Osamu Tabata | Kyoto University (original) (raw)
MEMS Modelling by Osamu Tabata
… Systems, Journal of, Jan 1, 2006
Papers by Osamu Tabata
2011 6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems
ABSTRACT Configurable assembly technique of a DNA origami tile on Micro Electromechanical Systems... more ABSTRACT Configurable assembly technique of a DNA origami tile on Micro Electromechanical Systems (MEMS) using a microfluidic device to realize a Nanosystem was proposed. In this newly proposed approach, multiple DNA origami tiles fabricated by DNA origami technique are utilized as a sub-micro-scale functional building block on which nano-materials such as nano-particles and SWCNTs are assembled by DNA hybridization. This paper presents the proposed methodology and preliminary experimental results.
1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96
ABSTRACT
Japanese Journal of Applied Physics, 2021
This paper presents a microfabrication technique for vapor cells, filled with cesium (Cs), from a... more This paper presents a microfabrication technique for vapor cells, filled with cesium (Cs), from an on-chip dispensing component. Wafer-level cell fabrication with a Cs dispenser has gained considerable attention for contributing to the high performance of miniaturized atomic devices. However, the large size of the dispenser and released residual gases can be limitations to miniaturization and the stability of atomic vapor. We present a cell structure that overcomes these limitations and offers a single-mask process with typical Si-based microfabrication at the wafer level. The cell consists of an optical cavity connected to a Cs-dispensing component via microchannels. Microfabricated Si grooves with multiple re-entrant microstructures are employed for effective Cs production from cesium azide. In our experiment, Cs was successfully filled in a cell by heating at 330 °C for 10 min. The stability of the Cs atomic density in the cell was confirmed over a period of 5 months.
Proceedings 2002 IEEE International Conference on Robotics and Automation (Cat. No.02CH37292)
A new type of passive element with variable mechanical impedance is proposed. Since the proposed ... more A new type of passive element with variable mechanical impedance is proposed. Since the proposed elements are lighter, smaller and softer than the previous passive elements, these elements have the possibility to develop wearable robots. In the paper, the principles of the variable mechanical impedance are explained and the basic experimental results demonstrate the performance of the proposed element. Moreover, a wearable robot for virtual reality is developed by using the proposed element and it is shown that the developed wearable robot is utilized as a force display in the virtual world.
TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference, 2007
This paper reports a differentially detecting capacitive three-axis SOI accelerometer using novel... more This paper reports a differentially detecting capacitive three-axis SOI accelerometer using novel vertical comb electrodes. The accelerometer structure was fabricated by surface-micromachining technique and consists of only the device layer of a SOI wafer without lower or upper electrodes. The bottom faces of both movable and fixed electrodes are in the same plane at their initial positions but those heights
TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664)
ABSTRACT A new laser microfabrication technique to realize a high aspect ratio microstructure wit... more ABSTRACT A new laser microfabrication technique to realize a high aspect ratio microstructure with free shaped wall using newly developed resist was proposed. The resist is made of ethylcellulose in which nano-particles with average diameter of 3.4 nm was dispersed. Since this resist has a strong absorption at wavelength of about 530 nm, it can be processed using focused low power output Nd:YVO4-SHG laser. From the experiments, it was confirmed that the cross-sectional shape of processed resist microstructure can be controlled by the gold (Au) concentration (1-50 wt%) and the laser beam power. The processed depth showed a strong dependency on Au concentration and showed maximum at 17 wt% Au concentration. From analysis of the processed resist surface, it was revealed that the Au aggregation at the bottom of the processed channel played an important role for the resultant processed depth.
