Elucidation of Subdomain Structures in Ferroelectric Polymers by Scanning Probe Microscopy

• Project/Area Number: 20K04566
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 21050:Electric and electronic materials-related
• Research Institution: Kansai University
• Principal Investigator: Takarada Jun 関西大学, システム理工学部, 准教授 (40637089)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2022: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2021: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2020: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 圧電応答力顕微鏡 / 相転移メカニズム

Outline of Research at the Start

本研究は強誘電高分子膜の分極反転や相転移メカニズムの解明に貢献する．これにより最終的にフレキシブルな身に着けるデバイスが持つ情報を一時的に保存する次世代のメモリを提供することにつながる．分極反転や相転移のメカニズムをカンチレバーの接触共振を使ったプローブ顕微技術によって評価する．本評価から本膜をメモリとして活用するための記憶密度，書込読出の時間や電圧，温度耐性等の指標を提供する．

Outline of Final Research Achievements

The purpose of this study is to elucidate the phase transition mechanism of ferroelectric polymer films by scanning probe microscopy.
Using a contact resonance PFM, we observed the polarization region in the micro region of ferroelectric polymers. The phase transition temperatures varied from 60°C to 80°C at the macroscopic viewpoint because the phase transition temperatures were different for each particle. The results of this research will provide indices such as memory density and temperature tolerance for utilizing this film as a memory.
Lateral PFM was also used to observe the electromechanical response of particles of highly biodegradable polymers. By increasing the annealing time, different positive and negative electromechanical responses were obtained within the particles. The results are expected to be applied to environmentally friendly sensors with high biodegradability.

Academic Significance and Societal Importance of the Research Achievements

研究成果の学術的意義は強誘電高分子を数百nmスケールで観た時に、その相転移は粒子毎に生じていたことにある．巨視的に観た時の相転移温度に幅があることは以前からわかっていたがその原因の解明に一歩近づいた．また強誘電相から常誘電相に転移した温度においては粒子固有の分極域を持っているが、隣接する粒子とは反対の位相を持っているため、巨視的に観ると相殺されて強誘電性が消失していることが観測できた．
社会的意義は本膜をメモリとして活用するための記憶密度，温度耐性等の指標を提供できたことである．未来のIoT社会にフレキシブルなデバイスが持つ膨大なデータを支える次世代のメモリとして活用することにつながる．

Research Products

• [Journal Article] Application of Piezoelectric PLLA Braided Cord as Wearable Sensor to Realize Monitoring System for Indoor Dogs with Less Physical or Mental Stress (2023)
  • Author(s): Y. Tajitsu,et al.
  • Journal Title: Micromachines Volume: 14 Issue: 1 Pages: 143-143
  • DOI: 10.3390/mi14010143
  • Peer Reviewed / Open Access
• [Journal Article] Frequency response analysis of piezoelectric resonance of poly-lactic acid film for bending angle detection (2022)
  • Author(s): Takarada Jun, Nakanishi Riku, Wang Yizhao, Yamamoto Ken, Mori Kenichi, Ando Masamichi, Tajitsu Yoshiro
  • Journal Title: Japanese Journal of Applied Physics Volume: 61 Issue: SN Pages: SN1035-SN1035
  • DOI: 10.35848/1347-4065/ac85f8
  • Peer Reviewed
• [Journal Article] A Prototype Sensor System Using Fabricated Piezoelectric Braided Cord for Work-Environment Measurement during Work from Home (2021)
  • Author(s): Yoshiro Tajitsu, Jun Takarada, et al.
  • Journal Title: Micromachines Volume: 12 Issue: 8 Pages: 966-978
  • DOI: 10.3390/mi12080966
  • Peer Reviewed / Open Access
• [Journal Article] Local Evaluation of Piezoelectricity of Polyester Polymer Processed with Microwave Heating (2021)
  • Author(s): Jun TAKARADA, Yifu TANG, Takaaki TONE, Kohei TAKATANI, Shingo TANAKA, Yoshihiko NISHIZAWA, Masamichi ANDO, Daisuke MANAI, Masayuki KABATA, Tomoya MIZUMORI, Makoto KUSUNOKI, Takanori MATSUYAMA and Yoshiro TAJITSU
  • Journal Title: 静電気学会誌 Volume: 45 Pages: 28-33
  • NAID: 40022500382
  • Peer Reviewed
• [Presentation] Local Observation of Depolarization of Poly(vinylidene fluoride/trifluoroethylene) 55/45 film Using Piezoresponse Force Microscopy (2021)
  • Author(s): Jun Takarada, Takaaki Tone, Shota Saihara, Yoshiro Tajitsu
  • Organizer: IEEE ISAF2021
  • Int'l Joint Research