Ikuko S. Ishikawa
RIKEN Brain Science Institute
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Publication
Featured researches published by Ikuko S. Ishikawa.
Proceedings of SPIE, the International Society for Optical Engineering | 2008
T. Goji Etoh; Cuong Vo Le; Hiroyuki Kawano; Ikuko S. Ishikawa; Atshushi Miyawaki; V. T. S. Dao; H. D. Nguyen; Sayoko Yokoi; Shigeru Yoshida; Hitoshi Nakano; Kohsei Takehara; Yoshiharu Saito
We are developing an ultra-high-sensitivity and ultra-high-speed imaging system for bioscience, mainly for imaging of microbes with visible light and cells with fluorescence emission. Scarcity of photons is the most serious problem in applications of high-speed imaging to the scientific field. To overcome the problem, the system integrates new technologies consisting of (1) an ultra-high-speed video camera with sub-ten-photon sensitivity with the frame rate of more than 1 mega frames per second, (2) a microscope with highly efficient use of light applicable to various unstained and fluorescence cell observations, and (3) very powerful long-pulse-strobe Xenon lights and lasers for microscopes. Various auxiliary technologies to support utilization of the system are also being developed. One example of them is an efficient video trigger system, which detects a weak signal of a sudden change in a frame under ultra-high-speed imaging by canceling high-frequency fluctuation of illumination light. This paper outlines the system with its preliminary evaluation results.
Smart Nano-Micro Materials and Devices | 2011
Koji Sugioka; Yasutaka Hanada; Katsumi Midorikawa; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki
We demonstrate to fabricate microfluidic chips integrated with some functional microcomponents such as optical attenuators and optical waveguides by femtosecond laser direct writing for understanding phenomena and functions of microorganisms. Femtosecond laser irradiation followed by annealing and wet etching in dilute hydrofluoric acid solution resulted in fabrication of three-dimensional microfludic structures embedded in a photosensitive glass. The embedded microfludic structures enabled us to easily and efficiently observe Phormidium gliding to the seedling root, which accelerates growth of the vegetable. In addition, integration of optical attenuators and optical waveguides into the microfluidic structures clarified the mechanism of the gliding movement of Phormidium. We termed such integrated microchips nanoaquariums, realizing the highly efficient and functional observation and analysis of various microorganisms.
Pacific Rim Laser Damage Symposium: Optical Materials for High Power Lasers | 2011
Koji Sugioka; Yasutaka Hanada; Katsumi Midorikawa; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki
We demonstrate three-dimensional (3D) microstructuring inside glass by ultrafast laser to fabricate microfluidic chips integrated with some functional microcomponents such as optical attenuators and optical waveguides. The fabricated microchips are applied to understand phenomena and functions of microorganisms and cyanobacteria. Ultrafast laser irradiation followed by thermal treatment and wet etching in dilute hydrofluoric acid solution resulted in fabrication of 3D microfludic structures embedded in a photosensitive glass. The embedded microfludic structures enabled us to easily and efficiently observe Phormidium gliding to the seedling root, which accelerates growth of the vegetable. In addition, integration of optical attenuators and optical waveguides into the microfluidic structures clarified the mechanism of the gliding movement of Phormidium. We termed such integrated microchips nanoaquariums, realizing the highly efficient and functional observation and analysis of various microorganisms.
Proceedings of SPIE | 2010
Yasutaka Hanada; Koji Sugioka; Ikuko S. Ishikawa; Hiroyuki Kawano; Atsushi Miyawaki; Katsumi Midorikawa
We demonstrate fabrication of microfluidic chips integrated with different functional elements such as optical filters and optical waveguide for mechanism study of gliding movement of Phormidium to a seedling root using a femtosecond (fs) laser. Fs laser direct writing followed by annealing and successive wet etching in dilute hydrofluoric (HF) acid solution resulted in formation of three dimensional (3D) hollow microstructures embedded in a photostructurable glass. The embedded microfludic structures enabled us to easily and efficiently observe Phormidium gliding to the seedling root, which accelerates growth of the seedling. In addition, fabrication of optical filter and optical waveguide integrated with the microfluidic structures in the microchip clarified the mechanism of the gliding movement. Such microchips, referred to as a nano-aquarium, realize the efficient and highly functional observation and analysis of the gliding movement of Phormidium.
