||Zhongyuan Yang, Fumihiro Sassa, Kenshi Hayashi, A Robot Equipped with a High-Speed LSPR Gas Sensor Module for Collecting Spatial Odor Information from On-Ground Invisible Odor Sources, ACS Sensors, 2018.06.
||Xiaoguang Ying, Hiro Taka Yoshioka, Chuanjun Liu, Fumihiro Sassa, Kenshi Hayashi, Molecular imprinting technique in putrescine visualized detection, Sensors and Actuators, B: Chemical, 10.1016/j.snb.2017.11.128, 258, 870-880, 2018.04, This work is an exploration into visualizing measurement of putrescine specific adsorption by photographing colorized molecule imprinting chromogenic hydrogel. Membranes are prepared with imitate templates 1,4-butylene glycol, adipic acid or succinic acid, respectively and ninhydrin is used as chromogenic agent for target molecule putrescine. The adsorbing concentration on MIP is reflected in the form of visible violet-colored stain differed in shape and shade, which are recorded by hyper spectral camera and proceeded into intuitive 3D isohypse surfaces plot. By quantifying the height of surface peaks, imprinting efficiency is estimated in accordance with polyvinyl alcohol concentration and crosslinking degree. The imprinting efficiency of three imitate molecule templates is also discussed..
||Keigo Nakanishi, Fumihiro Sassa, Kenshi Hayashi, Photo-tunable molecular recognizing smart material for gas sensing, 19th International Conference on Solid-State Sensors, Actuators and Microsystems, TRANSDUCERS 2017
TRANSDUCERS 2017 - 19th International Conference on Solid-State Sensors, Actuators and Microsystems, 10.1109/TRANSDUCERS.2017.7994313, 1376-1379, 2017.07, We developed a dynamic photo-tunable gas adsorbent based on smart (photo sensitive) material and molecularly imprinted polymer (MIP) technology . Gas adsorption property of the material, mixture of photochromic materials and polymethyl methacrylate (PMMA), can be controlled reversible and continuously by irradiation of with light different wavelength. As a result, gas sensor which is composed of a quartz crystal microbalance (QCM) coated with the developed adsorbent was fabricated. This sensor system can detect a certain gas molecule corresponding to the adsorbent property from gas mixture with only one sensor node..
||Takahiro Watanabe, Fumihiro Sassa, Yoshitaka Yoshizumi, Hiroaki Suzuki, Review of Microfluidic Devices for On-Chip Chemical Sensing, Electronics and Communications in Japan, 10.1002/ecj.11944, 100, 4, 25-32, 2017.04, Microfluidic techniques can be a basis to realize user-friendly microanalytical devices of high performance. Required operations include injection of solutions to reaction chambers, volume measurement, and mixing of solutions. For this purpose, the use of surface tension is attractive. In hydrophobic flow channels, solutions can be moved stably in the form of plugs. Otherwise, solutions can be transported by capillary action in a hydrophilic flow channel and stopped at a hydrophobic valve. The valve can be opened autonomously by switching the mixed potential by wetting a zinc electrode formed in a controlling flow channel. In this review paper, we introduce some of our microfluidic devices particularly focusing on devices that work based on surface tension..
||Masashi Watanabe, Fumihiro Sassa, Kenshi Hayashi, Formation of oriented metal nanostructures by polarized light irradiation for optical sensing, 15th IEEE Sensors Conference, SENSORS 2016
IEEE Sensors, SENSORS 2016 - Proceedings, 10.1109/ICSENS.2016.7808850, 2017.01, Highly sensitive optical sensing of molecules can be achieved by using localized surface plasmon generated at metal nanostructures, such as SERS-based sensing. We fabricated SERS-active silver nanostructures by using polarized light irradiation, and evaluated their response properties to rhodamine 6G. In this paper, it is shown that strong Raman signals of rhodamine 6G and large variation in optical transmission have been obtained. Especially, the transmission spectra of the silver nanostructures grown under the irradiation of polarized light showed unique polarizing properties derived from different modes of localized surface plasmons, which would be useful in smart optical sensing..
