A nanopipette ball probe for dimensional measurement of micro-structures

So Ito,Issei Kodama,Wei Gao 한국생산제조학회 2012 한국생산제조시스템학회 학술발표대회 논문집 Vol.2012 No.10

The measurement system using a nanopipette ball probe is introduced for dimensional measurement of micrometer-scale structures. The nanopipette ball probe is consisted of thermally pulled capillary glass tube, and then a glass micro sphere with 9 μm diameter is attached at the edge of the capillary glass tube. In order to measure the distance between the edge of the probe and the surface of the measuring object, a method of shear-force detection is employed in this study. Since the shear-force detection can detect an interaction due to a water layer on the surface of the measuring object, it will be able to achieve non-contact measurement of the microstructures. During the measurement, the nanopipette ball probe is oscillated in lateral direction on its resonance frequency. The nanopipette ball probe can be detected the approaching from three axial direction by using single sensor. This paper presents the experimental investigations for performance evaluation of the nanopipette ball probe as a measurement system for dimensional measurements.

Construction and Verification of a Linear-rotary Microstage with a Millimeter-scale Range

Yuxin Peng,So Ito,Yasumasa Sakurai,Yuki Shimizu,Wei Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

This paper presents a second-generation linear-rotary (Z-θZ) micro-stage driven by impact friction. The micro-stage was constructed by miniaturizing a previously developed linear-rotary stage. The moving element of the micro-stage, which was a steel cylinder, could be actuated along and around the Z-axis in millimeter-scale range. The steel cylinder was supported by two driving units. Each unit consisted of a permanent magnet and two piezoelectric actuators (PZTs) for generating the impact friction motions in the Z- and θZdirections. The size of the micro-stage was made to be 11.0 mm (L) × 11.0 mm (W) × 5.7 mm (H). For enhancement of the stage velocity, the transfer function of the micro-stage with the voltage applied to the PZT as the input and the PZT displacement as the output, was established. An improved waveform of the input voltage was then obtained based on the established transfer function for getting a triangular-shaped PZT displacement, which was an ideal waveform for the impact friction motion. The characteristics of the stage velocity before and after the improvement of the input voltage were verified and the effectiveness of the improved input voltage for enhancement of the stage velocity was confirmed.

Characterization of Electrostatic Force for Scanning Electrostatic Force Microscopy of Micro-structured Surface

Zhigang Jia,So Ito,Keiichiro Hosobuchi,Shigeaki Goto,Yuki Shimizu,Gaofa He,Wei Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

This paper presents the electrostatic force characterization of a prototype scanning electrostatic force microscope (SEFM) system developed for surface profile measurement in noncontact condition. In the SEFM system, with applying a dual height method, the distance between the probe tip and the sample surface can be accurately obtained by removing the influence of the electric field distribution on the sample surface. Since the electrostatic force is greatly influenced by the capacitance between the probe tip and the sample surface, a new approach for modeling and characterization of the distribution of capacitance between the probe tip with an arbitrary shape and the sample surface with a random topography by using the finite difference method (FDM) is proposed. The electrostatic forces calculated by the FDM method and the conventional sphere-plane model are compared to verify the validity of the FDM method. The frequency shift values measured by the experiment are also compared with the simulation results calculated by the FDM method. It has been demonstrated that the electrostatic force between arbitrary shapes of the probe tip and the sample surface can be well calculated by the FDM.

Fabrication of Scale Gratings for Surface Encoders by Using Laser Interference Lithography with 405 nm Laser Diodes

Xinghui Li,Yuki Shimizu,So Ito,Wei Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

This paper presents a cost-effective fabrication method of grating structures with a period of sub-μm for surface encoders. By employing an inexpensive and compact blue laser diode, which has a wavelength of 405 nm and is used in Blu-ray disc drives, a Lloyd’s mirror interferometer has been developed to carry out laser interference lithography for the fabrication of grating structures. Experimental results showed that the developed fabrication system is capable of fabricating grating structures with a pitch of 570 nm. The relative pitch deviation is confirmed to be approximately 1%, which meets the requirement for the scale grating used in a surface encoder. The influence of the limited coherence length of the laser diode on the fabrication area of the grating structures has also been investigated. To expand the fabrication area of the grating structure, a laser source, which has a wavelength of 405 nm and a longer coherence length with a mode selection cavity, is employed in the fabrication system. It has been verified by experiments that the fabrication area of the sub-μm periodic grating structures can be expanded to 300 mm2 with the laser source.

Surface Profile Measurement of Internal Micro-Structures

Bin Xu,Yuki Shimizu,So Ito,Wei Gao 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

A measurement system is presented for surface profile measurements of micro-structures generated on internal cylindrical surfaces of workpieces. The main components of the measurement system are an air-bearing spindle to rotate the measured internal microstructures,an air-bearing displacement sensor with a diamond micro-stylus probe to scan the surface profile of the internal microstructures being measured and a vibration isolation table to reduce the disturbance of the measurement environment. The stability of the air-bearing displacement sensor with a diamond micro-stylus probe was experimentally investigated. Measurements of surface profile of internal micro-structures were also carried out while employing a newly-developed algorithm to correct errors caused by the tip radius of the diamond micro-stylus.