Pacific International Conference on Applications of Lasers and Optics | 2010
Koji Sugioka; Yasutaka Hanada; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki; Katsumi Midorikawa
Internal modification of transparent materials such as glass can be carried out using multiphoton absorption induced by a femtosecond (fs) laser. The fs-laser modification followed by thermal treatment and successive chemical wet etching in a hydrofluoric (HF) acid solution forms three-dimensional (3D) hollow microstructures embedded in photosensitive glass. This technique is a powerful method for directly fabricating 3D microfludic structures integrated with some functional microcomponents inside a photosensitive glass microchip. We used the fabricated microchips, referred to as a nanoaquarium, for dynamic observations of living microorganisms. In this paper, among some examples, we focus on exploring mechanism of Phormidium assemblage to seedling root for growth promotion of vegetable using the nanoaquarium.Internal modification of transparent materials such as glass can be carried out using multiphoton absorption induced by a femtosecond (fs) laser. The fs-laser modification followed by thermal treatment and successive chemical wet etching in a hydrofluoric (HF) acid solution forms three-dimensional (3D) hollow microstructures embedded in photosensitive glass. This technique is a powerful method for directly fabricating 3D microfludic structures integrated with some functional microcomponents inside a photosensitive glass microchip. We used the fabricated microchips, referred to as a nanoaquarium, for dynamic observations of living microorganisms. In this paper, among some examples, we focus on exploring mechanism of Phormidium assemblage to seedling root for growth promotion of vegetable using the nanoaquarium.
INTERNATIONAL SYMPOSIUM ON HIGH POWER LASER ABLATION 2010 | 2010
Koji Sugioka; Yasutaka Hanada; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki; Katsumi Midorikawa
We demonstrate to fabricate microfluidic chips integrated with some functional elements such as optical attenuators and optical waveguides by femtosecond (fs) laser direct writing for mechanism study of gliding movement of Phormidium to a seedling root. Femtosecond laser irradiation followed by annealing and wet etching in dilute hydrofluoric (HF) acid solution resulted in formation of three‐dimensional (3D) hollow microstructures embedded in a photosensitive glass. The embedded microfludic structures enabled us to easily and efficiently observe Phormidium gliding to the seedling root, which accelerates growth of the vegetable seedling. In addition, integration of optical attenuators and optical waveguides into the microfluidic structures in the microchip clarified the mechanism of the gliding movement of Phormidium. Such microchips, referred to as nanoaquariums, realized the highly efficient and functional observation and analysis of various microorganisms.
Proceedings of SPIE | 2008
Yasutaka Hanada; Koji Sugioka; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki; Katsumi Midorikawa
We demonstrate the fabrication of three-dimensional (3-D) hollow microstructures embedded in photostructurable glass by a femtosecond (fs) laser direct writing. Fs laser direct writing followed by annealing and successive wet etching in dilute hydrofluoric (HF) acid solution resulted in the rapid manufacturing of microchips with 3-D hollow microstructures for the dynamic observation of living microorganisms in fresh water. The embedded microchannel structure enables us to analyze the continuous motion of Euglena gracilis. A microchamber with a movable microneedle demonstrates its ability for the elucidation of the information transmission process in Pleurosira laevis. Such microchips, referred to as nano-aquariums realize the efficient and highly functional observation of microorganisms.
Photonics and Optoelectronics Meetings (POEM) 2008: Laser Technology and Applications | 2008
Yasutaka Hanada; Koji Sugioka; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki; Katsumi Midorikawa
We demonstrate the fabrication of three-dimensional (3D) hollow microstructures embedded in photostructurable glass by a nonlinear multiphoton absorption process using a femtosecond (fs) laser. Fs laser direct writing followed by annealing and successive wet etching in dilute hydrofluoric (HF) acid solution resulted in the rapid manufacturing of microchips with 3-D hollow microstructures for the dynamic observation of living microorganisms in fresh water. The embedded microchannel structure enables us to analyze the continuous motion of Euglena gracilis and Cryptomonas. Such microchips, referred to as nano-aquariums realize the efficient and highly functional observation of microorganisms.
Microfluidics, BioMEMS, and Medical Microsystems VI | 2008
Yasutaka Hanada; Koji Sugioka; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki; Katsumi Midorikawa
We demonstrate the fabrication of three-dimensional (3D) hollow microstructures embedded in photostructurable glass by a nonlinear multiphoton absorption process using a femtosecond (fs) laser. Fs laser direct writing followed by annealing and successive wet etching in dilute hydrofluoric (HF) acid solution resulted in the rapid manufacturing of microchips with 3-D hollow microstructures for the dynamic observation of living microorganisms in fresh water. The embedded microchannel structure enables us to analyze the continuous motion of Euglena gracilis and Dinoflagellate. Such microchips, referred to as nano-aquariums realize the efficient and highly functional observation of microorganisms.
Biomedical Microdevices | 2008
Yasutaka Hanada; Koji Sugioka; Hiroyuki Kawano; Ikuko S. Ishikawa; Atsushi Miyawaki; Katsumi Midorikawa