MHS2000. Proceedings of 2000 International Symposium on Micromechatronics and Human Science (Cat. No.00TH8530)
We developed a XeF2 pulse etching system controlled by a computer and examined effects of etching... more We developed a XeF2 pulse etching system controlled by a computer and examined effects of etching pressure and an aperture width on Si etching. The etching depth and the undercut ranged from 12.9 to 17.6 μm and 7.5 to 13.0 μm as the aperture width increases with a charge pressure of 390 Pa, a pulse number of 10, a pulse
The Proceedings of the Symposium on Micro-Nano Science and Technology, 2017
A new technique to control etching rates of mask materials during XeF2 etching was proposed. By e... more A new technique to control etching rates of mask materials during XeF2 etching was proposed. By exposing Si sample with SiO2 and Si3N4 as mask materials to UV light of 3 W/cm2 during XeF2 etching, the etching rates of SiO2 and Si3N4 were dramatically increased from 2.52 angstrom/pulse to 42.0 angstrom/pulse and from 27.3 angstrom/pulse to 403 angstrom/pulse, respectively. This new technique allows us to remove the mask material selectively and change the mask pattern by UV light exposure during in- situ etching process without additional photolithography step and opens a new silicon micromachining process for 3- dimensional fabrication. The multi-step Si structure was successfully realized by this technique.
These keynotes speeches the following: Nanoimaging of Cellular and Molecular Dynamics: A Paradigm... more These keynotes speeches the following: Nanoimaging of Cellular and Molecular Dynamics: A Paradigm Shift for Patient Care?; DNA as an Engineering Material to Bridge MEMS and Nanomedicine; Micro/Nano Analysis of Cell Communication and Targeted Destruction of Cancer Cells; Microfluidic Platforms for Capturing Circulating Tumor Cell; Stealth Nanotube Theranostic Agents: Shielding Carbon Nanotubes to Evade Opsonization and Improve Biodistribution; In Vitro Fertilization on a Chip for Oligozoospermia Patients; DC-powered Microfluidic Chip for Electroporation of CHO Cells; MC-1 Magnetotactic Bacteria versus Magnetic Nanoparticle-based Micro-carriers for Drug Delivery to Tumors through Capillary Networks; Micro/Nano Manipulation Enabled Cancer Cell Detection, Separation and Investigation for Personalized Medicine; Surprising Encounter between Graphitic Biomolecules/Celis; Nanoparticle Platform for Targeted Delivery of siRNA and Chemotherapies; Cancer Stem Cells and Nanomedicine; Robot-aided...
2018 IEEE Micro Electro Mechanical Systems (MEMS), 2018
We report a low-voltage and large-displacement electrostatic deformable mirror for in vivo retina... more We report a low-voltage and large-displacement electrostatic deformable mirror for in vivo retinal imaging by adaptive-optics optical coherence tomography. The mirror utilizes an electrostatic piston actuator which allows bottom electrodes to move vertically to keep the gap small to maintain large actuation force at low actuation voltage. An 8-mm-diameter mirror device was fabricated from two components; the mirror part and the actuator part. The parts were assembled with 7-μm-gap defined by an SU-8 layer. We successfully demonstrated operation of the mirror in various Zernike modes.
TRANSDUCERS '91: 1991 International Conference on Solid-State Sensors and Actuators. Digest of Technical Papers
Detailed characteristics of tetramethyl ammoniumhydroxide, (CH3)4NOH, as silicon anisotropic etch... more Detailed characteristics of tetramethyl ammoniumhydroxide, (CH3)4NOH, as silicon anisotropic etching solutions with various concentrations from 5 to 40 wt.% have been studied. The etch rates of (100) and (111) crystal planes decreased with increasing concentration. The etched (100) planes were covered by pyramidal-shaped hillocks below 15wt.%, but very smooth surfaces were obtained above 22 wt.%. The etch rate of 1.0
Sensors and Materials, 2018
A parallel testing method has been proposed with integrated strain gauges based on the piezoresis... more A parallel testing method has been proposed with integrated strain gauges based on the piezoresistive effect to shorten the testing time for investigating tensile-mode fatigue characteristics of single-crystal silicon (SCS). The method allows a high loading frequency (~110 Hz) owing to the high stiffness of the testing system and reduces the testing time per specimen by parallelization. Five specimens were integrated on a testing chip and subjected to a pulling force simultaneously using a piezoelectric actuator. The parallel portion of the specimen was 2.5 µm wide, 22 µm thick, and 120 µm long. The strain gauge connected to each gauge part consisted of an array of five straight beams 100 µm in length and 2.5 µm in width. The oneactive-gauge bridge was used and three reference registers of identical shape were also placed in series on the chip. The strain gauges successfully monitored the force on each specimen with sufficiently low noise for testing. The five specimens on the chip fractured at the same time, showing a tensile strength of 1.5 GPa. Because of the finite stiffness of the test system, there is coupling between the integrated specimens. However, the total displacement during parallel testing was sufficiently small (~15 µm) such that the system has the potential to operate with a loading frequency of 110 Hz for fatigue testing.
