Kyushu University Academic Staff Educational and Research Activities Database
List of Presentations
Oki Yuji Last modified date:2019.04.08

Professor / Dept. of I&E Visionaries / Department of Electronics / Faculty of Information Science and Electrical Engineering


Presentations
1. Yuta Nakashima, Masaki Kounoura, Nao Watanabe, Sae Iwata, Shota Tsuru, Junfeng Zhu, Keisuke Nakakubo, Hiroyuki Ohashik , Kinichi Morita, Hiroaki Yoshioka, Yuji Oki, Satoru Kuhara, Kosuke Tashiro, Yoshitaka Nakanishi, Continuous monitoring of cell activity and culture conditions during cultivation using microplate reader with SOT spatial filter, Biosensors 2018, 2018.06, This paper presents that a 24 channel plate reader for continuous monitoring the cultured cell in real time. Continuous monitoring of the cell is very important for maintaining and controlling the cell multiplication and the cell differentiation. The fabricated 24 channel plate reader permits the real time cell monitoring during cultivation in the clean bench and cell culture condition. The presented 24 channel plate reader is consisted of a silicone optical technology (SOT) spatial filter, LED light source, and color sensors, and realized miniaturization of the almost same size as the cell culture microwell plate. We proposed SOT which can obtain excellent noise reduction effect, recently [1]. Because the light reflection at the optical path interface can be absorbed and the only straight forward light can be transmitted, it is possible to expect a larger S/N ratio compared with the conventional optical system. The SOT consists of a transparent PDMS in the optical path and a PDMS in which microsized carbon is dispersed in the light guide. We fabricated a spatial filter with SOT structure and confirmed the light absorption performance based on the presence or absence of light shielding against external light. As a result, the difference was 0.02%. By using this spatial filter, it is possible to manufacture a device which does not consider the influence of external light [2].
As a results of cell activity assay using fabricated 24 channel plate reader, cell activity that increase with time passage was successfully evaluated by the presented system..
2. Dongyang Liao, Yuya Mikami, Keisuke Nakakubo, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Development of local and portable sensor network based on silicone optical technology and open architecture
, The 7th Asia-Pacific Optical Sensors Conference (APOS), 2018.05, Portable and low-cost test bench system were developed for IoT sensing prototype. To focus on the optical image and data analysis, ThingSpeak was proposed and demonstrated on Linux server with the assistance of Mathematica. The server was downsized into the potable one board computer, and tiny sensor client on which with “silicone optical technology” were also developed and evaluated.

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3. Junfeng Zhu, Keisuke Nakakubo, Yuya Mikami, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Development of novel type transparent/scattering filter for 260 / 280 nm with simple PDMS composition
, The 7th Asia-Pacific Optical Sensors Conference (APOS), 2018.05, Novel scheme of optical wavelength filter was studied. The index matching of the scattering particles of CaF2 and matrix of polydimethylsiloxane due the different index dispersions was predicted and experimentally demonstrated around the UV wavelength region. Two kinds of the pair of the host-guest showed transparent wavelengths of 260 nm and 280 nm, and these wavelengths were useful for DNA / protein monitoring. Simple Monte-Carlo simulation was also programmed and good agreement was obtained..
4. Taku Takagishi, Hiroaki Yoshioka, Shintaro Mitsui, Yuya Mikami, Naoya Nishimura,Yuji Oki, Highly Transparent Organic Microdisk Cavity in Visible Range by the Ink-jet Printing Method, CLEO 2018, 2018.05, We experimentally demonstrated the fabrication and the fundamental lasing evaluation of a printed microdisk cavity by focusing on a fluorinated spherical polymer FZ-001 to achieve a microdisk with small absorption loss in the visible range..
5. Keisuke Nakakubo, Junfeng Zhu, Yuya Mikami,Hiroaki Nomada, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Novel spectroscopic transparent/scattering material for 260/280nm ultraviolet optical detection, CLEO 2018, 2018.05, Novel type of wavelength filter was proposed and demonstrated. Polydimethylsiloxane was mixed with CaF2 particles. This scattering material of 30wt% provided transparency at specified wavelength of 259 nm and 278nm..
6. Keisuke Nakakubo, Hiroaki Nomada, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, On-demand lens fabrication by liquid phase molding with gallium and Polydimethylsiloxane, CLEO 2018, 2018.05, A new on-demand lens fabrication with gallium molding was proposed and demonstrated. A convex and concave surface of liquid gallium is transferred to Polydimethylsiloxane. The curvature can be controlled between ±0.37 mm-1.
