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Micro & Nano Letters, IET

Issue 1 • Date March 2008

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Displaying Results 1 - 6 of 6
  • Stibnite inverse opal

    Page(s): 1 - 6
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (739 KB)  

    A 3D photonic crystal (PhC), synthetic opal, has been constructed by self-assembly of sub-micrometre silica spheres and designed for operation in the visible spectral range. Because of its low refractive index contrast (RIC), this PhC does not exhibit a full photonic band gap (PBG), but this property could be achieved by increasing sufficiently the RIC. It is not easy to find a high refractive index material that is transparent in the visible spectral range, but we report here on a method for producing 3D PhC structures with increased RIC, using incorporation of stibnite (Sb2S3) into a silica opal PhC. The template is infiltrated with the precursor (Sb[CS(NH2)2]3Cl3), with subsequent thermal decomposition at 600degC to form Sb2S3 in the voids of the opal PhC. Formation of Sb2S3 and removal of silica spheres by a chemical etching process can produce a structure that exhibits a full PBG in the visible spectral range. The optical properties of the inverse Sb2S3 opal have been measured and compared with theoretical calculations. View full abstract»

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  • AFM characterisation of silicon-on-insulator push-in plates for Casimir force measurements

    Page(s): 7 - 11
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (292 KB)  

    The use of silicon-on-insulator (SOI) material to fabricate a set of push-in plates for Casimir force measurements is reported. These plates have the advantage of being parallel as fabricated, which is an essential criterion for accurate Casimir force measurements. The roughness of the inner SOI silicon surfaces after the removal of the sacrificial buried oxide and subsequent CO2 critical point drying is characterised. The root-mean-square (RMS) surface roughness measured by atomic force microscopy (AFM) is of the order of 0.25 nm and is shown by calculation to be an insignificant contribution to the measurement of the Casimir force with these plates. View full abstract»

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  • Formation of ultrathin hydrogel films on microcantilever devices using electrophoretic deposition

    Page(s): 12 - 17
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (514 KB)  

    Uniform hydrogel films from micro/nano-hydrogel particles were prepared on the silicon wafers and microcantilevers. These films were assembled on the substrates by using electrophoretic deposition (EPD) method. The microcantilevers coated by such films responded to the environmental pH changes, indicating that the EPD could be used as a new method for modifying microcantilevers. View full abstract»

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  • Theoretical comparison of nanotube materials for drug delivery

    Page(s): 18 - 24
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (245 KB)  

    Carbon nanotubes have gained significant attention as nanocapsules for targeted drug delivery, and recently the behaviour of drugs when encapsulated into carbon nanotubes has been investigated by the present authors. However, there are many other materials which may possibly be more biocompatible or biodegradable and which can form single-walled nanotubes, such as boron nitride, silicon and boron carbide. This Letter theoretically investigates the encapsulation behaviour of the anticancer drug cisplatin when entering boron nitride, silicon and boron carbide single-walled nanotubes, and makes a comparison with the corresponding results for single-walled carbon nanotubes. Of the four materials, it is shown that boron nitride provides the most ideal delivery capsule as it requires the least amount of material for efficient encapsulation and therefore possesses the least toxicity. View full abstract»

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  • Stress-induced curvature of focused ion beam fabricated microcantilevers

    Page(s): 25 - 28
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (403 KB)  

    Microcantilevers with very low spring constants, as required to measure the short-range Casimir force, can be fabricated by focused ion beam thinning of conventional atomic force microscope cantilevers, but the resulting beams have a stress-induced curvature. This can be explained by consideration of the implanted gallium ions and associated damage effects in the etched surface. The problem can be overcome by using a complementary etch method in which top and bottom surfaces of the microcantilever are etched by the same amount. View full abstract»

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  • Properties of graphene produced by the high pressure-high temperature growth process

    Page(s): 29 - 34
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (353 KB)  

    The authors report on a new method for the synthesis of graphene, a mono-layer of carbon atoms arranged in a honey comb lattice, and the assessment of the properties of obtained graphene layers using micro-Raman characterisation. Graphene was produced by a high pressure-high temperature (HPHT) growth process from the natural graphitic source material by utilising the molten Fe-Ni catalysts for dissolution of carbon. The resulting large-area graphene flakes were transferred to the silicon-silicon oxide substrates for the spectroscopic micro-Raman and scanning electron microscopy inspection. The analysis of the G peak, D, T + D and 2D bands in the Raman spectra under the 488 nm laser excitation indicate that the HPHT technique is capable of producing high-quality large-area single-layer graphene with a low defect density. The disorder-induced D peak ~1359 cm-1 while very strong in the initial graphitic material is completely absent in the graphene layers. The proposed method may lead to a more reliable graphene synthesis and facilitate its purification and chemical doping. View full abstract»

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Aims & Scope

Micro & Nano Letters offers express publication of short research papers presenting research conducted at the forefront of micro- and nanoscale science, engineering and technology, with at least one dimension ranging from a few tens of micrometres to a few nanometres.

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Meet Our Editors

Editors-in-Chief
Professor Gwo-Bin Vincent Lee
National Tsing-Hua University, Taiwan

Professor Peter Dobson
University of Oxford, UK