The Experts below are selected from a list of 13422 Experts worldwide ranked by ideXlab platform
Babak Ziaie - One of the best experts on this subject based on the ideXlab platform.
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Selective Nanofiber Deposition through Field-Enhanced Electrospinning
Langmuir, 2009Co-Authors: Zhenwen Ding, Amani Salim, Babak ZiaieAbstract:In this paper, we demonstrate a nanofiber Patterning Technique using field-enhanced electrospinning. Polyethylene oxide (PEO) nanofibers were electrospun on an elastomeric substrate with gold-coated pyramidal protrusions with the majority of fibers being deposited at the tips. The deposited nanofiber spots ranged from 8 × 8 μm2 to 60 × 60 μm2 in size, uniformly covering an area of 5 × 10 mm2. Our experiments also indicate that nanofiber pattern selectivity is highly dependent on the separation/size ratio of the pyramidal protrusions with a ratio of
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Selective nanofibers Patterning via electric field-enhanced electrospinning
2009Co-Authors: Zhenweng Ding, Wan Wardatul Amani Wan Salim, Babak ZiaieAbstract:In this paper, we demonstrate a nanofiber Patterning Technique using field-enhanced electrospinning. Polyethylene oxide (PEO) nanofibers were electrospun on an elastomeric substrate with gold-coated pyramidal protrusions with the majority of fibers being deposited at the tips. The deposited nanofiber spots ranged from 8 × 8 μm2 to 60 × 60 μm2 in size, uniformly covering an area of 5 × 10 mm2. Our experiments also indicate that nanofiber pattern selectivity is highly dependent on the separation/size ratio of the pyramidal protrusions with a ratio of
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Soft mold-dry etch: a novel hydrogel Patterning Technique for biomedical applications.
Conference proceedings : ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and, 2004Co-Authors: Ming Lei, Antonio Baldi, Ronald Siegel, Babak ZiaieAbstract:This paper introduces a novel Patterning Technique for environmentally sensitive hydrogels using a combination of soft mold and dry etch. This method alleviates the need for photoinitiators used in conventional approaches and is applicable to a broad range of hydrogels. This Technique is also compatible with the traditional microfabrication methods thus allowing the integration of hydrogels with microelectronics and MEMS microstructures. Hydrogels of different shapes and sizes were patterned in a batch scale (wafer-level) with resolutions of up to 2.5 microm. The patterned pH-sensitive hydrogels with micron-sized dimensions were able to respond within seconds. Deposited aluminum thin films on top of hydrogel microstructures was used to fabricate environmentally sensitive free standing micro-mirrors with a vertical displacement sensitivity of 7 microm/pH at pH 5.0. These structures open the possibility of fabricating on-chip photonic-based hydrogel microsensors.
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Soft mold-dry etch: a novel hydrogel Patterning Technique for biomedical applications
The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1Co-Authors: Ming Lei, Antonio Baldi, Ronald A. Siegel, Babak ZiaieAbstract:This work introduces a Patterning Technique for environmentally sensitive hydrogels using a combination of soft mold and dry etch. This method alleviates the need for photoinitiators used in conventional approaches and is applicable to a broad range of hydrogels. This Technique is also compatible with the traditional microfabrication methods thus allowing the integration of hydrogels with microelectronics and MEMS microstructures. Hydrogels of different shapes and sizes were patterned in a batch scale (wafer-level) with resolutions of up to 2.5 /spl mu/m. The patterned pH-sensitive hydrogels with micron-sized dimensions were able to respond within seconds. Deposited aluminum thin films on top of hydrogel microstructures was used to fabricate environmentally sensitive free standing micromirrors with a vertical displacement sensitivity of 7 /spl mu/m/pH at pH 5.0. These structures open the possibility of fabricating on-chip photonic-based hydrogel microsensors.
Roman Sobolewski - One of the best experts on this subject based on the ideXlab platform.