7. Keisuke Nakakubo, Chacriya Malasuk, Shota Tsuru, Kinichi Morita, Hiroaki Yoshioka, Yuji Oki, Multichannel Absorption Analysis based on Silicone Optical Technology quasi-spatial filter for micro-plate
, Asianalysis XIV, 2018.04, We have proposed novel optical packaging concept "Silicone Optical Technology" (SOT) in which polydimethylsiloxane (PDMS) is commonly used instead of conventional dielectrics such as glass, PMMA, and air. In this scheme, various optical functions can be integrated into a tiny volume because dispersing materials/particles/pigments can develop such functions. For example, dispersing dye (Sudan II) in PDMS is wavelength filter, and also Carbon particles (μm size) dispersed PDMS has a function as optical block [1]. In particular, PDMS optical paths covered with the carbon+PDMS layer can cut off stray light scattered from the unexpected optical incidence because there is refractive index matching (in real part) and penetrated light is absorbed in carbon particles. By using the technology, optical special filter for spectroscopy detection system can be emulated with very tiny volume. In this report, we report easy and very simple integration of an optical absorption measurement into a microplate reading with 24 wells. .
8. Junfeng Zhu, Keisuke Nakakubo, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, A compact optical system based on transparent scattering-filters in the specific UV wavelength range
, Asianalysis XIV, 2018.04, The conventional optical system is composed of various optical elements which always made by glass, metal etc. Such devices have a high accuracy, but they tend to be large and heavy. So, from the considerations of portability and cost, our research group proposed silicone optical technology (SOT), it is a compact, inexpensive, optical system construction technology that can be fabricated by imprint using PDMS. In previous studies, we fabricated the scattering filters that are transparent at 259 nm and 278 nm [1] - [3] based on the theory of " refractive index matching ". We dispersed CaF2 powder in KE103 (Shinetsu Chemical) and got the filter which is transparent at 259 nm, in the same ways, we got the 278 nm transparent filter using CaF2 & SIM360 (Shinetsu Chemical). And in this study, we will continue to focus on the wavelengths of 260 nm and 280 nm that can be used for DNA / protein measurement [2], and develop the compact absorption optical system for DNA / protein measurement. .
9. Yuji Oki, Kinichi Morita,, Development of Optical Devices and Systems based on Silicone Optical Technology for Ubiquitous and Edge-analytics, 2018 Asia Workshop on Smart Sensors and Systems (AWSSS), 2018.03.
10. "How to make almost anything" in data collection network platform for personal IoT.
11. Fabrication of self-formed laser resonators based on additive manufacturing concept.
12. Yuji Oki, Kinichi Morita, Hiroaki Yoshioka, Silicone-Optical-Technologies as rapid and easy optical prototyping for distributed sensor network and IoT, Joint workshop btw SKKU and Kyushu University, 2018.01, We have proposed Silicone optical technology(SOT) [1] that is based on polydimethylsiloxane (PDMS) as a common matrix for compact and monolithic optical system component of passive of passive devices.
Firstly, the internal scattering suppression with carbon particle dispersion[2](Figure), absorption filtering with dye molecule dispersion[2] were introduced in the compact and light weight laser fluorescence spectroscopy module. It was able to connect a green "laser pointer" module and a compact photomultiplier tube on its both optical ends without any light invasion from external background noise. The thermal conductivity was also controlled by partially dispersion of SiC particles.
As one of recent result, a metallic reflectors and self-formed spherical surface fabrication was also studied with gallium/PDMS boundary.[3,4]
Finally, novel type of optical filter based on refractive indices matching was also proposed. The CaF2/PDMS scattering material became transparent just at the specified wavelength of 260 nm and 280 nm.[5] Due to the difference of indices dispersion of PDMS and CaF2, both indices matched at a designed wavelength and net-transparency about 80~100% was obtained from 1mm thick scattering film containing 30 wt% CaF2. These wavelength is important for DNA quality diagnostic[6]..
13. 廖 冬陽,三上 裕也, 吉岡 宏晃, 森田 金市, 興 雄司, IoT指向ポータブル光計測システムとオープンソースクラウドデータ処理の開発, 第8回マイクロ・ナノ工学シンポジウム_, 2017.11, The compact IoT and data science system based on the open source platform (ThingSpeak) was proposed and demonstrated. Easy and powerful data process with Mathematica was combined by developing a triggering daemon of Python and PHP. This system also accelerate the data process speed from the Andriod terminal on a site. An IoT-like open source cloud computing platform is developed, based on ThingSpeak and focused on optical image and data analysis. Platform that give users the ability to handle the optical image and numerical data and store them in ThingSpeak by remote. .
14. 朱 峻鋒,中窪 奎喬, 吉岡 宏晃, 森田 金市, 興 雄司, フッ化物マイクロ粒子分散シリコーンによる波長選択的散乱・透過フィルター, 第8回マイクロ・ナノ工学シンポジウム_, 2017.11, Calcium fluoride micro particles are dispersed in polydimethylsiloxane as a novel optical material for ultra violet optical filter that is transparent for a specified wavelength and diffusor for the other wavelength. The specified wavelength of 259nm and 278nm were discovered by selecting PDMS product. The optical properties were investigated and discussed..