Nucleic Acids Research, 2018
DNA nick can be used as a design motif in programming the shape and reconfigurable deformation of... more DNA nick can be used as a design motif in programming the shape and reconfigurable deformation of synthetic DNA nanostructures, but its mechanical properties have rarely been systematically characterized at the level of base sequences. Here, we investigated sequence-dependent mechanical properties of DNA nicks through molecular dynamics simulation for a comprehensive set of distinct DNA oligomers constructed using all possible base-pair steps with and without a nick. We found that torsional rigidity was reduced by 28-82% at the nick depending on its sequence and location although bending and stretching rigidities remained similar to those of regular base-pair steps. No significant effect of a nick on mechanically coupled deformation such as the twist-stretch coupling was observed. These results suggest that the primary structural role of nick is the relaxation of torsional constraint by backbones known to be responsible for relatively high torsional rigidity of DNA. Moreover, we experimentally demonstrated the usefulness of quantified nick properties in self-assembling DNA nanostructure design by constructing twisted DNA origami structures to show that sequence design of nicks successfully controls the twist angle of structures. Our study illustrates the importance as well as the opportunities of considering sequence-dependent properties in structural DNA nanotechnology.
The Proceedings of the Materials and Mechanics Conference, 2015
The Proceedings of the Dynamics & Design Conference, 2012
IEEJ Transactions on Sensors and Micromachines, 2012
ABSTRACT In this paper, we report on a method to assemble and clamp single walled carbon nanotube... more ABSTRACT In this paper, we report on a method to assemble and clamp single walled carbon nanotubes (SWCNTs) mechanically and electrically on patterned electrodes for developing a new tensile testing method which achieves SWCNT mechanical characterization with high throughput. Electrical transport measurement on assembled SWCNTs was conducted in order to characterize clamping property. Theoretical analysis based on the obtained result reveals that the proposed mechanical clamp is sufficiently strong to conduct tensile testing of SWCNT.
The Journal of Physical Chemistry B, 2017
A new coarse-grained molecular dynamics double-stranded DNA model (nCG-dsDNA model) using an impr... more A new coarse-grained molecular dynamics double-stranded DNA model (nCG-dsDNA model) using an improved beads-spring model was proposed. In this model, nucleotide comprising phosphate, sugar, and base group were replaced by a single bead. The double stranded model with 202 base pairs was created to tune the parameters of the bond, the non-bond, stack, angle bending, and electrostatic interaction. The average twisted angle and the persistence length of the model without electrostatic interaction were calculated at 35.3° and 120.3 bp, confirming that the proposed model successfully realized the experimentally observed double-stranded DNA structure. Moreover, the model with electrostatic interaction was discussed. From calculation results, we confirmed that the dependency of the salt concentration on the persistence length of the nCG-dsDNA model at the 30% charge is in good agreement with the Poisson-Boltzmann theoretical model.
2011 6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems
ABSTRACT Configurable assembly technique of a DNA origami tile on Micro Electromechanical Systems... more ABSTRACT Configurable assembly technique of a DNA origami tile on Micro Electromechanical Systems (MEMS) using a microfluidic device to realize a Nanosystem was proposed. In this newly proposed approach, multiple DNA origami tiles fabricated by DNA origami technique are utilized as a sub-micro-scale functional building block on which nano-materials such as nano-particles and SWCNTs are assembled by DNA hybridization. This paper presents the proposed methodology and preliminary experimental results.