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Monolithic Y-Ba-Cu-O structures fabricated using the laser-writing Patterning Technique
Superconductor Science and Technology, 1994Co-Authors: Roman Sobolewski, Win Naing Maung, W. Xiong, W. Kula, Donald P. ButlerAbstract:We report our progress in fabrication of thin-film YBa2Cu3Ox (YBCO) superconducting electronic devices, using a recently developed, laser-writing Patterning Technique. Laser writing allows one to form in the same YBCO film planar patterns that consist of both the oxygen-rich (superconducting) and the oxygen-poor (semiconducting) phases. The patterns are highly uniform with very sharp (less than 1 mu m wide) superconductor-semiconductor interfaces. The oxygen-rich regions possess excellent superconducting properties with critical temperatures as high as those of the best epitaxial films, and critical current densities above 2*106 A cm-2 at 77 K. Simultaneously, the oxygen-poor regions exhibit a disordered-semiconductor-like, thermally activated transport. Below 100 K, they are almost insulating and characterized by relatively low (below 20) dielectric constant and low microwave loss. A number of test structures, consisting of oxygen-rich and oxygen-poor microbridges and coplanar microwave transmission lines and resonators, was fabricated and tested. All these devices are completely monolithic and were used to study DC and microwave transport properties of the oxygen-rich and oxygen-poor YBCO phases.
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Microwave properties of monolithic Y-Ba-Cu-O transmission line devices fabricated by the laser-writing Patterning Technique
High Tc Microwave Superconductors and Applications, 1994Co-Authors: Win Naing Maung, Donald P. Butler, W. Xiong, W. Kula, Roman SobolewskiAbstract:ABSTRACT We report on the microwave characteristics of coplanar strip transmission line devicesfabricated in epitaxial YBaCuO thin films deposited on LaAlO3 substrates using the novel laser-writing Patterning Technique. This Technique uses laser heating to selectively anneal regions of an oxygen depleted YBaCuO thin film to form local superconducting phases. In this manner, superconductive coplanar strip transmission line structures surrounded by the semiconductingYBaCuO phase were patterned with no photomasks, surface contamination or edge degradation.The propagation characteristics of transmission line devices were measured with a HP8510 networkanalyzer from 1 to 20 GHz. At 300 K, the transmission line circuits displayed poor transmissioncharacteristics due to the high conductivity of the semiconducting phase and small conductivityenhancement of the oxygenated regions. As the circuits were cooled below 89 K, the Tc of thesuperconducting phase, the measured 521 was near 0 dB indicating little attenuation along thehigh quality transmission lines. Q-factors as high as 5,000 were measured from coplanar striptransmission line resonator circuits at 6 GHz and 24 K.
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Propagation characteristics of monolithic YBaCuO coplanar strip transmission lines fabricated by laser-writing Patterning Technique
IEEE Microwave and Guided Wave Letters, 1994Co-Authors: Win Naing Maung, Donald P. Butler, W. Xiong, W. Kula, Roman SobolewskiAbstract:We report our studies on the propagation characteristics of YBa/sub 2/Cu/sub 3/O/sub 7/-on-LaAlO/sub 3/ superconducting coplanar strip transmission lines and resonators fabricated with a novel laser-writing Patterning Technique. The measurements were performed in the 0.1 to 15 GHz frequency range at temperatures between 300 and 24 K. We show that at temperatures below the superconducting critical temperature, the S/sub 21/ parameter of our transmission lines was close to 0 dB at all the frequencies, while the Q-factor of the resonator structure was as high as 5000 at 6 GHz and 24 K. The transmission line propagation velocity was about 10/sup 8/ cm/s. Our results indicate that the laser-writing Patterning Technique can be effectively used to fabricate high-quality superconducting microwave elements and circuits. >
Donald P. Butler - One of the best experts on this subject based on the ideXlab platform.
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Monolithic Y-Ba-Cu-O structures fabricated using the laser-writing Patterning Technique
Superconductor Science and Technology, 1994Co-Authors: Roman Sobolewski, Win Naing Maung, W. Xiong, W. Kula, Donald P. ButlerAbstract:We report our progress in fabrication of thin-film YBa2Cu3Ox (YBCO) superconducting electronic devices, using a recently developed, laser-writing Patterning Technique. Laser writing allows one to form in the same YBCO film planar patterns that consist of both the oxygen-rich (superconducting) and the oxygen-poor (semiconducting) phases. The patterns are highly uniform with very sharp (less than 1 mu m wide) superconductor-semiconductor interfaces. The oxygen-rich regions possess excellent superconducting properties with critical temperatures as high as those of the best epitaxial films, and critical current densities above 2*106 A cm-2 at 77 K. Simultaneously, the oxygen-poor regions exhibit a disordered-semiconductor-like, thermally activated transport. Below 100 K, they are almost insulating and characterized by relatively low (below 20) dielectric constant and low microwave loss. A number of test structures, consisting of oxygen-rich and oxygen-poor microbridges and coplanar microwave transmission lines and resonators, was fabricated and tested. All these devices are completely monolithic and were used to study DC and microwave transport properties of the oxygen-rich and oxygen-poor YBCO phases.