15. Junfeng Zhu, Keisuke Nakakubo, Hirokazu Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Simple and Cheap Spectroscopy System Specified for 260/280 nm using Silicone Optical Technology, ICFIA 2017, 2017.09, Recently, we proposed “Silicone Optical Technology(SOT)” [1] in which polydimethylsiloxane (PDMS) overrides any other optical matrix in an aim of compact and cheap optcal system. All-in-one PDMS black-module was developed by embeding optical components such as a light collimater, reflectors, optical traps, and color filters by doping carbon absorbers and dyes[2]. In addition, We also focued the UV tranparency of PDMS, for instance, pure PDMS may be tanparent at wavelength of 230nm. After preliminal experiment, we found that some kind of solid PDMS can keep the tranparency at wavelength of 260, 280nm that is key wavelength for DNA/protein investigation. In this report, we demonstrated very simple structure of the optical filter for 260 and 280 nm as a new component of SOT.
Developed optical filter has very simple structure such as micron-sized particle dispersed PDMS film. The particle is CaF2 ceramic, and the filme shows like white scattering film in visible region, because of refractive indices mismaching (1.41 and 1.43). However, at a wavelength in ultraviolet region, the refractive indices are matched and the film turns transparency. We demonstrated that two kind of PDMS truns transparency at 259nm and 278nm by mixing two kinds of PDMS with CaF2 powder. The Disposable micro-cell were also fabricated by using the filter film as optical windows. We also report about compact optical system using this new optical material.
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16. Keisuke Nakakubo, Junfeng Zhu, Hiroaki Nomada, Kinichi Morita, Hiroaki Yoshioka, Yuji Oki, 3D-Printed Lens Molds by Gallium Surface Control for On-Demand Fabrication of Optical Sensing System
, ICFIA 2017, 2017.09, Recently, flow-injection analysis with optical detection are using solid-state light pass such as glass, polymer, and polydimethylsiloxane (PDMS) in comparison with optical pass of space in traditional optical systems. We proposed fully solid-state optica system made of PDMS using the concept “Silicone Optical Technology(SOT)” [1]. PDMS matrix can provide embedded optical components such as a light collimater, reflectors, optical traps, and color filters by doping carbon absorbers and dyes[2]. We also propose novel scheme of optical surface molding for lenses by using gallium / PDMS boundary, but concave surface of solid-gallium could not obtained due to the gallum extension under the solidification. [3]
We report about improved fabrication using a mechanism of the surface formation using our new “push-pull injection method” for gallium mold fabrication. The super-cooled liquid gallium’s (below 25℃) contact angle showed strong histerisys and liquid-liquid boundary can keep the clear optical surface even though the convex focus of PDMS was successfully fabricated. Since the capilary length of gallium/PDMS contact is 3.5mm, the maximum lens diameter was estimated as 7.0mm. The shortest focal length of 6.6 mm was demonstrated with lens diameter of 5mm. The grating surface also imprinted by using PDMS/Gallium bounday molding. It found that no residual gallium was found after lifting-off PDMS surface.
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17. Ryoichi Ishimatsu, Kinichi Morita, Yuji Oki, Toshihiko Imato, Applications of a Portable UV-Vis Spectrometer for Enzymatic Reactions, ICFIA 2017, 2017.09, Portable devices are spreading in the field of analytical sciences, and they change the way of experiments and collecting data. In laboratories, we use large facilities to obtain experimental results such as chemiluminescence, fluorescent, and light absorption changes for the determination of analytes. Nowadays, such light intensity changes can be acquired by using portable devices easily. The miniaturization of Lab-equipped large detection-systems facilitates, which are usually low cost, may enable us to have own device. We believe that the portable detection system linked with smart phones as a gateway of internet of things (IoT) will be a standard system in the near future not only in laboratories but also in everywhere.
Here, we demonstrate some applications of enzymatic reactions using a portable UV-Vis absorption detection device, which can control with a tablet PC through a Bluetooth connection. Proposing applications for the detection system with IoT are very important for convenient and in-situ analysis. Enzymatic reactions are useful because of their sensitive and selective response against analytes, and applicable for the wireless detection system. As an example, we discuss the detection of -glutamyl transpeptidase (-GTP), which found in the liver and catalyzes the transfer of glutathion. The capability of enzyme-linked immunosorbent assays using the portable device will also be discussed..
18. Naho Watanabea , Sae Iwata, Masaki Kounoura, Yuta Nakashima ,Hiroyuki Ohashi , Kinichi Moritad , Yuji Oki , Satoru Kuharaa , Kosuke Tashiro , Evaluation on the Effect of Titanium Substrate Surface Irradiated with Vacuum Ultraviolet Light on Cultivation of Fibroblast and its Difference, ICFIA 2017, 2017.09, This study indicates the influence of titanium (Ti) surface state on cellular proliferation/differentiation/activation. It is well known that the photofunctionalization by ultraviolet (UV) irradiation to Ti substrate markedly promotes the osteogenesis. Photofunctionalization is surface processing technique for improving implant surfaces such as orthopedic / prosthetic-implant by luminous rays having specific wavelength and designated strength. The adhesiveness and function expression of cells are considered to influence by the surface state (hydrophilic, hydrophobic, roughness, etc.) of substrate materials. It is common knowledge that cells strongly adhere to a UV irradiated Ti substrate because affinity of Ti surface and cells is improved by UV surface modification. However, details of these phenomenon and mechanisms are not clarify. In this study, the influence of surface modification of Ti substrates by UV irradiation to cells was examined based on method of physical chemistry and biochemistry such as immune assay, gene expression analysis, and fluorescent observation. The pure Ti substrates with surface roughness of 0.1 μm was used as experimental samples. The 172nm excimer lamp was used for photofunctionalization process of Ti substrates. Also, ozone treatment of Ti substrate was carried out for comparison examination. The osteoblast cells (MC3T3) and the myoblast cells (C2C12) were used for evaluating the photofunctionalization effect of the Ti substrate. We would like to discuss the relationship between the physicochemcal state of Ti surface and proliferation, differentiation, and activation of cultured cells..
