title: Spirulina-templated metal microcoils with controlled helical structures for THz electromagnetic responses.
abstract: Microstructures in nature are ultrafine and ordered in biological roles, which have attracted material scientists. Spirulina forms three-dimensional helical microstructure, one of remarkable features in nature beyond our current processing technology such as lithography in terms of mass-productivity and structural multiplicity. Spirulina varies its diameter, helical pitch, and/or length against growing environment. This unique helix is suggestive of a tiny electromagnetic coil, if composed of electro-conductive metal, which brought us main concept of this work. Here, we describe the biotemplating process onto Spirulina surface to fabricate metal microcoils. Structural parameters of the microcoil can be controlled by the cultivation conditions of Spirulina template and also purely one-handed microcoil can be fabricated. A microcoil dispersion sheet exhibited optically active response attributed to structural resonance in terahertz-wave region.
authors.affiliation: 1] Iyoda Supra-Integrated Material Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [2] Research Society for Biotemplate Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Kamata
authors.affiliation: Iyoda Supra-Integrated Material Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Zhenzi
authors.initials: Z
authors.lastname: Piao
authors.affiliation: Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Soichiro
authors.initials: S
authors.lastname: Suzuki
authors.affiliation: Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Fujimori
authors.affiliation: Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Tajiri
authors.affiliation: 1] Iyoda Supra-Integrated Material Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [2] Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Nagai
authors.affiliation: 1] Iyoda Supra-Integrated Material Project, Exploratory Research for Advanced Technology (ERATO), Japan Science and Technology Agency (JST), 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [2] Research Society for Biotemplate Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [3] Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan.
authors.forename: Tomokazu
authors.initials: T
authors.lastname: Iyoda
authors.affiliation: 1] Research Society for Biotemplate Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [2] Technology and Engineering Department, Materials Division, Sumitomo Metal Mining Co. Ltd., 5-11-3 Shimbashi, Minato-Ku, Tokyo 105-8716, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamada
authors.affiliation: 1] Research Society for Biotemplate Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [2] Advantest Laboratories Ltd., 48-2 Matsubara, Kami-Ayashi, Aoba-Ku, Sendai, Miyagi 989-3124, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Hayakawa
authors.affiliation: DIC LIFETEC Co., Ltd., 12 Yawata-Kaigandori, Ichihara, Chiba 290-8585, Japan.
authors.forename: Mitsuteru
authors.initials: M
authors.lastname: Ishiwara
authors.affiliation: DIC LIFETEC Co., Ltd., 12 Yawata-Kaigandori, Ichihara, Chiba 290-8585, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horaguchi
authors.affiliation: Earthrise Nutritionals, LLC., 113 E. Hoober Road Calipatria, CA 92233, USA.
authors.forename: Amha
authors.initials: A
authors.lastname: Belay
authors.affiliation: 1] Research Society for Biotemplate Technology, 4259 Nagatsuta-Cho, Midori-Ku, Yokohama, Kanagawa 226-8503, Japan [2] Metamaterials Laboratory, Advanced Science Institute, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Takuo
authors.initials: T
authors.lastname: Tanaka
authors.affiliation: Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Takano
authors.affiliation: Institute of Laser Engineering, Osaka University, 2-6 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Hangyo
mesh_terms: D055590:Electromagnetic Phenomena; D008670:Metals / Q000737:chemistry; D053545:Spirulina
chemical_list: D008670:Metals