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Microwave properties of monolithic Y-Ba-Cu-O transmission line devices fabricated by the laser-writing Patterning Technique
High Tc Microwave Superconductors and Applications, 1994Co-Authors: Win Naing Maung, Donald P. Butler, W. Xiong, W. Kula, Roman SobolewskiAbstract:ABSTRACT We report on the microwave characteristics of coplanar strip transmission line devicesfabricated in epitaxial YBaCuO thin films deposited on LaAlO3 substrates using the novel laser-writing Patterning Technique. This Technique uses laser heating to selectively anneal regions of an oxygen depleted YBaCuO thin film to form local superconducting phases. In this manner, superconductive coplanar strip transmission line structures surrounded by the semiconductingYBaCuO phase were patterned with no photomasks, surface contamination or edge degradation.The propagation characteristics of transmission line devices were measured with a HP8510 networkanalyzer from 1 to 20 GHz. At 300 K, the transmission line circuits displayed poor transmissioncharacteristics due to the high conductivity of the semiconducting phase and small conductivityenhancement of the oxygenated regions. As the circuits were cooled below 89 K, the Tc of thesuperconducting phase, the measured 521 was near 0 dB indicating little attenuation along thehigh quality transmission lines. Q-factors as high as 5,000 were measured from coplanar striptransmission line resonator circuits at 6 GHz and 24 K.
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Propagation characteristics of monolithic YBaCuO coplanar strip transmission lines fabricated by laser-writing Patterning Technique
IEEE Microwave and Guided Wave Letters, 1994Co-Authors: Win Naing Maung, Donald P. Butler, W. Xiong, W. Kula, Roman SobolewskiAbstract:We report our studies on the propagation characteristics of YBa/sub 2/Cu/sub 3/O/sub 7/-on-LaAlO/sub 3/ superconducting coplanar strip transmission lines and resonators fabricated with a novel laser-writing Patterning Technique. The measurements were performed in the 0.1 to 15 GHz frequency range at temperatures between 300 and 24 K. We show that at temperatures below the superconducting critical temperature, the S/sub 21/ parameter of our transmission lines was close to 0 dB at all the frequencies, while the Q-factor of the resonator structure was as high as 5000 at 6 GHz and 24 K. The transmission line propagation velocity was about 10/sup 8/ cm/s. Our results indicate that the laser-writing Patterning Technique can be effectively used to fabricate high-quality superconducting microwave elements and circuits. >
Daisuke Koyama - One of the best experts on this subject based on the ideXlab platform.
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Adhesive cell Patterning Technique using ultrasound vibrations
Ultrasonics, 2019Co-Authors: Kentaro Tani, Koji Fujiwara, Daisuke KoyamaAbstract:Abstract This paper investigated an ultrasound vibration cell Patterning Technique. The ultrasound cell culture dish consisted of a culture dish with a glass bottom and a glass disc with a piezoelectric ring that generated a resonance flexural vibration mode on the bottom of the dish. The growth of HeLa cells on the dish was observed under ultrasound excitation for 24 h. Large ultrasound vibrations on the dish inhibited the cell growth. The acoustic field was predicted with finite element analysis and it was found that the cell growth depended strongly on both the acoustic field in the culture medium and the vibration distribution of the dish. The ultrasound vibrations did not affect the viability of the cells, and the cell growth could be controlled by the flexural vibration of the cultured dish.