||Sho Shinohara, Fumihiro Sassa, Kenshi Hayashi, Gas selective chemiresistor composed of molecularly imprinted polymer composit ink, 15th IEEE Sensors Conference, SENSORS 2016
IEEE Sensors, SENSORS 2016 - Proceedings, 10.1109/ICSENS.2016.7808660, 2017.01, Gas sensor with high molecular selectivity is highly demanded in many fields of industry or disaster relief. Molecularly imprinted polymer (MIP) can recognize target gas by specific adsorption for template molecule. In this study, a novel chemiresistor, gas sensor which combined with MIP and conductive nanoparticles has been developed. The gases were distinguished based on molecularly structure by MIP. If gas molecule is absorbed into this polymer, structures and properties of conductive composites are changed. It causes electric resistance changed. It is conceivable that the degree of resistance change is dependent upon the amount of absorption. Moreover, MIP absorbs larger quantity of template molecule than similar gas molecule. So this MIP chemiresistor can be used for measurement of specific target gas based on magnitude of response. Measurement results of gas sensing showed that larger response was produced by MIP chemiresistor for the template molecule than other gas and NIP (non-imprinted polymer) composite. It means that a sensor which could both recognizing molecules and transduce electrical signal simultaneously was successfully developed..
||Satoshi Araki, Masashi Watanabe, Fumihiro Sassa, Kenshi Hayashi, Raman enhanced structure with reconfigured molecularly-imprinted-polymer for gas deteciton, 15th IEEE Sensors Conference, SENSORS 2016
IEEE Sensors, SENSORS 2016 - Proceedings, 10.1109/ICSENS.2016.7808604, 2017.01, Various devices are developed to obtain information of odor for crisis evasion in dangerous situation. However, the improvement of sensing methodology is lagging. Therefore, some novel odor sensors with high sensitivity, selectivity and short response time are required. Gas detection based on surface enhanced Raman scattering (SERS) is a promising technology to realize such sensor. We developed a sandwich structured SERS substrate with an organic layer, which was placed between an Au thin layer and a gold nano particles (AuNPs) layer. Furthermore, the organic layer was reconfigured to molecularly imprinted polymer (MIP) for selective gas detection. Raman spectrum obtained with a MIP-SERS substrate shows the appearance of peak based on 2-phenylethanol that is targeted gas molecule. Compared with non-imprinted polymer (NIP), MIP substrate showed stronger SERS signals..
||Sho Shinohara, You Chiyomaru, Fumihiro Sassa, LIU CHUANJUN, Kenshi Hayashi, Molecularly Imprinted Filtering Adsorbents for Odor Sensing, Sensors, 10.3390/s16111974 , 16, 11, 1974, 2016.11, Versatile odor sensors that can discriminate among huge numbers of environmental odorants are desired in many fields, including robotics, environmental monitoring, and food production. However, odor sensors comparable to an animal’s nose have not yet been developed. An animal’s olfactory system recognizes odor clusters with specific molecular properties and uses this combinatorial information in odor discrimination. This suggests that measurement and clustering of odor molecular properties (e.g., polarity, size) using an artificial sensor is a promising approach to odor sensing. Here, adsorbents composed of composite materials with molecular recognition properties were developed for odor sensing. The selectivity of the sensor depends on the adsorbent materials, so specific polymeric materials with particular solubility parameters were chosen to adsorb odorants with various properties. The adsorption properties of the adsorbents could be modified by mixing adsorbent materials. Moreover, a novel molecularly imprinted filtering adsorbent (MIFA), composed of an adsorbent substrate covered with a molecularly imprinted polymer (MIP) layer, was developed to improve the odor molecular recognition ability. The combination of the adsorbent and MIP layer provided a higher specificity toward target molecules. The MIFA thus provides a useful technique for the design and control of adsorbents with adsorption properties specific to particular odor molecules. .
