F. Algahtani, Karthikram B. Thulasiram, Nashrul M. Nasir, A. Holland
{"title":"Four point probe geometry modified correction factor for determining resistivity","authors":"F. Algahtani, Karthikram B. Thulasiram, Nashrul M. Nasir, A. Holland","doi":"10.1117/12.2034057","DOIUrl":"https://doi.org/10.1117/12.2034057","url":null,"abstract":"The four-point probe technique is well known for its use in determining sheet resistance and resistivity (or effective resistivity) of thin films. Using a standard four-point probe setup, relatively large area samples are required. The convention is that the distance from any probe in the probe arrangement should be at least ten times the probe spacing from the sample boundary in order to use the fixed correction factor. In this paper we show, using computer modelling, how accurate measurements can be made using appropriate correction factors for samples that are either small or of any thickness. For the significant extent of variations used, the correction factor does not vary significantly.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121315952","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}
S. Almalki, F. Algahtani, M. Blackford, M. Alnassar, B. C. Johnson, J. McCallum, A. Holland
{"title":"Investigation of amorphisation of germanium using modeling and experimental processes","authors":"S. Almalki, F. Algahtani, M. Blackford, M. Alnassar, B. C. Johnson, J. McCallum, A. Holland","doi":"10.1117/12.2035093","DOIUrl":"https://doi.org/10.1117/12.2035093","url":null,"abstract":"Crystalline germanium substrates were amorphised to a depth of one micron by ion implantation of germanium ions at a series of relatively high energies and dose. Using the ion implantation modeling software TRIM, this paper compares the amorphisation results from the ion implantation simulations and experimental results from transmission electron microscopy (TEM) analysis of cross-sections of implanted samples. TEM cross-section micrographs show a clear boundary between amorphous and crystalline germanium. The effect of amorphisation of Ge on the subsequent formation of Nickel germanide is demonstrated and one significant issue is the increased depth of NiGe grains formed on a-Ge compared with c-Ge.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133608401","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":"Nanoimprint lithography for microfluidics manufacturing","authors":"G. Kreindl, T. Matthias","doi":"10.1117/12.2035609","DOIUrl":"https://doi.org/10.1117/12.2035609","url":null,"abstract":"The history of imprint technology as lithography method for pattern replication can be traced back to 1970’s but the most significant progress has been made by the research group of S. Chou in the 1990’s. Since then, it has become a popular technique with a rapidly growing interest from both research and industrial sides and a variety of new approaches have been proposed along the mainstream scientific advances. Nanoimprint lithography (NIL) is a novel method for the fabrication of micro/nanometer scale patterns with low cost, high throughput and high resolution. Unlike traditional optical lithographic approaches, which create pattern through the use of photons or electrons to modify the chemical and physical properties of the resist, NIL relies on direct mechanical deformation of the resist and can therefore achieve resolutions beyond the limitations set by light diffraction or beam scattering that are encountered in conventional lithographic techniques. The ability to fabricate structures from the micro- to the nanoscale with high precision in a wide variety of materials is of crucial importance to the advancement of micro- and nanotechnology and the biotech- sciences as a whole and will be discussed in this paper. Nanoimprinting can not only create resist patterns, as in lithography, but can also imprint functional device structures in various polymers, which can lead to a wide range of applications in electronics, photonics, data storage, and biotechnology.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"254 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122556430","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}
M. A. Strack, B. A. Fairchild, A. Alves, Philippe Senn, B. Gibson, S. Prawer, A. Greentree
{"title":"Buried picolitre fluidic channels in single-crystal diamond","authors":"M. A. Strack, B. A. Fairchild, A. Alves, Philippe Senn, B. Gibson, S. Prawer, A. Greentree","doi":"10.1117/12.2035099","DOIUrl":"https://doi.org/10.1117/12.2035099","url":null,"abstract":"We report the generation of sub-surface nanouidic channels from single crystal diamond. To make the channels, we used a combination of ion-beam induced damage and annealing to create a buried, etchable graphitic layer in the diamond. Either laser or focussed ion-beam milling was then used to connect to that layer, and subsequent electro-chemical etching used to remove the graphitic material. The channels had dimensions 100-200 nm thick, 100 μm wide and 300 μm long, which have a total volume around 3 pL; and were around 3 μm below the diamond surface.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"183 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114452978","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}