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Patterning Technique of adhesive cells using ultrasound flexural vibration
2018Co-Authors: Daisuke Koyama, Kentaro Tani, Koji FujiwaraAbstract:This paper investigated a cell Patterning Technique using ultrasound vibration. The ultrasound cell culture dish consisted of a culture dish with a glass bottom and a glass disc with an ultrasound transducer that generated a resonance flexural vibration mode on the bottom of the dish. HeLa cells were used as adhesives cells, and the growth of cells on the dish was observed under ultrasound excitation for 24 hours. The vibration amplitude was largest at the center of the dish, and the axisymmetric resonance flexural vibration mode with three concentric nodal circles and no nodal line was generated on the bottom of the dish. Large vibrations inhibited the cell growth. The distributions of the sound pressure amplitude and the acoustic radiation force in the culture medium were calculated with finite element analysis and it was found that the cell growth depended strongly on both the acoustic field in the culture medium and the vibration distribution of the dish. The ultrasound vibrations did not affect the viability of the cells, and the cell growth could be controlled by the flexural vibration of the cultured dish.This paper investigated a cell Patterning Technique using ultrasound vibration. The ultrasound cell culture dish consisted of a culture dish with a glass bottom and a glass disc with an ultrasound transducer that generated a resonance flexural vibration mode on the bottom of the dish. HeLa cells were used as adhesives cells, and the growth of cells on the dish was observed under ultrasound excitation for 24 hours. The vibration amplitude was largest at the center of the dish, and the axisymmetric resonance flexural vibration mode with three concentric nodal circles and no nodal line was generated on the bottom of the dish. Large vibrations inhibited the cell growth. The distributions of the sound pressure amplitude and the acoustic radiation force in the culture medium were calculated with finite element analysis and it was found that the cell growth depended strongly on both the acoustic field in the culture medium and the vibration distribution of the dish. The ultrasound vibrations did not affect the v...
Hyung-ho Park - One of the best experts on this subject based on the ideXlab platform.
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Hybrid fabrication of piezoelectric thick films using a sol-infiltration and photosensitive direct-Patterning Technique
Journal of Materials Science, 2015Co-Authors: Hyung-ho ParkAbstract:We propose a hybrid fabrication Technique for piezoelectric thick films using sol-infiltration and a direct-Patterning process. To achieve the demands of high-density and direct-Patterning at a low sintering temperature, a photosensitive lead zirconate titanate (PZT) solution was infiltrated into a lead zinc niobate–lead zirconate titanate (PZN–PZT) thick film. The direct-patterned PZT films were formed on a locally screen-printed thick film, using a photomask and UV light. By optimizing the thickness of the photosensitive PZT layer, the hybrid films that were prepared with a 120-s soaking time of PZT sol showed a very dense and uniform microstructure with a large grain size at a low sintering temperature of 800 °C. It also had enhanced electrical properties. The measured remnant polarization (P_r) and coercive field (E_c) were 14.61 μC cm^−2 and 24.16 kV cm^−1, respectively. The P_r value was over four times greater than those of the screen-printed films. We fabricated array-type piezoelectric resonators with direct-patterned PZN–PZT thick films to show the ability of the direct-Patterning of the PZT thick film on a silicon wafer for actuator and sensor application, especially for mass production.
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Hybrid fabrication of piezoelectric thick films using a sol-infiltration and photosensitive direct-Patterning Technique
Journal of Materials Science, 2015Co-Authors: Jin-hyung Lee, Hyung-ho Park, Jeong Hoon Lee, Sang Kyung Kim, Tae Song KimAbstract:We propose a hybrid fabrication Technique for piezoelectric thick films using sol-infiltration and a direct-Patterning process. To achieve the demands of high-density and direct-Patterning at a low sintering temperature, a photosensitive lead zirconate titanate (PZT) solution was infiltrated into a lead zinc niobate–lead zirconate titanate (PZN–PZT) thick film. The direct-patterned PZT films were formed on a locally screen-printed thick film, using a photomask and UV light. By optimizing the thickness of the photosensitive PZT layer, the hybrid films that were prepared with a 120-s soaking time of PZT sol showed a very dense and uniform microstructure with a large grain size at a low sintering temperature of 800 °C. It also had enhanced electrical properties. The measured remnant polarization (P_r) and coercive field (E_c) were 14.61 μC cm^−2 and 24.16 kV cm^−1, respectively. The P_r value was over four times greater than those of the screen-printed films. We fabricated array-type piezoelectric resonators with direct-patterned PZN–PZT thick films to show the ability of the direct-Patterning of the PZT thick film on a silicon wafer for actuator and sensor application, especially for mass production.