1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96
ABSTRACT
Japanese Journal of Applied Physics, 2021
This paper presents a microfabrication technique for vapor cells, filled with cesium (Cs), from a... more This paper presents a microfabrication technique for vapor cells, filled with cesium (Cs), from an on-chip dispensing component. Wafer-level cell fabrication with a Cs dispenser has gained considerable attention for contributing to the high performance of miniaturized atomic devices. However, the large size of the dispenser and released residual gases can be limitations to miniaturization and the stability of atomic vapor. We present a cell structure that overcomes these limitations and offers a single-mask process with typical Si-based microfabrication at the wafer level. The cell consists of an optical cavity connected to a Cs-dispensing component via microchannels. Microfabricated Si grooves with multiple re-entrant microstructures are employed for effective Cs production from cesium azide. In our experiment, Cs was successfully filled in a cell by heating at 330 °C for 10 min. The stability of the Cs atomic density in the cell was confirmed over a period of 5 months.
Proceedings 2002 IEEE International Conference on Robotics and Automation (Cat. No.02CH37292)
A new type of passive element with variable mechanical impedance is proposed. Since the proposed ... more A new type of passive element with variable mechanical impedance is proposed. Since the proposed elements are lighter, smaller and softer than the previous passive elements, these elements have the possibility to develop wearable robots. In the paper, the principles of the variable mechanical impedance are explained and the basic experimental results demonstrate the performance of the proposed element. Moreover, a wearable robot for virtual reality is developed by using the proposed element and it is shown that the developed wearable robot is utilized as a force display in the virtual world.
TRANSDUCERS 2007 - 2007 International Solid-State Sensors, Actuators and Microsystems Conference, 2007
This paper reports a differentially detecting capacitive three-axis SOI accelerometer using novel... more This paper reports a differentially detecting capacitive three-axis SOI accelerometer using novel vertical comb electrodes. The accelerometer structure was fabricated by surface-micromachining technique and consists of only the device layer of a SOI wafer without lower or upper electrodes. The bottom faces of both movable and fixed electrodes are in the same plane at their initial positions but those heights
TRANSDUCERS '03. 12th International Conference on Solid-State Sensors, Actuators and Microsystems. Digest of Technical Papers (Cat. No.03TH8664)
ABSTRACT A new laser microfabrication technique to realize a high aspect ratio microstructure wit... more ABSTRACT A new laser microfabrication technique to realize a high aspect ratio microstructure with free shaped wall using newly developed resist was proposed. The resist is made of ethylcellulose in which nano-particles with average diameter of 3.4 nm was dispersed. Since this resist has a strong absorption at wavelength of about 530 nm, it can be processed using focused low power output Nd:YVO4-SHG laser. From the experiments, it was confirmed that the cross-sectional shape of processed resist microstructure can be controlled by the gold (Au) concentration (1-50 wt%) and the laser beam power. The processed depth showed a strong dependency on Au concentration and showed maximum at 17 wt% Au concentration. From analysis of the processed resist surface, it was revealed that the Au aggregation at the bottom of the processed channel played an important role for the resultant processed depth.
MHS2000. Proceedings of 2000 International Symposium on Micromechatronics and Human Science (Cat. No.00TH8530)
We developed a XeF2 pulse etching system controlled by a computer and examined effects of etching... more We developed a XeF2 pulse etching system controlled by a computer and examined effects of etching pressure and an aperture width on Si etching. The etching depth and the undercut ranged from 12.9 to 17.6 μm and 7.5 to 13.0 μm as the aperture width increases with a charge pressure of 390 Pa, a pulse number of 10, a pulse
The Proceedings of the Symposium on Micro-Nano Science and Technology, 2017
A new technique to control etching rates of mask materials during XeF2 etching was proposed. By e... more A new technique to control etching rates of mask materials during XeF2 etching was proposed. By exposing Si sample with SiO2 and Si3N4 as mask materials to UV light of 3 W/cm2 during XeF2 etching, the etching rates of SiO2 and Si3N4 were dramatically increased from 2.52 angstrom/pulse to 42.0 angstrom/pulse and from 27.3 angstrom/pulse to 403 angstrom/pulse, respectively. This new technique allows us to remove the mask material selectively and change the mask pattern by UV light exposure during in- situ etching process without additional photolithography step and opens a new silicon micromachining process for 3- dimensional fabrication. The multi-step Si structure was successfully realized by this technique.