S. Baratchi, F. Tovar-Lopez, K. Khoshmanesh, M. Grace, W. Darby, P. McIntyre, A. Mitchell
{"title":"A microfluidic platform to study the mechano sensational properties of ion channels","authors":"S. Baratchi, F. Tovar-Lopez, K. Khoshmanesh, M. Grace, W. Darby, P. McIntyre, A. Mitchell","doi":"10.1117/12.2033734","DOIUrl":"https://doi.org/10.1117/12.2033734","url":null,"abstract":"Microfluidic platforms have been widely considered as an enabling technology for studying the ion transport phenomena of cells under precisely controlled shear stresses. Here, we report the application of a unique microfluidic platform to analyze the response of transgenic TRPV4-HEK293 cells in response to different shear stresses and in one field of view. Applying this system, we show the kinetics of calcium signalling at different shear stresses in TRPV4 positive cells and elucidate the threshold of their response. We show that there is direct correlation between the magnitude of shear stress and percentage of cells that are able to sense that level of shear. Further, we show that shear stress-induced elevation in intracellular calcium levels ([Ca2+]i) is through calcium influx from extracellular sources. The results demonstrate that the microfluidic system has unique capabilities for analysis of shear stress on adhesive cells and that it should be amenable to moderate throughput applications.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121796970","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}
Shisong Li, Jigui Cheng, Kui Xie, Peipei Li, Yucheng Wu
{"title":"Composite anode La0.8Sr0.2MnO3 impregnated with cobalt oxide for steam electrolysis","authors":"Shisong Li, Jigui Cheng, Kui Xie, Peipei Li, Yucheng Wu","doi":"10.1117/12.2035241","DOIUrl":"https://doi.org/10.1117/12.2035241","url":null,"abstract":"Oxygen-ion conducting solid oxide electrolyzer (SOE) has attracted a great deal of interest because it converts electrical energy into chemical energy directly. The oxygen evolution reaction (OER) is occurred at the anode of solid oxide electrolyzer as the O2- being oxidized and form O2 gas, which is considered as one of the major cause of overpotentials in steam electrolyzers. This paper investigates the electrolysis of steam based on cobalt oxide impregnated La0.8Sr0.2MnO3 (LSM) composite anode in an oxide-ion-conducting solid oxide electrolyzer. The conductivity of LSM is studied versus temperature and oxygen partial pressure and correlated to the electrochemical properties of the composite electrodes in symmetric cells at 800 °C. Different contents of Co3O4 (wt.1%, 2%, 4%, 6%, 8%, 10%) were impregnated into LSM electrode and it was found that the polarization resistance (Rp) of symmetric cells gradually improved from 1.16 Ω•cm2 (LSM) to 0.24 Ω•cm2 (wt.10%Co3O4-LSM). Steam electrolysis based on LSM and wt.6%Co3O4-LSM anode electrolyzers are tested at 800°C and the AC impedance spectroscopy results indicated that the Rp of high frequency process significantly decreased from1.1 Ω•cm2 (LSM) to 0.5 Ω•cm2 (wt.6%Co3O4-LSM) under 1.8V electrolysis voltage and the Rp of low frequency process decreased from 14.9 Ω•cm2 to 5.7 Ω•cm2. Electrochemical catalyst Co3O4 can efficiently improve the electrode and enhance the performance of high temperature solid oxide electrolyzer.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124986779","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}
J. Aylott, M. Clark, L. Marques, F. Pérez-Cota, Richard J. Smith, K. Webb
{"title":"Sound of nano","authors":"J. Aylott, M. Clark, L. Marques, F. Pérez-Cota, Richard J. Smith, K. Webb","doi":"10.1117/12.2035176","DOIUrl":"https://doi.org/10.1117/12.2035176","url":null,"abstract":"Ultrasound is widely used for imaging, measurement and diagnostics in the MHz region and is perhaps most familiar as a medical or non-destructive imaging or measurement tool. In the MHz frequency range the wavelength is typically measured in microns and is many times longer than the wavelength of visible light, limiting its resolution to objects much larger than the nano-scale. It is possible to perform ultrasonic imaging and measurement at much higher frequencies, in the GHz region. Here the acoustic wavelength is typically less than that of light permitting the higher resolutions than optical microscopy and the ability to probe micro and nano-scale objects. At these high frequencies ultrasonics has much to offer the nano-world as a powerful diagnostic tool: it could be used in circumstances where optical microscopy, electron microscopy and probe microscopy cannot, such as inside living objects. Despite the potential that ultrasonics offers for imaging and measurement at the micro and nano-scale, performing ultrasonics at the nano-scale is hampered by many problems that render the techniques typically used in the MHz region impractical. In this paper we discuss some of the practical problems standing in the way of nano-ultrasonics and some of the solutions, especially the use of pico-second laser ultrasonics and the development of nano-ultrasonic transducers and their application to ultrasonic imaging inside living cells.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"329 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122742566","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}