19. Keisuke Nakakubo, Zhu JunFeng, Kinichi Morita , Hiroaki Yoshioka, Yuji Oki, Open Window Flow-in Type Chamber for Fluorescence Detection using Silicone Optical Technology, ICFIA 2017, 2017.09, Recently, we proposed “Silicone Optical Technology(SOT)”, [1] in which polydimethyl-siloxane (PDMS) is common matrix for light path and micron-sized carbon dispersed PDMS (C-PDMS) can be combined to suppress the internal scattering. A light core channel of transparent PDMS with C-PDMS clad works as a simple spatial filter, that can pass only ray along to the axis of the core. [2] By using the straight spacial filter, the optical clump meter was also proposed and demonstrated. In this report, the bundled spatial filter was inserted between the photo detector (Hamamatsu, H10721) and to improve S/N raito even though the open-window fluorescence detection chamber.From the simple calculation about scattered light from open-window, the noise intensity is approximately propertial to (d/L)^3 , where d and L are the core diameter and the length of the straight spatial filter, respectively. So, the S/N ratio is proportional to the L/d, if the large apartured if the spatial filter was replaced with bundles spatial filters. As a demonstration long sized swab stick tester was developed without cap. 5 spatical filters (1mm diam. 5mm length) are bundled for above coupling. As a result of the simulation, the fluorescence signal obtained by the 5 bundled spatial filter has a signal down to 40%, suppressed the background noise to 95% or less, as compared with the fluorescence signal obtained with the optical path(12mm diam. 5mm length) in the open window, and it was calculated that the SN ratio can be improved by 10 times or more. In this research we will discuss the results of comparison with measured values..
20. 水流章太, 中窪奎喬, 吉岡宏晃, 森田金市, 興雄司, シリコーン空間光フィルタを利用した開放型吸光計測系の開発, 平成29年度(第70回)電気・情報関係学会九州支部連合大会, 2017.09.
21. 高岸 拓, 三井辰太郎, 三上裕也, 吉岡宏晃, 西村直也興 雄司, 印刷技法によるフッ素系球状ポリマーのマイクロディスク共振器の作製とその評価
, 平成29年度(第70回)電気・情報関係学会九州支部連合大会, 2017.09.
22. 三井 晨太郎, 吉岡 宏晃, 三上 裕也, 興 雄司, インクジェット印刷法による酸化亜鉛マイクロディスク共振器の作製, 応用物理学会秋季学術講演会, 2017.09.
23. 朱 峻鋒, 樋口 宏和, 吉岡 宏晃, 森田 金市. 興 雄司, 特定波長で透明な散乱フィルターによるDNA検査に向けた小型吸光光学系の開発, 応用物理学会秋季学術講演会, 2017.09, 我々はポリジメチルシロキサン(PDMS)を積極的に利用した小型、安価でインプリント作製可能な光学技術SOT(Silicone Optical Technology)を提案し、オンデマンド・オンサイト製造を提供可能な一体形光学系の基盤技術について研究を行っている。今回はDNA試料評価に利用できる260 nm, 280 nmの波長に着目し、分光的機構を持つ新しい方式での紫外透過型散乱体の開発について報告する。.
24. Keisuke Nakakubo, Hiroaki Nomada, Hiroaki Yoshioka, Kinichi Morita , Yuji Oki, Liquid phase imprinting on Gallium/PDMS boundary for on-demand lens fabrication , EOSMOS 2017, 2017.06, On-demand and print-like fabrication of optical components was proposed. Liquid Ga injection and its “push-pull” process provided positive and negative meniscus. Solid Ga mold for concave, and liquid Ga mold for convex were successfully fabricated, and the fabricated PDMS lens were evaluated..
25. Harunobu Takeda, Cong Chen, Takeshi Komino, Hiroaki Yoshioka, Yuji Oki, Chihaya Adachi, THz absorption measurement and calculation of organic thermally activated delayed fluorescence materials, CLEO/Europe 2017, 2017.06.
