Nanostructure devices and fabrication method

An ion flux is directed to a carbon nanotube to permanently shape, straighten and/or bend the carbon nanotube into a desired configuration. Such carbon nanotubes have many properties that make them ideal as probes for Scanning Probe Microscopy and many other applications

Nanogap Device: Fabrication and Applications

A nanogap device as a platform for nanoscale electronic devices is presented. Integrated nanostructures on the platform have been used to functionalize the nanogap for biosensor and molecular electronics. Nanogap devices have great potential as a tool for investigating physical phenomena at the nanoscale in nanotechnology. In this dissertation, a laterally self-aligned nanogap device is presented and its feasibility is demonstrated with a nano ZnO dot light emitting diode (LED) and the growth of a metallic sharp tip forming a subnanometer gap suitable for single molecule attachment. For realizing a nanoscale device, a resolution of patterning is critical, and many studies have been performed to overcome this limitation. The creation of a sub nanoscale device is still a challenge. To surmount the challenge, novel processes including double layer etch mask and crystallographic axis alignment have been developed. The processes provide an effective way for making a suspended nanogap device consisting of two self-aligned sharp tips with conventional lithography and 3-D micromachining using anisotropic wet chemical Si etching. As conventional lithography is employed, the nanogap device is fabricated in a wafer scale and the processes assure the productivity and the repeatability. The anisotropic Si etching determines a final size of the nanogap, which is independent of the critical dimension of the lithography used. A nanoscale light emitting device is investigated. A nano ZnO dot is directly integrated on a silicon nanogap device by Zn thermal oxidation followed by Ni and Zn blanket evaporation instead of complex and time consuming processes for integrating nanostructure. The electrical properties of the fabricated LED device are analyzed for its current-voltage characteristic and metal-semiconductor-metal model. Furthermore, the electroluminescence spectrum of the emitted light is measured with a monochromator implemented with a CCD camera to understand the optical properties. The atomically sharp metallic tips are grown by metal ion migration induced by high electric field across a nanogap. To investigate the growth mechanism, in-situ TEM is conducted and the growing is monitored. The grown dendrite nanostructures show less than 1nm curvature of radius. These nanostructures may be compatible for studying the electrical properties of single molecule

Writing 3D nanomagnets using focused electron beams

Focused electron beam induced deposition (FEBID) is a direct-write nanofabrication technique able to pattern three-dimensional magnetic nanostructures at resolutions comparable to the characteristic magnetic length scales. FEBID is thus a powerful tool for 3D nanomagnetism which enables unique fundamental studies involving complex 3D geometries, as well as nano-prototyping and specialized applications compatible with low throughputs. In this focused review, we discuss recent developments of this technique for applications in 3D nanomagnetism, namely the substantial progress on FEBID computational methods, and new routes followed to tune the magnetic properties of ferromagnetic FEBID materials. We also review a selection of recent works involving FEBID 3D nanostructures in areas such as scanning probe microscopy sensing, magnetic frustration phenomena, curvilinear magnetism, magnonics and fluxonics, offering a wide perspective of the important role FEBID is likely to have in the coming years in the study of new phenomena involving 3D magnetic nanostructures

太陽電池応用に向けた半導体ナノ構造体配列の形成と評価に関する研究

関西大

Writing 3D Nanomagnets Using Focused Electron Beams.

Focused electron beam induced deposition (FEBID) is a direct-write nanofabrication technique able to pattern three-dimensional magnetic nanostructures at resolutions comparable to the characteristic magnetic length scales. FEBID is thus a powerful tool for 3D nanomagnetism which enables unique fundamental studies involving complex 3D geometries, as well as nano-prototyping and specialized applications compatible with low throughputs. In this focused review, we discuss recent developments of this technique for applications in 3D nanomagnetism, namely the substantial progress on FEBID computational methods, and new routes followed to tune the magnetic properties of ferromagnetic FEBID materials. We also review a selection of recent works involving FEBID 3D nanostructures in areas such as scanning probe microscopy sensing, magnetic frustration phenomena, curvilinear magnetism, magnonics and fluxonics, offering a wide perspective of the important role FEBID is likely to have in the coming years in the study of new phenomena involving 3D magnetic nanostructures