L. Rosa, G. Gervinskas, A. Žukauskas, M. Malinauskas, E. Brasselet, S. Juodkazis
{"title":"Optoplasmonics: hybridization in 3D","authors":"L. Rosa, G. Gervinskas, A. Žukauskas, M. Malinauskas, E. Brasselet, S. Juodkazis","doi":"10.1117/12.2033716","DOIUrl":"https://doi.org/10.1117/12.2033716","url":null,"abstract":"Femtosecond laser fabrication has been used to make hybrid refractive and di ractive micro-optical elements in photo-polymer SZ2080. For applications in micro- uidics, axicon lenses were fabricated (both single and arrays), for generation of light intensity patterns extending through the entire depth of a typically tens-of-micrometers deep channel. Further hybridisation of an axicon with a plasmonic slot is fabricated and demonstrated nu- merically. Spiralling chiral grooves were inscribed into a 100-nm-thick gold coating sputtered over polymerized micro-axicon lenses, using a focused ion beam. This demonstrates possibility of hybridisation between optical and plasmonic 3D micro-optical elements. Numerical modelling of optical performance by 3D-FDTD method is presented.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122918977","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}
Jack Hellerstedt, Jianhao Chen, Dohun Kim, W. Cullen, C. Zheng, M. Fuhrer
{"title":"In situ monitoring of resistivity and carrier concentration during molecular beam epitaxy of topological insulator Bi2Se3","authors":"Jack Hellerstedt, Jianhao Chen, Dohun Kim, W. Cullen, C. Zheng, M. Fuhrer","doi":"10.1117/12.2033659","DOIUrl":"https://doi.org/10.1117/12.2033659","url":null,"abstract":"Bismuth selenide (Bi2Se3) is a three-dimensional strong topological insulator of particular interest due to its relatively large bulk band gap (300 meV), single set of topologically non-trivial surface states, and layered van der Waals structure. However, there are outstanding problems in isolating the surface states of interest from bulk (trivial) conduction: this problem is frequently attributed to doping from selenium vacancies, and atmospheric exposure. To address these questions, we have constructed a system capable of growing thin film bismuth selenide by van der Waals epitaxy with the additional capability to do real time, in situ transport measurements, specifically resistivity and Hall carrier density. Post growth cooling to 15 K, and controlled exposure to atmospheric dopants is possible without breaking vacuum. We have demonstrated in-situ electrical measurements of resistivity and Hall effect which allow monitoring of the charge carrier density and mobility during growth as well as post-growth without breaking vacuum.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122062496","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}
X. Wen, Shujuan Huang, G. Conibeer, S. Shrestha, P. Yu, Yon‐Rui Toh, Jau Tang
{"title":"Optical properties and electron dynamics in carbon nanodots","authors":"X. Wen, Shujuan Huang, G. Conibeer, S. Shrestha, P. Yu, Yon‐Rui Toh, Jau Tang","doi":"10.1117/12.2035308","DOIUrl":"https://doi.org/10.1117/12.2035308","url":null,"abstract":"Carbon nanodots (CNDs) have emerged as fascinating materials with exceptional electronic and optical properties, and thus they offer promising applications in photonics, photovoltaics and photocatalysis. Herein we study the optical properties and electron dynamics in CNDs using steady state and time-resolved spectroscopy. The photoluminescence (PL) is determined to originate from both core and surface. The massive surface fluorophores result in a broad spectral fluorescence. In addition to various synthesis techniques, it is demonstrated that the PL of CNDs can be extended from the blue to the near infrared by thermal assisted growth. Directional electron transfer was observed as fast as femtosecond in CND-graphene oxide nanocomposites from CND into graphene oxide. These results suggest CNDs can be promising in many applications.","PeriodicalId":334178,"journal":{"name":"Smart Materials, Nano-, and Micro- Smart Systems","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2013-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128303466","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}