26. Cong Chen, Jifeng Li, Shintaro Mitsui, Soichiro Ryu, Yuya Mikami, Naoya Nishimura, Hiroaki Yoshioka, Yuji Oki, Investigation of protein adsorption for biosensors based on ink-jet printed active microdisk resonator, CLEO/Europe 2017, 2017.06, Summary form only given. Whispering Gallery Modes (WGMs) resonator based biosensors have received much attention due to the advantages of small volume, high sensitivity and label-free. Such sensors can be assigned into passive resonator sensor [1] and active resonator sensor. Different with passive resonator sensor, active resonator based sensor [2] is potential because there are (i) no need an expensive tuneable laser as source; (ii) no need a waveguide or a tapered fiber to couple evanescent field; (iii) no need a nanopositioner for adjusting coupling distance. However, as one of active resonator's drawbacks, the limited lifetime of lasing determined by organic dye should be considered. In order to solve this problem, many researchers use renewable gain material to reproduce active resonators. Such renewable devices usually based on a liquid system. For solid-state sensing system, another scheme is to use a disposable resonator. To achieve such a resonator, a low-cost, on-demand, rapid fabrication method is required. Based on this consideration, we demonstrated a printable active microdisk resonator for protein adsorption sensing by using ink-jet printing fabrication method [3]..
27. Yuya Mikami, Soichiro Ryu, Cong Chen, Naoya Nishimura, Hiroaki Yoshioka, Yuji Oki, Water-like-refractive-index microdisk cavity by the ink-jet printing method, CLEO/Europe 2017, 2017.06, Summary form only given. Microdisk cavities are a kind of whispering gallery mode (WGM) resonators, which are continually studied owing to their high quality factor (Q factor) and small mode volume. These microdisks were previously fabricated using a subtractive method [1, 2] such as photolithography method. These subtractive methods are suitable for the mass-produced industrial structure due to an ability of the mass fabrication in large areas. On the other hand, we recently developed an ink-jet printing method as a novel, simple fabrication process for a full-polymeric fine microdisk, which is very superior at producing low waste materials, requires little energy consumption, and is suitable for on-site and on-demand fabrication because it is an additive method [3]. Since this method provides a completely organic microdisk platform, it is highly compatible with the biosensor. However, since the refractive index of used hyper-branched polymers (HBP) (n = 1.45-1.89) is a relatively high among organic materials, it is not preferable to use previous HBPs in a biosensor using a water-based liquid sample (n ~ 1.33) because of the short interaction length owing to reducing the evanescent part. In this study, we experimentally succeeded fabrication of microdisks with water-like refractive index by the ink-jet printing method. Additionally, the low-refractive-index microdisks doped with Rhodamine6G dye successfully achieved WGM lasing. This low-refractive-index microdisk cavity by ink-jet printing method is the first demonstration under atmospheric pressure and RT among inorganic microdisks..
28. Hiroaki Yoshioka, Yuya Mikami, Soichiro Ryu, Cong Chen, Naoya Nishimura, Yuji Oki, Silica-based inorganic microdisk cavity by the ink-jet printing method, CLEO/Europe 2017, 2017.06, We experimentally succeeded fabrication and WGM lasing of inorganic microdisks by the ink-jet printing method. This silica-based microdisk cavity is the first demonstration in ordinary pressure and temperature among inorganic microdisks..
29. Takeshi Komino, Yuta Sagara, Hiroyuki Tanaka, Yuji Oki, Nozomi Nakamura, Hiroshi Fujimoto, Chihaya Adachi, Highly efficient organic light-emitting diodes with completely oriented delayed fluorescent emitters
, CLEO/Europe 2017, 2017.06, We experimentally succeeded fabrication and WGM lasing of inorganic microdisks by the ink-jet printing method. This silica-based microdisk cavity is the first demonstration in ordinary pressure and temperature among inorganic microdisks..
30. Keisuke Nakakubo, Hiroaki Nomada, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Fully Printable Optical System Oriented Micro/Nano Fabrication by Configuration of Polydimethylsiloxane and Gallium, PITTCON 2017, 2017.03, In this paper, we report print-like-manufacturing study of SOT using low melting-point metal Ga and PDMS. Ga/PDMS boundary [8] can proved metallic reflection in optical quality in liquid-state. Firstly, inject and form liquid-state Ga into the PDMS, then cool and solidify Ga by cooling. Next, cure PDMS in room temperature with solid-state Ga mold. Due to the surface tension difference, spherical and semi-plane surface has sufficient quality for optically use. Reflection grating and mirror structure are also studied..
31. Yuya Mikami, Hirokazu Higuchi, Hirokazu Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Development of Image Diagnostic System for Absorption Measurement on Lab on a Tablet Concept, PITTCON 2017, 2017.03.
32. Junfeng Zhu, Hirokazu Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Quantum dot dispersed polydimethylsiloxane as wavelength shifting light source for optical analysis, PITTCON 2017, 2017.03.
33. Yuka Sonoda, Sae Iwata, Naho Watanabe, Masaki Kounoura, Yukihiko Yonemoto, Yuta Nakashima, Kinichi Morita, Yuji Oki, KOSUKE TASHIRO, Satoru Kuhara, Activation control of the cells on the titanium oxide substrate, ASIANALYSIS XIII, 2016.12, It is well known that the photofunctionalization by ultraviolet (UV) irradiation to Titanium substrate markedly promotes the osteogenesis. Photofunctionalization is surface processing
technique for improving implant surfaces such as orthopaedic / prosthetic-implant by luminous rays having specific wavelength and designated strength. The adhesiveness and function
expression of cells are considered to influence by the surface state (hydrophilic, hydrophobic, roughness, etc.) of substrate materials. It is common knowledge that cells strongly adhere to a
UV irradiated Ti substrate because affinity of Ti surface and cells is improved by UV surface modification. However, details of these phenomenon and mechanisms are not clarify. In this
study, the influence of surface modification of Ti substrates to cells was examined based on method of physical chemistry and biochemistry. The osteoblast cells (MC3T3) were used for
evaluating the photo functionalization effect of the Ti substrate. The adhesion/proliferation/
differentiation state of cells on the Ti substrate that was processed by the various UV
irradiation conditions were evaluated using fluorescence microscopic observation and
gene expression analysis..