Fabricating Cost-Effective Nanostructures for Biomedical Applications

In this thesis we described inexpensive alternatives to fabricate nanostructures on planar substrates and provided example applications to discuss the efficiency of fabricated nanostructures. The first method we described is forming large area systematically changing multi-shape nanoscale structures on a chip by laser interference lithography. We analyzed the fabricated structures at different substrate positions with respect to exposure time, exposure angle and associated light intensity profile. We presented experimental details related to the fabrication of symmetric and biaxial periodic nanostructures on photoresist, silicon surfaces, and ion-milled glass substrates. Behavior of osteoblasts and osteoclasts on the nanostructures was investigated. These results suggest that laser interference lithography is an easy and inexpensive method to fabricate systematically changing nanostructures for cell adhesion studies. We also used laser interference lithography to fabricate plasmonic structures. Fabrication details of gold nanodisk arrays were described. Experimental and simulation results show that those structures are suitable to develop highly sensitive plasmonic sensors. As a second fabrication method we described the growth of surface immobilized gold nanoparticles with organometallic chemical vapor deposition (OMCVD) on amine terminated surfaces. Samples fabricated using different deposition times were characterized by UV-Vis spectroscopy and scanning electron microscopy. Particle stability on the samples was tested by washing and rinsing treatments with various organic solvents. The size, interparticle distance, and shape of the gold nanoparticles demonstrated that OMCVD is a simple, economical, and fast way to fabricate surface-bonded and stable gold nanoparticles. The plasmonic properties, the stability of the particles and the biotin-streptavidin test showed that these OMCVD-grown gold nanoparticles are suitable for reproducible, low noise and highly sensitive biosensing applications. We further investigated the similar-to-real-life biosensing capabilities of the OMCVD-grown nanoparticles. Conventional antibody immobilization methods using biotin-streptavidin affinity, introduces additional chemistry and distance between the surface and the recognition sites and decreases the sensitivity. With the new recognition chemistry, epidermal growth factor receptor (EGFR) antibody recognition sites were directly immobilized on AuNP surfaces to decrease the distance between the sensor surface and the recognition sites for detecting EGFR antigens. In comparison with the literature, we obtained increased signal response with further optimization possibilities

Latihan industri membuka peluang pekerjaan kepada graduan lepasan politeknik Malaysia

Tujuan kajian ini dilaksanakan untuk menilai sumbangan latihan industri terhadap peningkatan kemahiran pelajar-pelajar Diploma Teknologi Maklumat di Politeknik. Tiga kemahiran insaniah yang diskopkan iaitu kemahiran teknikal, kemahiran komunikasi dan pengetahuan dalam bidang teknologi maklumat. Responden dipilih secara rawak iaitu 75 responden dari Politeknik Johor Bharu dan 28 responden dari Politeknik Tuanku Syed Sirajuddin. Data dianalisis secara diskriptif menggunakan perisian Statistic Package of Social Science (SPSS). Taburan min dan sisihan piawai digunakan untuk analisis kajian ini. Berdasarkan kajian yang dijalankan, pihak industri telah menerapkan kemahirankemahiran ini kepada para pelajar (skor min = 3.96). Tahap kemahiran komunikasi pelajar juga menunjukkan berada pada tahap yang tinggi (skor min = 4.06) kecuali sebahagiannya menunjukkan tahap penguasaan yang sederhana iaitu kemahiran berkomunikasi dalam bahasa Inggeris (skor min = 3.17), pengetahuan pelajar dalam bidang teknologi maklumat berada pada tahap (skor min = 3.97) dan kemahiran teknikal pelajar berada pada tahap (skor min = 3.83). Bagi faktor demografi jantina tidak terdapat perbezaan yang signifikan pengaruh jantina untuk ketiga-tiga kemahiran yang diterapkan. Selain itu, kajian ini juga telah menggariskan faktor keberkesanan program latihan industri mengikut keutamaannya. Secara keseluruhannya, latihan industri yang dijalankan telah dapat meningkatkan kemahiran para pelajar