These keynotes speeches the following: Nanoimaging of Cellular and Molecular Dynamics: A Paradigm... more These keynotes speeches the following: Nanoimaging of Cellular and Molecular Dynamics: A Paradigm Shift for Patient Care?; DNA as an Engineering Material to Bridge MEMS and Nanomedicine; Micro/Nano Analysis of Cell Communication and Targeted Destruction of Cancer Cells; Microfluidic Platforms for Capturing Circulating Tumor Cell; Stealth Nanotube Theranostic Agents: Shielding Carbon Nanotubes to Evade Opsonization and Improve Biodistribution; In Vitro Fertilization on a Chip for Oligozoospermia Patients; DC-powered Microfluidic Chip for Electroporation of CHO Cells; MC-1 Magnetotactic Bacteria versus Magnetic Nanoparticle-based Micro-carriers for Drug Delivery to Tumors through Capillary Networks; Micro/Nano Manipulation Enabled Cancer Cell Detection, Separation and Investigation for Personalized Medicine; Surprising Encounter between Graphitic Biomolecules/Celis; Nanoparticle Platform for Targeted Delivery of siRNA and Chemotherapies; Cancer Stem Cells and Nanomedicine; Robot-aided...
2018 IEEE Micro Electro Mechanical Systems (MEMS), 2018
We report a low-voltage and large-displacement electrostatic deformable mirror for in vivo retina... more We report a low-voltage and large-displacement electrostatic deformable mirror for in vivo retinal imaging by adaptive-optics optical coherence tomography. The mirror utilizes an electrostatic piston actuator which allows bottom electrodes to move vertically to keep the gap small to maintain large actuation force at low actuation voltage. An 8-mm-diameter mirror device was fabricated from two components; the mirror part and the actuator part. The parts were assembled with 7-μm-gap defined by an SU-8 layer. We successfully demonstrated operation of the mirror in various Zernike modes.
TRANSDUCERS '91: 1991 International Conference on Solid-State Sensors and Actuators. Digest of Technical Papers
Detailed characteristics of tetramethyl ammoniumhydroxide, (CH3)4NOH, as silicon anisotropic etch... more Detailed characteristics of tetramethyl ammoniumhydroxide, (CH3)4NOH, as silicon anisotropic etching solutions with various concentrations from 5 to 40 wt.% have been studied. The etch rates of (100) and (111) crystal planes decreased with increasing concentration. The etched (100) planes were covered by pyramidal-shaped hillocks below 15wt.%, but very smooth surfaces were obtained above 22 wt.%. The etch rate of 1.0
Sensors and Materials, 2018
A parallel testing method has been proposed with integrated strain gauges based on the piezoresis... more A parallel testing method has been proposed with integrated strain gauges based on the piezoresistive effect to shorten the testing time for investigating tensile-mode fatigue characteristics of single-crystal silicon (SCS). The method allows a high loading frequency (~110 Hz) owing to the high stiffness of the testing system and reduces the testing time per specimen by parallelization. Five specimens were integrated on a testing chip and subjected to a pulling force simultaneously using a piezoelectric actuator. The parallel portion of the specimen was 2.5 µm wide, 22 µm thick, and 120 µm long. The strain gauge connected to each gauge part consisted of an array of five straight beams 100 µm in length and 2.5 µm in width. The oneactive-gauge bridge was used and three reference registers of identical shape were also placed in series on the chip. The strain gauges successfully monitored the force on each specimen with sufficiently low noise for testing. The five specimens on the chip fractured at the same time, showing a tensile strength of 1.5 GPa. Because of the finite stiffness of the test system, there is coupling between the integrated specimens. However, the total displacement during parallel testing was sufficiently small (~15 µm) such that the system has the potential to operate with a loading frequency of 110 Hz for fatigue testing.
