Fundamental technologies for using lasers for insitu measurement of the composition of marine particles

• Project/Area Number: 18H03810
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: The University of Tokyo
• Principal Investigator: Thornton Blair 東京大学, 生産技術研究所, 准教授 (60526789)
• Co-Investigator(Kenkyū-buntansha): 高橋 朋子 国立研究開発法人海洋研究開発機構, 超先鋭研究開発部門(超先鋭技術開発プログラム), Young Research Fellow (20806301) ; Liu Zonghua 東京大学, 生産技術研究所, 特任研究員 (90844449)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥44,720,000 (Direct Cost: ¥34,400,000、Indirect Cost: ¥10,320,000); Fiscal Year 2020: ¥10,790,000 (Direct Cost: ¥8,300,000、Indirect Cost: ¥2,490,000); Fiscal Year 2019: ¥13,650,000 (Direct Cost: ¥10,500,000、Indirect Cost: ¥3,150,000); Fiscal Year 2018: ¥20,280,000 (Direct Cost: ¥15,600,000、Indirect Cost: ¥4,680,000)
• Keywords: レーザ分光 / ラマン分光 / ホログラフィック / 化学分析 / 現場計測 / 粒子分析 / センシング / レーザー分光 / 粒子計測

Outline of Final Research Achievements

We developed a sensor capable of measuring different types suspended marine particles, including organic carbon, inorganic carbon, micro-plastics and minerals. The sensor uses a laser beam and observes the light that is scattered by particles in seawater. The sensor can differentiate between the different types of particle in the environment by analysing the scattered light signals using machine learning. We verified the performance of our system in controlled laboratory experiments and during sea-trials. Unlike sensors that mix chemical reagents to make measurements, or those that perform physical sampling, the method developed here can make observations continuously provided electrical power can be supplied, making the developed method highly suitable for the large scale, persistent observations needed to better understand the role of marine particles on global scale chemical cycles.

Academic Significance and Societal Importance of the Research Achievements

本研究により、長期・大規模に展開可能な小型・低消費電力及びローコストな海中浮遊粒子の化学センシング技術の基礎を構築し、これまでセンシングできなかった水中における粒子の化学成分の計測を実現した。今後、社会的に重大な地球環境問題のひとつであるマイクロプラスチックスの計測をグローバルスケールで行うことが期待される。社会的意義としては、試薬等を使わないためコンタミの恐れがないため、発電所や自動車、また飲料水のパイプライン内に流れる液体中の腐食物質検出など、インフラのモニタリングに応用が可能であり、さらには、地球外の水環境調査への応用へと道が拓ける。

