative biocides, since they deliver sufficient Ag(I) amount for biocidal activity with no release of AgNPs.
Victor Moro
Universitat de Barcelona, Spain
A new high-resolution microscopy technique
Biography:
Victor Moro has his expertise in electronics engineering and biomedical engineering. He is performing his PhD in microelectronics and performing as Adjunct Professor in University of Barcelona in the Faculty of Physics. The PhD he is performing is based on a Horizon 2020 FET-Open project, Chipscope (Grant agreement 737089).
Abstract:
Superresolution microscopy is a new and advanced technique that allows to resolve objects smaller than traditional optical microscopes. Several studies have been done in this subject and there exist various types of microscopy techniques. These techniques can be grouped into two groups, non-fluorescence-based techniques and fluorescence-based techniques. Non fluorescence based techniques are Near Field Random Mapping (NORM) and Near Field Scanning Optical Microscopy (SNOM). Fluorescence based techniques are Stimulated Emission Depletion (STED), Reversible Saturable Optical Linear Fluorescence Transmissions (RESOLFT), Photo-Activated Localization Microscopy (PALM) and Stochastic Optical Reconstruction Microscopy (STORM).
In this work we present the first prototype for a new optical microscopy technique: nano-illumination microscopy. This microscope prototype bases its resolution in spatially resolved illumination. With this microscope the importance of the sensor pixel size and pitch disappears, and the light source size and pitch are what determines the resolution of the microscope. This microscope prototype consists on an array of 64 micro-LED which is distributed in 8 rows and 8 columns. Custom discrete driving electronics were designed to turn on the micro-LED array. The detector used is a SPAD camera designed in AMS 350nm technology with 10 μm diameter pixels. The micro-LEDs size is 5 μm with a pitch of 10 μm. The smallest object observed with this microscope prototype is a 5 μm width line, but by decreasing the pixels size and pitch, which in the next microscope version would be 400nm size with 800nm pitch, there would be an upgrade of the microscope resolution. The final prototype using this technique aims to achieve a resolution below Abbe diffraction limit.
Figure 1. Microscope setup showing LEDs, the Sample Holder with an EBL sample in it and the SPAD detector
Fig. 2. An image taken with our microscope (left) of a line pattern of 5 ?m width. In the right it is shown an image taken with a conventional microscope.
Chris Worrall
TWI Ltd, UK
Perforated composites: Manufacturing, modelling, and industrial applications
Biography:
Chris Worrall is a Principal Project Leader at TWI responsible for composites joining, manufacture, processing and testing. He is a metallurgy and materials science graduate, with a PhD in the impact of composite sandwich materials. Chris has spent ten years in Japan working in the automotive, aerospace, renewable energy and rail transport industries. Before leaving the UK, he worked in a research laboratory on the processing of novel thermoplastic composite materials, improving the toughness of composites, and developing test methods for composite materials. His 30 years of composites experience covers composite-to-metal joining, electromagnetism & dielectric characterisation, mechanical testing of composite materials, finite element analysis, design of composite structures, and manufacturing technology for composite materials. Chris is part of the Surflow™ team at TWI that recently won the Composites UK Innovation award.
Abstract:
Perforated metal panels are currently used in many industries and applications including sound absorbing engine components, leading edge de-icing systems and blast protection panels. Due to the increasing demand for ever more lightweight components, the aerospace industry in particular is trying to exploit composite materials. Perforations of composite materials are currently done using the conventional machining techniques such as drilling and abrasive water jet cutting. However, these techniques cut the load bearing fibres and reduce the efficiency of the composite around the holes.
A project funded by TWI’s Member Companies aims to exploit the benefits of thermoplastic composite materials for perforated structures; a continuation of the Thermally Assisted Piercing (TAP) process that was developed by TWI in 2016 as an innovative mechanical fastening technique. Mechanical testing of the TAP composite specimens indicated superior mechanical properties compared to the drilled composite specimens.
The new process, “Multiple Piercing Perforation Technique,” has the potential of making hundreds of small holes at a time in a thermoplastic composite structure, with fibres displaced around the holes instead of being cut. Mechanical testing and NDT techniques have been used to compare the specimens to the drilled ones.
In parallel to the manufacturing process, Abaqus is used to generate a finite element model of the process. Modelling is a very crucial part of the project, and a 2-D model of the microstructure of the perforated composite has been made. By employing the model information regarding the spatial distribution of the fibres around the holes can be obtained, enabled simulation of the performance of the perforated structure in service. Thus, the time to design the perforated component, and it manufacturing process, will be greatly reduced and the full potential of the thermoplastic composite material can be exploited.
Johan Böhlmark
Lamina Technologies SA, Switzerland
The design of a modern tungsten carbide grades for cutting applications
Biography:
Johan Böhlmark is the Group R&D Manager at Lamina Technologies in Switzerland. He holds a PhD in thin film physics from Linköping University, Sweden. The area of research was within High Power Impulse Magnetron Sputtering (HIPIMS), with special focus on plasma characterization. During 2006 – 2008, Johan was the CEO of a start-up company named ChemfiltIonsputtering AB, that developed and sold power supplies for HIPIMS processes. In 2008, he joined the Sandvik Coromant organization, where he for the next 8 years worked within R&D of industrial cutting tools. Johan held several different positions, such as project manager and R&D Manager. In 2016 he accepted a position as Business Advisor for Umea University Holding AB. Since 2018 he is in his current role at Lamina Technologies.
Abstract:
Industrial cutting tools used for various turning, drilling and milling operations are available in a large variety of geometries and materials choices. For high performance machining operations, the most commonly used material system is coated cemented carbide which has a unique combination of wear resistance, toughness, heat resistance and chemical stability and is available at an affordable price. The combination of substrate material, coating material, different surfaces treatments, each connected to certain process parameters, is often referred to as the tool grade. For any specific application and tool geometry the material choice is of high importance. Choosing the correct grade for a certain application is in many cases crucial in order to have functional and economical manufacturing processes. The wear mechanisms and demands on the tools differ significantly depending on the type of operations, machined material, cutting conditions, machine and the tools micro- and macrogeometry In high speed turning operations under stable conditions, the tools are subjected to high temperatures which in turn can trigger plastic deformation and chemical reactions between the tool and the work piece material. On the other hand, under unstable conditions or heavily interrupted cuts, other wear mechanisms are often dominating. Under these conditions, the dominant mechanisms are often related to the thermal cycling, edge fatigue and different chipping phenomena. In this paper, the designs of modern tool grades are discussed. Optimal material choices are suggested, and examples of different operations with corresponding wear types are presented.