SPIE Micro + Nano Materials, Devices, and Applications最新文献

{"title":"Optical properties of arrays of five-pointed nanostars","authors":"Shaoli Zhu, M. Cortie","doi":"10.1117/12.2201119","DOIUrl":"https://doi.org/10.1117/12.2201119","url":null,"abstract":"The optical properties of nanostructures control the performance of applications that are based on localized surface plasmon resonances. Here we use finite-difference time-domain calculations to explore the effect of geometry and material-of-construction on the transmission and near-field optical intensity of arrays of closely-spaced five-pointed nano-star shapes. We compared isolated solid star shapes to star-shaped nano-gaps set within a surrounding square metal shape. The materials investigated were silver, gold, copper and aluminum. The study showed that both the geometry and material chosen had a significant effect on the resulting transmittance spectra. Transmittance spectra of arrays of solid five-pointed nano-stars did not show any strong absorption peaks in the visible region whereas, in contrast, the arrays of star-shaped nano-gaps set within the metal squares did show strong absorption peaks. However, on closer examination it became obvious that the enhanced electric field of the latter was mostly on the corners of the square metal domains and not actually in or on the star-shaped nano-gaps. Therefore we deduce that arrays of simple metal squares will be more suitable as substrates for surface enhanced Raman spectroscopy than arrays of stars or star-shaped nano-gaps. Gold, silver and copper were suitable choices for the latter type of array. Aluminum was unsuitable, at least for applications in the visible part of the spectrum, because it was associated with relatively weak electric fields.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"270 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132164302","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":"Application of novel iron core/iron oxide shell nanoparticles to sentinel lymph node identification","authors":"Aidan Cousins, Douglas Howard, A. M. Henning, Melanie Nelson, R. Tilley, B. Thierry","doi":"10.1117/12.2202510","DOIUrl":"https://doi.org/10.1117/12.2202510","url":null,"abstract":"Current ‘gold standard’ staging of breast cancer and melanoma relies on accurate in vivo identification of the sentinel lymph node. By replacing conventional tracers (dyes and radiocolloids) with magnetic nanoparticles and using a handheld magnetometer probe for in vivo identification, it is believed the accuracy of sentinel node identification in nonsuperficial cancers can be improved due to increased spatial resolution of magnetometer probes and additional anatomical information afforded by MRI road-mapping. By using novel iron core/iron oxide shell nanoparticles, the sensitivity of sentinel node mapping via MRI can be increased due to an increased magnetic saturation compared to traditional iron oxide nanoparticles. A series of in vitro magnetic phantoms (iron core vs. iron oxide nanoparticles) were prepared to simulate magnetic particle accumulation in the sentinel lymph node. A novel handheld magnetometer probe was used to measure the relative signals of each phantom, and determine if clinical application of iron core particles can improve in vivo detection of the sentinel node compared to traditional iron oxide nanoparticles. The findings indicate that novel iron core nanoparticles above a certain size possess high magnetic saturation, but can also be produced with low coercivity and high susceptibility. While some modification to the design of handheld magnetometer probes may be required for particles with large coercivity, use of iron core particles could improve MRI and magnetometer probe detection sensitivity by up to 330 %.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133645345","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":"Dipole-fiber systems: radiation field patterns, effective magnetic dipoles, and induced cavity modes","authors":"S. Atakaramians, A. Miroshnichenko, I. Shadrivov, T. Monro, Y. Kivshar, S. Afshar","doi":"10.1117/12.2204783","DOIUrl":"https://doi.org/10.1117/12.2204783","url":null,"abstract":"We study the radiation patterns produced by a dipole placed at the surface of a nanofiber and oriented perpendicular to it, either along the radial (r-oriented) or azimuthal (Φ-oriented) directions. We find that the dipole induces an effective circular cavity-like leaky mode in the nanofiber. The first radiation peak of the Φ-oriented dipole contributes only to TE radiation modes, while the radiation of the r-oriented dipole is composed of both TE and TM radiation modes, with relative contribution depending on the refractive index of the nanofiber. We reveal that the field pattern of the first resonance of a Φ-oriented dipole is associated with a magnetic dipole mode and strong magnetic response of an optical nanofiber.