34. Chalermpong Saenjum, Wasin Wongwilai, Hirokazu Higuchi, Kate Grudpan, Kinichi Morita, Yuji Oki, Validation of a novel portable spectrofluorometer for measuring rhodamine chloride and rhodamine 6G, ASIANALYSIS XIII, 2016.12.
35. Jungeng Zhu, Hirokazu Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Silicone based optical component development for 260 - 280nm ultraviolet optical analysis, ASIANALYSIS XIII, 2016.12.
36. Keisuke Nakakubo, Hiroaki Nomada, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Flexibly optical surface fabrication for mobile analysis using Gallium – polydimethylsiloxane molding process, ASIANALYSIS XIII, 2016.12.
37. Yuya Mikami, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Image Analysis System Development for Lab on a Tablet as Mobile / Field Analysis Device, ASIANALYSIS XIII, 2016.12.
38. Kinichi Morita, Kae Sato, Yuji Oki, Quantitative Analyses of protein by Bicinchoninic Acid (BCA) and Bradford Assays Using a Handheld Spectrometer
, “Workshop for Students/Young generations on Modern Chemical Analysis” ASIANALYSIS XIII, 2016.12, It is well known that the photofunctionalization by ultraviolet (UV) irradiation to Titanium substrate markedly promotes the osteogenesis. Photofunctionalization is surface processing
technique for improving implant surfaces such as orthopaedic / prosthetic-implant by luminous rays having specific wavelength and designated strength. The adhesiveness and function
expression of cells are considered to influence by the surface state (hydrophilic, hydrophobic, roughness, etc.) of substrate materials. It is common knowledge that cells strongly adhere to a
UV irradiated Ti substrate because affinity of Ti surface and cells is improved by UV surface modification. However, details of these phenomenon and mechanisms are not clarify. In this
study, the influence of surface modification of Ti substrates to cells was examined based on method of physical chemistry and biochemistry. The osteoblast cells (MC3T3) were used for
evaluating the photo functionalization effect of the Ti substrate. The adhesion/proliferation/
differentiation state of cells on the Ti substrate that was processed by the various UV
irradiation conditions were evaluated using fluorescence microscopic observation and
gene expression analysis..
39. Suherman, Kinichi Morita, Yuji Oki, Heavy Metals Detection using Conventional and Portable Instrumentation Systems
, “Workshop for Students/Young generations on Modern Chemical Analysis” ASIANALYSIS XIII, 2016.12.
40. Hiroaki Yoshioka, Cong Chen, Soichiro Ryu, Jifeng Li, Masaaki Ozawa, Yuji Oki, Ultra-low threshold lasing at 0.8 μm from organic microdisk cavity by the ink-jet printing method, 2016 Conference on Lasers and Electro-Optics, CLEO 2016, 2016.12, We demonstrated an ultra-low lasing threshold of 0.33 μJ/mm2 at 817.3 nm using an ink-jet-printed microdisk cavity doped with LDS798. Then microdisks with different tapered angles were evaluated on lasing threshold to perform low threshold..
41. Kazuhiro Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Impurity Analysis Study for Engine Coolant based on Mobile LIF Measurement, ICFIA 2016, 2016.10, Monitoring the impurity in an engine coolant is important maintenance for automobiles, trains, heavy equipment, and power generators. For quick and easy inspection in-situ, we propose a novel spectroscopic measurement method for the impurity monitoring by using laser induced fluorescence. Recently, we proposed Silicone Optical Technology (SOT) and demonstrated a PDMS optical chamber partially dispersed with carbon particle for optical spectroscopic measurements.[1] Folded optical path of the PDMS optical chamber can reduce the laser-stray noise and achieve high sensitivity in photoluminescence (PL) detection even though that chamber may be the palm-top size. [2]Since fluorescent dye was doped for the coolant, the fluorescence affected by coolant degradation can be measured in-situ with above PL modules using SOT..
42. Keisuke Nakakubo, Hiroaki Nomada, Kinichi Morita, Hiroaki Yoshioka, Yuji Oki, Micro/Nano Optical Fabrication and Integration in Ga-PDMS for Silicone Optical Technology
, ICFIA 2016, 2016.10, Recently, flow-injection analysis with optical detection are using solid-state light pass such as glass, polymer, and polydimethylsiloxane (PDMS) in comparison with optical pass of space in traditional optical systems. We proposed fully solid-state optical-pass made of PDMS for tiny and light optical system[1]. We named this concept as “Silicone Optical Technology(SOT)” and demonstrated simple absorabance meter [1], compact fluorometer [2], nobel optical crampmeter [3], and electronics-free optical system on tablet terminal (Lab-on-a-Table)[4]. Light collimater, reflector, optical trap, and color filter are realized by PDMS/air, carbon dispersed PDMS and dye doped PDMS. However, the complicated molding will be required to realize more functional SOT systems, such as micro lens array or moss-eye structure..