Photoluminescence Characterization of Patterned Quantum dots and Inverse Quantum dots

The ever increasing demand for oil and its limited supply have forced us to look for alternate sources of energy. Solar energy offers a cheap, alternate form of energy. The efficiency of a solar cell is set by the Shockley-Queisser limit and is currently very low. New techniques to increase the efficiency of solar cells are being explored. Quantum dots and inverse quantum dots are promising future ways to increase the efficiency of solar cells through multiple exciton generation. In this thesis, the fabrication and characterization of defect-free quantum dots and anti-dots are discussed

Towards outperforming conventional sensor arrays with fabricated individual photonic vapour sensors inspired by Morpho butterflies.

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Combining vapour sensors into arrays is an accepted compromise to mitigate poor selectivity of conventional sensors. Here we show individual nanofabricated sensors that not only selectively detect separate vapours in pristine conditions but also quantify these vapours in mixtures, and when blended with a variable moisture background. Our sensor design is inspired by the iridescent nanostructure and gradient surface chemistry of Morpho butterflies and involves physical and chemical design criteria. The physical design involves optical interference and diffraction on the fabricated periodic nanostructures and uses optical loss in the nanostructure to enhance the spectral diversity of reflectance. The chemical design uses spatially controlled nanostructure functionalization. Thus, while quantitation of analytes in the presence of variable backgrounds is challenging for most sensor arrays, we achieve this goal using individual multivariable sensors. These colorimetric sensors can be tuned for numerous vapour sensing scenarios in confined areas or as individual nodes for distributed monitoring.We would like to acknowledge H. Ghiradella (University at Albany), M. Blohm and S. Duclos (GE) and V. Greanya, J. Abo-Shaeer, C. Nehl and M. Sandrock (DARPA) for fruitful discussions. This work has been supported in part from DARPA contract W911NF-10-C-0069 ‘Bio Inspired Photonics’ and from General Electric’s Advanced Technology research funds. The content of the information does not necessarily reflect the position or the policy of the US Government

Synthesis And Characterization Of Zero, One And Two Dimensional Metallic And Ceramic Nanostructures

Nanostructured materials are of great interest because the properties of a material at the nanoscale may differ significantly from the properties of the same material in the bulk form. This has led to a lot of new applications for nanomaterials owing to their unique physical, chemical, electrical, optical and magnetic properties. The present work reports on the synthesis and characterization of zero, one, and two dimensional nanostructured materials. Nanostructured materials in the present study were all grown using a pulsed laser deposition technique. Gold (Au) nanodots (zero-dimensional nanostructure) were grown on silicon (Si) substrates and subsequently used in the growth of titanium nitride (TiN) nanowires (one-dimensional nanostructure). TiN nanowires were grown under different conditions; energy entering the chamber (70 mJ, 80 mJ and 90 mJ) and deposition temperature (600 °C, 700 °C and 800 °C) leading to nanowires of varying length (50 nm – 200 nm), diameter (25 nm-50 nm) and spatial density. Corrosion tests run on TiN nanowires, thin films and magnesium (Mg) bulk showed that TiN nanowires degraded faster than TiN thin films but were still better than Mg bulk. The thesis work has also focused on growing nickel (Ni) thin films (two-dimensional nanostructure) sandwiched between an alumina (Al2O3) substrate and thin film. The nickel films were deposited at different substrate temperatures (liquid nitrogen, room temperature and high temperature) keeping all other deposition parameters the same. Magnetic moment versus magnetic field measurements showed that Ni thin film samples deposited at room temperature and liquid nitrogen temperature had almost the same remanent magnetization; however, samples deposited at liquid nitrogen had the highest saturation magnetization and coercivity. The coercivity values at 10K for Ni thin film samples grown at liquid nitrogen, room temperature, and high temparature were found to be 58.92 Oe and 255.15 Oe respectively