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"274 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132928919","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":"Plasmon resonances on opto-capacitive nanostructures","authors":"N. Shahcheraghi, A. Dowd, M. Arnold, M. Cortie","doi":"10.1117/12.2202282","DOIUrl":"https://doi.org/10.1117/12.2202282","url":null,"abstract":"Silver is considered as one of the most desirable materials for plasmonic devices due to it having low loss, low epsilon2, across the visible spectrum. In addition, silver nanotriangles can self-assemble into complex structures that can include tip-totip or base-to-base arrangements. While the optical properties of tip-to-tip dimers of nanotriangles have been quite intensively studied, the geometric inverse, the base-to-base configuration, has received much less attention. Here we report the results of a computational study of the optical response of this latter configuration. Calculations were performed using the discrete dipole approximation. The effect of gap size and substrate are considered. The results indicate that the base-to-base configuration can sustain a strong coupled dipole and various multimode resonances. The pairing of the parallel triangle edges produces a strongly capacitive configuration and very intense electric fields over an extended volume of space. Therefore, the base-to-base configuration could be suitable for a range of plasmonic applications that require a strong and uniform concentration of electric field. Examples include refractometeric sensing or metal-enhanced fluorescence.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114308908","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":"Optical properties of refractory TiN, AlN and (Ti,Al)N coatings","authors":"M. Bilokur, A. Gentle, M. Arnold, M. Cortie, G. Smith","doi":"10.1117/12.2202403","DOIUrl":"https://doi.org/10.1117/12.2202403","url":null,"abstract":"Titanium nitride is a golden-colored semiconductor with metallic optical properties. It is already widely used in room temperature spectrally-selective coatings. In contrast, aluminum nitride is a relatively wide-band gap, non-metallic material. Both nitrides have exceptional thermal stability, to over 1000 °C, but are susceptible to oxidation. We will show here that composite coatings consisting of these materials and their complex oxides have considerable potential for spectrally-selective applications, including at elevated temperatures. In particular, we examine the metastable materials produced by magnetron sputtering. The effective dielectric functions of these materials can be tuned over a wide range by manipulation of their microstructure. This provides a strategy to assemble materials with tunable dielectric functions using a 'bottom-up' approach. The results are compared to those achievable by conventional, 'top-down', planar optical stacks comprised of alternating layers of TiNx and AlN.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123031714","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":"Testing organic toxicants on biomicrofluidic devices: why polymeric substrata can lead you into trouble","authors":"Yushi Huang, R. Cartlidge, F. Zhu, D. Nugegoda, D. Wlodkowic","doi":"10.1117/12.2202393","DOIUrl":"https://doi.org/10.1117/12.2202393","url":null,"abstract":"Advances in microfabrication technologies and manufacturing over last decade, allowed for inexpensive prototyping of microfluidic chip-based devices for biomedical studies in biocompatible and optically transparent elastomeric polymers such as poly(dimethylsiloxane) (PDMS) and thermoplastics such as poly(methyl methacrylate) (PMMA). More resently, advanced additive manufacturing technologies such as stereolithography (SLA), capable of reproducing feature sizes less than 50 μm, pave a way towards a new generation of microfabrication techniques. The latter promise new methods to enable accelerated design, validation and optimisation of optical-grade biomicrofluidic Lab-on-a-Chip (LOC) devices. The main limitation, however, of virtually all polymers that are used to both manufacture LOC devices as well as to provide fluidic interconnects is their significant hydrophobicity. Conventionally the hydrophobic properties were postulated to impede wetting and priming of the polymeric chip-based devices and tubing interconnects. Such issues were often solved with plasma treatment or ethanol priming to help wet the polymeric substrata and also reduce the nucleation and persistence of air bubbles. In this work, we present evidence that use of certain hydrophobic polymers is a significant impediment in performing ecotoxicity tests of organic chemicals on biomicrofluidic devices. We report on electrostatic interaction between polymers and toxicants that lead to non-covalent adsorption and rapid depletion of chemicals from the tested media. This introduces a significant bioanalytical bias irrespectively of the fact that microfluidic tests are preformed under continuous perfusion.