43. Yuji Oki, Hiroaki Yoshioka, Kinichi Morita, Development of Elemental Technology for Fully-Passive Optical System Fabrication on a Tablet Computer, ICFIA 2016, 2016.10, Recently, smartphone combined optical system was focused as mobile and easy system due to the improvement of their camera.[1] This concept means that mobile computer can became our commonly platform over the world. We assume that an optical system and a reaction chamber such as flow injection systems may be composed of passive devices only, and propose to utilize all functions of active device in the smart device. Since many optical system needs flat surface as their fundamentals, we proposed new concept of “Lab On a Tablet” in which the passive optical (and flow) system has optical interface with LCD and camera on the tablet surface. .
44. Hiroaki Nomada, Hirokazu Higuchi, Hirotaka Kuboyama, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Optimization of Absorption Measurement on Lab-on-a-Tablet System, Asia-Pacific Laser Symposium 2016, 2016.06, Abstract—Lab on a tablet concept, that is silicone optical system pasted on the tablet as an active optical breadboard. This work demonstrated an absorption spectroscopy on a PCR tube. The measurement accuracy is limited by the PCR entry in the black PDMS.
45. Hiroaki Nomada, Hirokazu Higuchi, Hirotaka Kuboyama, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Image Processing Optimization for Absorption Spectroscopy in PDMS Spectroscopy System Built upon
the Smart Tablets, BIOSENSORS 2016, 2016.05, [URL].
46. Hiroaki Nomada, Hirokazu Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Image Processing Optimization for Absorption Spectroscopy in PDMS Spectroscopy System Built upon the Smart Tablets, BIOSENSORS2016, 2016.05.
47. Hirokazu Higuchi, Hiroyuki Nomada, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Development of Silicone Filled Optical Module for Laser Fluorescence Trace Molecular
Detection, PITTCON 2016, 2016.03, Portable spectroscopy systems have been studied by many research groups[1,2]. The LIF (Laser Induced Fluorescence) method is useful for immunoassay[3], quench bodies [4] and so on. However, high sensitivity requires a very dark background, so reduction of.
48. Hiroyuki Nomada, Hirokazu Higuchi, Hiroaki Yoshioka, Kinichi Morita, Yuji Oki, Development of Optical “Clamp-meter” Using Silicone Optical Technology for In-situ
Absorption Spectroscopy, PITTCON 2016, 2016.03, Recently, we proposed novel optical design concept “SOT (silicone optical technology)”, in which PDMS (polydimethylsiloxane) is adopted as optical material to realize the compact system.[2] A light channel by SOT can suppress internal scattering light. It.
49. Cong Chen, Jifeng Li, Soichiro Ryu, Hiroaki Yoshioka, Masaaki Ozawa, Yuji Oki, Spectroscopic behavior in whispering-gallery modes by edge formation of printed microdisk lasers, SPIE Micro+Nano Materials, Devices, and Applications 2015 Conference, 2015.12.
50. Wasin Wongwilai, Yuji Oki, Hiroaki Yoshioka, Kin'ichi Morita, Kate Grudpan, Lab-on-a-Tablet – Flow based Analysis System (LOT-Flow), The 52th Annual Meeting of Japanese Association for Flow Injection Analysis, 2015.11.
51. Kanokwan Kiwfo, Wasin Wongwilai, Pheeraya Jaikang, Sutasinee Apichai, Kitti Phojuang, Yuji Oki, Kin'ichi Morita, Wasin Wongwilai, Kate Grudpan, Down scaling chemical analysis employing “PiCOSCOPE” and modern information technology, The 52th Annual Meeting of Japanese Association for Flow Injection Analysis, 2015.11.
52. Hirokazu Higuchi, Hiroaki Nomada, Hiroaki Yoshioka, Kin'ichi Morita, Yuji Oki, Absorbance-meter constructed by PDMS, 20th Microoptics Conference (MOC’15), 2015.10.
53. Kin'ichi Morita, Hiroaki Nomada, Hiroaki Yoshioka, Yuji Oki, Platform of optical analysis device based carbon-polydimethylsiloxane compound for spectroscopic chamber integration on information terminal, Flow Analysis XIII, 2015.07.
54. Mitsuhiro Nakano, Noboru Hirakawa, Hiroaki Yoshioka, Yuji Oki, On-site three-dimensional fabrication of organic optical system with micro-dispensing method, EOSOF, 2015.06, [URL], Fabrication technique based on “micro-dispensing method” have been developed for fully polymeric optical micro 3D system with additive manufacturing scheme. The technique provides polymeric optical system that contains microwire microridge, microbottle, and spindle-shaped microrod that mounted in high-precision control. Ultra-fine polymer microwire array successfully bridged in diameter of 1.0~1.5 μm. In addition, spindle shaped microrod was fabricated by irradiating a focused laser beam (1064 nm) . We have succeeded in the stacking prepolymer vertically. The rod diameter was approximately 40 μm, and maximum height of 100 μm was obtained.