||Kazuhiro Ikemoto, Takafumi Seki, Shohei Kimura, Yui Nakaoka, Shinnosuke Tsuchiya, Fumihiro Sassa, Masatoshi Yokokawa, Hiroaki Suzuki, Microfluidic Separation of Redox Reactions for Coulometry Based on Metallization at the Mixed Potential, Analytical Chemistry, 2016.09.
||Hirotaka Obata, Tomoaki Kuji, Kenichi Kojima, Fumihiro Sassa, Masatoshi Yokokawa, Kazuhiro Takekoshi, Hiroaki Suzuki, Electrochemical Bubble-Based Bidirectional Microfluidic Transport, ACS Sensors, 1, 2, 190, 2015.12.
||Tomomi Sakata, Fumihiro Sassa, Mitsuo Usui, Junichi Kodate, Hiromu Ishii, Katsuyuki Machida, Yoshito Jin, Monolithically integrated MEMS mirror array with low electrical interference in wavelength-selective switches, Precision Engineering, 37, 4, 897, 2013.10.
||Tomomi Sakata, Keita Yamaguchi, Naru Nemoto, Mitsuo Usui, Fumihiro Sassa, Kazuyoshi Ono, Kazuhiko Takagahara, Kei Kuwabara, Junichi Kodate, Yoshito Jin, Elimination of Curvature in Microelectromechanical-System Membrane, ECS Transactions, 53, 5, 29, 2013.05.
||Daisuke Itoh, Fumihiro Sassa, Taiji Nishi, Yoko Kani, Masakazu Murata, Hiroaki Suzuki, Droplet-based microfluidic sensing system for rapid fish freshness determination, Sensors and Actuators B: chemical, 17, 619, 2012.09.
||Fumihiro Sassa, Yazan Al-Zain, Takahiro Ginoza, Shuichi Miyazaki, Hiroaki Suzuki, Miniaturized shape memory alloy pumps for stepping microfluidic transport, Sensors and Actuators B: Chemical, 165, 1, 157, 2012.04.
||Fumihiro Sassa, Hind Laghzali, Junji Fukuda, Hiroaki Suzuki, Coulometric detection of components in liquid plugs by microfabricated flow channel and electrode structures, Analytical chemistry, 82, 20, 8725, 2010.09.
||Yuki Seto, Rina Inaba, Tomoaki Okuyama, Fumihiro Sassa, Hiroaki Suzuki, Junji Fukuda, Engineering of capillary-like structures in tissue constructs by electrochemical detachment of cells, Biomaterials, 31, 8, 2209, 2010.03.
||Shintaro Takahashi, Hironori Yamazoe, Fumihiro Sassa, Hiroaki Suzuki, Junji Fukuda, Preparation of coculture system with three extracellular matrices using capillary force lithography and layer-by-layer deposition, Journal of bioscience and bioengineering, 108, 6, 544, 2009.12.
||Yoshifumi Shimizu, Atsushi Takashima, Wataru Satoh, Fumihiro Sassa, Junji Fukuda, Hiroaki Suzuki, Biochip with integrated pumps for plug-based sequential exchange of solutions, Sensors and Actuators B: Chemical, 140, 2, 649, 2009.07.
||Wataru Satoh, Shintaro Takahashi, Fumihiro Sassa, Junji Fukuda, Hiroaki Suzuki, On-chip culturing of hepatocytes and monitoring their ammonia metabolism, Lab on a Chip, 9, 1, 35, 2009.01.
||Fumihiro Sassa, Junji Fukuda, Hiroaki Suzuki, Microprocessing of liquid plugs for bio/chemical analyses, Analytical chemistry, 80, 16, 6206, 2008.07.
||Fumihiro Sassa, Katsuya Morimoto, Wataru Satoh, Hiroaki Suzuki, Electrochemical techniques for microfluidic applications, Electrophoresis, 29, 9, 1787, 2008.05.