Research Products

• [Int'l Joint Research] Aberdeen University/University of Southampton(英国)
• [Int'l Joint Research] University of Southampton/University of Aberdeen(英国)
• [Int'l Joint Research] Schemadt Ocean Institute(米国)
• [Journal Article] Digital In-line Holography for Large-Volume Analysis of Vertical Motion of Micro-scale Marine Plankton and Other Particles (2021)
  • Author(s): Zonghua Liu, Tomoko Takahashi, Dhugal Lindsay, Thangavel Thevar, Mehul Sangekar, Hiromi Watanabe, Nick Burns, John Watson, and Blair Thornton
  • Journal Title: Journal of Oceanic Engineering(accepted) Volume: -
  • Peer Reviewed / Open Access
• [Journal Article] Quantitative in situ mapping of elements in deep-sea hydrothermal vents using laser-induced breakdown spectroscopy and multivariate analysis (2020)
  • Author(s): Takahashi Tomoko、Yoshino Soichi、Takaya Yutaro、Nozaki Tatsuo、Ohki Koichi、Ohki Toshihiko、Sakka Tetsuo、Thornton Blair
  • Journal Title: Deep Sea Research Part I: Oceanographic Research Papers Volume: 158 Pages: 103232-103232
  • DOI: 10.1016/j.dsr.2020.103232
  • Peer Reviewed / Open Access
• [Journal Article] Identification of microplastics in a large water volume by integrated holography and Raman spectroscopy (2020)
  • Author(s): Tomoko Takahashi, Zonghua Liu, Thangavel Thevar, Nicholas Burns, Sumeet Mahajan, Dhugal Lindsay John Watson, Blair Thornton
  • Journal Title: Applied Optics Volume: - Issue: 17 Pages: 5073-5073
  • DOI: 10.1364/ao.393643
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Partial least squares regression calculation for quantitative analysis of metals submerged in water measured using laser-induced breakdown spectroscopy (2018)
  • Author(s): Takahashi, T., Thornton, B., Sato, T., Ohki, T., Ohki, K. & Sakka, T.
  • Journal Title: Applied Optics Volume: 57 Issue: 20 Pages: 5872-5883
  • DOI: 10.1364/ao.57.005872
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Signal preprocessing of deep-sea laser-induced plasma spectra for identification of pelletized hydrothermal deposits using Artificial Neural Networks (2018)
  • Author(s): Yoshino Soichi、Thornton Blair、Takahashi Tomoko、Takaya Yutaro、Nozaki Tatsuo
  • Journal Title: Spectrochimica Acta Part B: Atomic Spectroscopy Volume: 145 Pages: 1-7
  • DOI: 10.1016/j.sab.2018.03.015
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Classification and statistical analysis of hydrothermal seafloor rocks measured underwater using laser-induced breakdown spectroscopy (2018)
  • Author(s): Yelameli, M., Thornton, B., Takahashi, T., Weerkoon, T. & Ishii, K.
  • Journal Title: Journal of Chemometrics Volume: Vol.33, No.2 Issue: 2
  • DOI: 10.1002/cem.3092
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Fast classification of microplastics by hyphenated-Raman techniques (2020)
  • Author(s): T. Takahashi, Z. Liu, K. Bourdakos, T. Thevar, N. Burns, D. Lindsay, J. Watson, B. Thornton, and S. Mahajan
  • Organizer: The XXVII International Conference on Raman Spectroscopy
  • Int'l Joint Research
• [Presentation] Comparison of region proposal methods for marine holograms (2020)
  • Author(s): Z. Liu, T. Takahashi, T. Thevar, D. Lindsay, N. Burns, J. Watson, and B. Thornton
  • Organizer: Global OCEANS 2020
  • Int'l Joint Research
• [Presentation] Shape-based image classification and identification system for digital holograms of marine particles and plankton (2020)
  • Author(s): Z. Liu and J. Watson
  • Organizer: Global OCEANS 2020
  • Int'l Joint Research
• [Presentation] Development of Elemental Technologies for Seafloor Mineral Processing of Seafloor Massive Sulfides (2019)
  • Author(s): Yasuharu Nakajima, Joji Yamamoto, Tomoko Takahashi, Blair Thornton, Yuta Yamabe, Gjergj Dodbiba & Toyohisa Fujita
  • Organizer: OMAE 2019
  • Int'l Joint Research
• [Presentation] Imaging techniques for surveys of gelatinous zooplankton: Holographs, shadowgraphs, laser scanning and 3D reconstructions (2019)
  • Author(s): Lindsay DJ, Hidaka M, Sangekar M, Nishikawa J,, Hopcroft RR, Thornton B, Yamamoto H, Kawahito Y.
  • Organizer: 9th Hydrozoan Society Workshop
  • Int'l Joint Research
• [Presentation] Development of in-situ LIBS and Raman spectroscopic analysers for exploration of deep-sea hydrothermal vent fields (2018)
  • Author(s): Takahashi, T., Yoshino, S., Takaya, Y., Nozaki, T., Ohki, T., Ohki, K., Sakka, T. & Thornton, B
  • Organizer: SciX, USA
  • Int'l Joint Research
• [Presentation] Measurement of metal grade of ore particles in slurry using laser-induced breakdown spectroscopy (2018)
  • Author(s): Nakajima, Y., Yamamoto, J., Takahashi, T., Dodbiba, G., Thornton, B., Fujita, T.
  • Organizer: OCEANS’18 Kobe, Kobe, Tokyo
  • Int'l Joint Research
• [Remarks]
  • URL: https://schmidtocean.org/artificial-intelligence-guides-rapid-data-driven-exploration/