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127170225","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":"Microscale resolution fracture toughness profiling at the zirconia-porcelain interface in dental prostheses","authors":"A. Lunt, G. Mohanty, T. K. Neo, J. Michler, A. Korsunsky","doi":"10.1117/12.2199217","DOIUrl":"https://doi.org/10.1117/12.2199217","url":null,"abstract":"The high failure rate of the Yttria Partially Stabilized Zirconia (YPSZ)-porcelain interface in dental prostheses is influenced by the micro-scale mechanical property variation in this region. To improve the understanding of this behavior, micro-scale fracture toughness profiling by nanoindentation micropillar splitting is reported for the first time. Sixty 5 μm diameter micropillars were machined within the first 100 μm of the interface. Berkovich nanoindentation provided estimates of the bulk fracture toughness of YPSZ and porcelain that matched the literature values closely. However, the large included tip angle prevented precise alignment of indenter with the pillar center. Cube corner indentation was performed on the remainder of the pillars and calibration between nanoindentation using different tip shapes was used to determine the associated conversion factors. YPSZ micropillars failed by gradual crack propagation and bulk values persisted to within 15 μm from the interface, beyond which scatter increased and a 10% increase in fracture toughness was observed that may be associated with grain size variation at this location. Micropillars straddling the interface displayed preferential fracture within porcelain parallel to the interface at a location where nano-voiding has previously been observed and reported. Pure porcelain micropillars exhibited highly brittle failure and a large reduction of fracture toughness (by up to ~90%) within the first 50 μm of the interface. These new insights constitute a major advance in understanding the structure-property relationship of this important bi-material interface at the micro-scale, and will improve micromechanical modelling needed to optimize current manufacturing routes and reduce failure.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115520278","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":"Experimental investigation of a nanofluid absorber employed in a low-profile, concentrated solar thermal collector","authors":"Qiyuan Li, Cheng Zheng, Sara Mesgari, Yasitha Hewakuruppu, Natasha E. Hjerrild, F. Crisostomo, K. Morrison, Albert Woffenden, G. Rosengarten, Jason A. Scott, R. Taylor","doi":"10.1117/12.2202513","DOIUrl":"https://doi.org/10.1117/12.2202513","url":null,"abstract":"Recent studies [1-3] have demonstrated that nanotechnology, in the form of nanoparticles suspended in water and organic liquids, can be employed to enhance solar collection via direct volumetric absorbers. However, current nanofluid solar collector experimental studies are either relevant to low-temperature flat plate solar collectors (<100 °C) [4] or higher temperature (>100 °C) indoor laboratory-scale concentrating solar collectors [1, 5]. Moreover, many of these studies involve in thermal properties of nanofluid (such as thermal conductivity) enhancement in solar collectors by using conventional selective coated steel/copper tube receivers [6], and no full-scale concentrating collector has been tested at outdoor condition by employing nanofluid absorber [2, 6]. Thus, there is a need of experimental researches to evaluate the exact performance of full-scale concentrating solar collector by employing nanofluids absorber at outdoor condition. As reported previously [7-9], a low profile (<10 cm height) solar thermal concentrating collector was designed and analysed which can potentially supply thermal energy in the 100-250 °C range (an application currently met by gas and electricity). The present study focuses on the design and experimental investigation of a nanofluid absorber employed in this newly designed collector. The nanofluid absorber consists of glass tubes used to contain chemically functionalized multi-walled carbon nanotubes (MWCNTs) dispersed in DI water. MWCNTs (average diameter of 6-13 nm and average length of 2.5-20 μm) were functionalized by potassium persulfate as an oxidant. The nanofluids were prepared with a MCWNT concentration of 50 ± 0.1 mg/L to form a balance between