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55. Soichiro Ryu, Hiroaki Yoshioka, Cong Chen, Kei Yasui, Yuji Oki, High-Q Printable Polymer Microdisk without Etching, CLEO/EUROPE, 2015.06, [URL].
56. Hiroaki Yoshioka, Noboru Hirakawa, Mitsuhiro Nakano, Yuji Oki, On-Demand Fabrication of Micro-Wired Rods and Nano-Coupling Control for 3D Polymeric Optical System, CLEO: 2015, 2015.05.
57. Yuji Oki, On-site Micro Painting of Optical Laser Cavities for Microchip Laser Driving, Laser Ignition Conference (LIC), 2015.04, Two types of polymeric microcavity fabrication method for DPSS pumping lasers were proposed and developed. WGM lasers were successfully fabricated. Polymeric microdisk with LDS798-doped microdisk and Rhodamine-6G-doped micro-wire array were demonstrated..
58. Hiroyuki Nomada, Hiroaki Yoshioka, Fan Yang, Kinichi Morita, Yuji Oki, Labo-On-Tablet, PITTCON 2015, 2015.03, Traditional spectroscopic systems are generally constructed by optical components aligned individually in a space. In addition, optical traps and outside shields are obliged to suppress background noise. To keep positioning accuracy, robust holding mechanisms must be fixed on a concrete foundation, and it makes optical systems larger, heavier, and more expensive.

We focus on optical performance of composite and hybrid material based on the PDMS (polydimethylsiloxane) that has good UV transparency and low reflection on optical contact with glasses. This compact and flexible PDMS optical module can be combined on a tablet terminal as an optical foundation that equips power source, light sources (LCD) and sensor camera. Attached PDMS optical system is monolithic and contains solid optical path, optical components, and light coupling interfaces with the LCD and the camera. Simple PCR tube absorbance-meter (Fig.1) was developed as first model of this Labo-On-Tablet (LOT). Polymeric optical fibers were embedded. PDMS doped with Carbon particle (Shinetsu, KE-COLOR-BL, ABS=72/cm) covered a transparent PDMS optical components to reduce outside background radiation and internal scattering. Furthermore, only reflectance of 0.95% per reflection/scattering was obtained.

Pick-up part of LCD light was newly proposed and developed based on reversed taper coupling scheme. The plastic optical fiber was terminated with slanted angle of 45 degree with no-coated surface. The light from LCD lighting spot was picked up, and guided to the PCR chamber. The transmitted light was collected by the POF on opposite side was bundled and guided to the optical detector (face camera) via prism and lens made of PDMS.

The measurement accuracy was evaluated with Sudan-I water ethanol solution with green LCD lighting. The face-camera captured images of terminated POF surface for 10 times at each concentration of 1μM to 1mM. The lighting spot of fiber was cropped and the pixel intensity was integrated over the spot as a signal. Experimentally obtained signal scattering of +-0.07%std in the 10 times continuous measurement. Since the scattering of +-0.13std was obtained when the PCR tube was ejected and reenter, their reproducibility about 0.05% can be estimated. The absorption sensitivity of 0.001 was also approximated from the calibration curve with single capturing. Thus, sensitivity of 0.0001 will be expected by using multiply capturing and averaging..
59. Mitsuhiro Nakano, Noboru Hirakawa, Hiroaki Yoshioka, Yuji Oki, Micro MOPA System Fabrication by Micro-dispensing Method, 19th International Conference on Flow Injection Analysis (19th ICFIA), 2014.12.
60. Mitsuhiro Nakano, Noboru Hirakawa, Hiroaki Yoshioka, Yuji Oki, Printed Micro-waveguide MOPA system, The 67th Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 2014.09.
61. Yuji Oki, Kenitchi Iwamoto, Kunio Awadu, Diagnosis of Dental Caries using LIBS with Passively Q-switched Nd:YAG Microchip Laser, Laser Ignition Conference (LIC), 2014.04, Two types of polymeric microcavity fabrication method for DPSS pumping lasers were proposed and developed. WGM lasers were successfully fabricated. Polymeric microdisk with LDS798-doped microdisk and Rhodamine-6G-doped micro-wire array were demonstrated..
62. 興 雄司, Print-like Fabrications on Polymeric Optical and Optoelectronics Devices, Pusan National University Joint Symposium 2013, 2013.06.
63. 4-layered waveguides fabrication for distributed feedback solid state dye lasers with pen-drawing method technique.
64. Methane Leakage Detector using DIAL Vol.III.
65. H2 Gas Detection using SRGS with Raman Shifter.
66. Nanoscale Solid Surface Analysis due to Laser Ablation Atomic Fluorescence Spectroscopy.
67. Laser dioded injection seeded optical parametric oscillator.
68. DIAL aiming Green House Gas Detection.
69. Trace Gas Detection by PARS and CARS without Wavelength Tuning.