Analysis and Measurement of the Dynamic Motions of a Large-Scale Rotating Roll Workpiece

Lee, Jung Chul,Gao, Wei,Shimizu, Yuki,Ito, So,Hwang, Jooho,Oh, Jeong Seok,Park, Chun Hong Trans Tech Publications, Ltd. 2012 Key Engineering Materials Vol.523 No.-

<P>This paper describes the analysis and measurement of the dynamic motions of a large-scale rotating roll workpiece, which is used for a large-scale lathe, under the gravity condition. A dynamic model which includes the gravity effect was first established. In order to investigate the behavior which comes from stiffness differences of the journal bearing at the headstock and the tailstock, a spring-mass-damper system was also established. In addition to the simulations, the behavior of the rotating roll workpiece was investigated with respect to the different rotating speed. In the experiment, a mirror finished hollow type roll workpiece with a diameter of 320 mm, a length of 1800 mm, a weight of about 340 kg was fabricated by a large-scale lathe. Five capacitive type displacement sensors were mounted on the sensor holders which were arranged along the axis of rotation of the spindle. The behavior measurement was carried out at 5 sections of the roll workpiece along the axial direction. The rotating speed was set to be 5, 50, 100, 150, 200, 250 and 300 rpm. The dynamic model for the analysis with simulations and the measurement result of the behavior of a rotating roll workpiece according to the different rotating speed are presented in this paper.</P>

An Ultra-precision Electronic Clinometer for Measurement of Small Inclination Angles

Tan, Siew-Leng,Kataoka, Satoshi,Ishikawa, Tatsuya,Ito, So,Shimizu, Yuuki,Chen, Yuanliu,Gao, Wei,Nakagawa, Satoshi The Korean Society of Manufacturing Technology Eng 2014 한국생산제조학회지 Vol.23 No.6

This paper describes an ultra-precision electronic clinometer, which is based on the capacitive-based fluid type, for detection of small inclination angles. The main parts of the clinometer low-noise electronics are two capacitance measurement circuits for converting the capacitances of the capacitors of the clinometer into voltages, and a differential amplifier for obtaining the difference of the capacitances, which is proportional to the input inclination angle. A 16 bit analog to digital (AD) converter is also embedded into the same circuit board, whose output is sent to a PC via RS-232C, for achieving a small noise level down to tens of ${\mu}v$. A compensation method, which is referred to as the delay time method for shortening the stabilization time of the sensor was also discussed. Experimental results have shown the possibility of achieving a measurement resolution of $0.0001^{\circ}$ as well as the quick measurement with the delay time method.

Design of a Laser Autocollimator-based Optical Sensor with a Rangefinder for Error Correction of Precision Slide Guideways

Siew Leng Tan,Yuki Shimizu,Takayuki Meguro,So Ito,Wei Gao 한국정밀공학회 2015 International Journal of Precision Engineering and Vol. No.

This paper presents the design and construction of a laser autocollimator-based optical sensor for measurement of the tilt angles ofa reflector mounted on the guideways or the moving table of a precision linear slide in the production process of the slide, wherethe measurement is repeatedly carried out together with a hand scraping operation for correction of the form errors of the slideguideways. Differing from a conventional autocollimator, a laser rangefinder unit is integrated with the autocollimation unit fordetection of the positions of the reflector, which is necessary for the efficient error correction of the slide guideways. Theautocollimation unit and the rangefinder unit share the same light source for a compact optical design. The optical power of the laserbeam is first set to be constant for tilt angles measurement. Then the optical power is modulated with a frequency of 66.7 MHz formeasuring the position/distance based on the phase shift method. The resolution of the laser autocollimator is confirmed to be 0.2arc-second over a range of ±50 arc-seconds while the measurement positions can be detected with a resolution of 1 mm by therangefinder, which satisfies the requirements from production of the slide.

An Ultra-precision Electronic Clinometer for Measurement of Small Inclination Angles

Siew?Leng Tan,Satoshi Kataoka,Tatsuya Ishikawa,So Ito,Yuuki Shimizu,Yuanliu Chen,Wei Gao,Satoshi Nakagawa 한국생산제조학회 2014 한국생산제조학회지 Vol.23 No.6

Third-line Hormonal Therapy to Treat Prostate Cancer Relapse after Initial and Second-line Hormonal Therapy: Report of 52 Cases and Literature Review

Matsumoto, Kazuhiro,Hagiwara, Masayuki,Hayakawa, Nozomi,Tanaka, Nobuyuki,Ito, Yujiro,Maeda, Takahiro,Ninomiya, Akiharu,Nagata, Hirohiko,Nakamura, So Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

The aim of this study was to evaluate the efficacy of third-line combined androgen blockade (CAB) therapy for castration-resistant prostate cancer that relapsed after primary and second-line CAB. We retrospectively reviewed the medical records of 52 patients who received first-, second-, and third-line CAB therapy (medical or surgical castration, plus steroidal antiandrogen of chlormadinone acetate, or nonsteroidal antiandrogen of flutamide or bicalutamide). For cumulative analysis, we searched the PubMed database and identified a total of 50 cases published in English. Including our cases, this provided a total of 102 cases for analysis. In our study cohort, 11 cases (21.2%) achieved more than 50% reduction of serum prostate-specific antigen (PSA) on initiation of third-line CAB. We found that third-line CAB with nonsteroidal antiandrogen after second-line CAB with steroidal antiandrogen exhibited favorable results, with a positive response in six of 13 patients (46.2%). Cumulative analysis findings were comparable. Regarding the timing of third-line CAB administration, 15 patients had started at a PSA equal to or less than 4.0 ng/ml, and eight of them (53.3%) showed a positive response to treatment, compared to only three of 37 patients (8.1%) whose PSA at the initiation of third-line therapy was higher than 4.0 ng/ml (p<0.001). We conclude that third-line CAB with nonsteroidal antiandrogen would be particularly useful for patients whose cancer progressed after second-line CAB with steroidal antiandrogen. The timing of treatment seems to be important because the higher the PSA at the start of third-line therapy, the lower the PSA response rate.