Nucleic Acids Research, 2018
DNA nick can be used as a design motif in programming the shape and reconfigurable deformation of... more DNA nick can be used as a design motif in programming the shape and reconfigurable deformation of synthetic DNA nanostructures, but its mechanical properties have rarely been systematically characterized at the level of base sequences. Here, we investigated sequence-dependent mechanical properties of DNA nicks through molecular dynamics simulation for a comprehensive set of distinct DNA oligomers constructed using all possible base-pair steps with and without a nick. We found that torsional rigidity was reduced by 28-82% at the nick depending on its sequence and location although bending and stretching rigidities remained similar to those of regular base-pair steps. No significant effect of a nick on mechanically coupled deformation such as the twist-stretch coupling was observed. These results suggest that the primary structural role of nick is the relaxation of torsional constraint by backbones known to be responsible for relatively high torsional rigidity of DNA. Moreover, we experimentally demonstrated the usefulness of quantified nick properties in self-assembling DNA nanostructure design by constructing twisted DNA origami structures to show that sequence design of nicks successfully controls the twist angle of structures. Our study illustrates the importance as well as the opportunities of considering sequence-dependent properties in structural DNA nanotechnology.
The Proceedings of the Materials and Mechanics Conference, 2015
The Proceedings of the Dynamics & Design Conference, 2012
IEEJ Transactions on Sensors and Micromachines, 2012
ABSTRACT In this paper, we report on a method to assemble and clamp single walled carbon nanotube... more ABSTRACT In this paper, we report on a method to assemble and clamp single walled carbon nanotubes (SWCNTs) mechanically and electrically on patterned electrodes for developing a new tensile testing method which achieves SWCNT mechanical characterization with high throughput. Electrical transport measurement on assembled SWCNTs was conducted in order to characterize clamping property. Theoretical analysis based on the obtained result reveals that the proposed mechanical clamp is sufficiently strong to conduct tensile testing of SWCNT.
The Journal of Physical Chemistry B, 2017
A new coarse-grained molecular dynamics double-stranded DNA model (nCG-dsDNA model) using an impr... more A new coarse-grained molecular dynamics double-stranded DNA model (nCG-dsDNA model) using an improved beads-spring model was proposed. In this model, nucleotide comprising phosphate, sugar, and base group were replaced by a single bead. The double stranded model with 202 base pairs was created to tune the parameters of the bond, the non-bond, stack, angle bending, and electrostatic interaction. The average twisted angle and the persistence length of the model without electrostatic interaction were calculated at 35.3° and 120.3 bp, confirming that the proposed model successfully realized the experimentally observed double-stranded DNA structure. Moreover, the model with electrostatic interaction was discussed. From calculation results, we confirmed that the dependency of the salt concentration on the persistence length of the nCG-dsDNA model at the 30% charge is in good agreement with the Poisson-Boltzmann theoretical model.
IEEJ Transactions on Sensors and Micromachines, 2010
In this paper, we report on a component modeling of in-plane 2DOF comb transducer for equivalent ... more In this paper, we report on a component modeling of in-plane 2DOF comb transducer for equivalent circuit analysis of electrostatic MEMS. The proposed model does not depend on connected components such as voltage sources, external forces, and springs since the model contained a dummy spring that can detect the comb displacement in itself. Using the model, we can analyze not
Following on from the first AMN volume, this handy reference and textbook examines the topic of n... more Following on from the first AMN volume, this handy reference and textbook examines the topic of nanosystem design in further detail. It explains the physical and chemical basics behind the design and fabrication of nanodevices, covering all important, recent advances in the field, while introducing nanosystems to less experienced readers. The result is an important source for a fast, accurate overview of the state of the art of nanosystem realization, summarizing further important literature.
Covering technological aspects as well as the suitability and applicability of various kinds of u... more Covering technological aspects as well as the suitability and applicability of various kinds of uses, this handbook shows optimization strategies, techniques and assembly pathways to achieve the combination of complex, even three-dimensional structures with simple manufacturing steps. The authors provide information on markets, commercialization opportunities and aspects of mass or large-scale production as well as design tools, experimental techniques, novel materials, and ideas for future improvements. Not only do they weigh up cost versus quantity, they also consider CMOS and LIGA strategies. Of interest to physicists, electronics engineers, materials scientists, institutional and industrial libraries as well as graduate students of the relevant disciplines.