solar absorption depth and viscosity (e.g. pumping power). Moreover, experimentally comparison of the thermal efficiency between two receivers (a black chrome-coated copper tube versus a MWCNT nanofluid contained within a glass tubetube) is investigated. Thermal experimentation reveals that while the collector efficiency reduced from 73% to 54% when operating temperature increased from ambient to 80 °C by employing a MWCNT nanofluid receiver, the efficiency decreased from 85% to 68% with same operating temperature range by employing black chrome-coated copper tube receiver. This difference can mainly be explained by the reflection optical loss off and higher thermal emission heat loss the front surface of the glass tube, yielding a 90% of transmittance to the MWCNT fluid and a 0.9 emissivity of glass pipe. Overall, an experimental investigation of the performance of a low profile solar collector with a direct volumetric absorber and conventional surface absorber is presented. In order to bring nanotechnology into industrial and commercial heating applications,","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131867088","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":"Low-temperature bonded glass-membrane microfluidic device for in vitro organ-on-a-chip cell culture models","authors":"Kyall J. Pocock, Xiaofang Gao, Chenxi Wang, C. Priest, C. Prestidge, K. Mawatari, T. Kitamori, B. Thierry","doi":"10.1117/12.2202461","DOIUrl":"https://doi.org/10.1117/12.2202461","url":null,"abstract":"The integration of microfluidics with living biological systems has paved the way to the exciting concept of “organson- a-chip”, which aims at the development of advanced in vitro models that replicate the key features of human organs. Glass based devices have long been utilised in the field of microfluidics but the integration of alternative functional elements within multi-layered glass microdevices, such as polymeric membranes, remains a challenge. To this end, we have extended a previously reported approach for the low-temperature bonding of glass devices that enables the integration of a functional polycarbonate porous membrane. The process was initially developed and optimised on specialty low-temperature bonding equipment (μTAS2001, Bondtech, Japan) and subsequently adapted to more widely accessible hot embosser units (EVG520HE Hot Embosser, EVG, Austria). The key aspect of this method is the use of low temperatures compatible with polymeric membranes. Compared to borosilicate glass bonding (650 °C) and quartz/fused silica bonding (1050 °C) processes, this method maintains the integrity and functionality of the membrane (Tg 150 °C for polycarbonate). Leak tests performed showed no damage or loss of integrity of the membrane for up to 150 hours, indicating sufficient bond strength for long term cell culture. A feasibility study confirmed the growth of dense and functional monolayers of Caco-2 cells within 5 days.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"9668 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129997038","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":"Illumination dependent carrier dynamics of CH3NH3PbBr3 perovskite","authors":"Sheng Chen, X. Wen, Shujuan Huang, R. Sheng, M. Green, A. Ho-baillie","doi":"10.1117/12.2202176","DOIUrl":"https://doi.org/10.1117/12.2202176","url":null,"abstract":"The excellent light harvesting properties and potentially low cost fabrication of organometal halide perovskites have attracted great attention in their application as solar cell device. Apart from the general advantages of organic-inorganic perovskite, CH3NH3PbBr3 has a larger bandgap (~2.3eV) suitable to be the top cell in a tandem solar device. Here we use steady-state and time-resolved photoluminescence (PL) techniques to investigate the photophysical behaviour of CH3NH3PbBr3 perovskite including its carrier dynamics under continuous illumination. Samples were studied under different illumination conditions and the following observations were made: (1) defect assisted recombination is dominant under low excitation under nano-second scale measurement, (2) bimolecular and Auger recombinations dominate under high excitation under the minute timescale measurement, (3) the magnitude PL decay traces decrease over time under continuous excitation. We propose that both the density of photo-generated free carriers and the density of mobile ions have an impact on the carrier dynamic of CH3NH3PbBr3. This finding provides insights into the photophysical properties of perovskite materials.","PeriodicalId":320411,"journal":{"name":"SPIE Micro + Nano Materials, Devices, and Applications","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134295921","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}