Skin Iontronic Biomedical Engineering

2021 Fiscal Year Final Research Report

• Project/Area Number: 20K21877
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 90:Biomedical engineering and related fields
• Research Institution: Tohoku University
• Principal Investigator: Nishizawa Matsuhiko 東北大学, 工学研究科, 教授 (20273592)
• Co-Investigator(Kenkyū-buntansha): 吉田 昭太郎 中央大学, 理工学部, 助教 (20785349)
• Project Period (FY): 2020-07-30 – 2022-03-31
• Keywords: 表皮電位

Outline of Final Research Achievements

Transepidermal potential (TEP), an electrical potential difference of tens of millivolts that is generated along the thickness direction of the epidermis, is a possible indicator of epidermal function, including the permeability barrier of skin. Herein, a patch-type wearable device for minimally invasive monitoring of TEP was developed by utilizing a porous microneedle (PMN) array made of an epoxy resin. In order to measure the potential of the subepidermal tissue, the entire surface of the PMN except for the needle tip was coated by a thin film of insulating parylene C. The open-tip PMN was integrated with a wearable potentiometric device composed of a pair of screen-printed Ag/AgCl electrodes. By optimizing the porosity and the size of the liquid junction, the TEP of tens of mV at a subject’s forearm was successfully monitored over a 4 h period.

Free Research Field

生体イオントロニクス

Academic Significance and Societal Importance of the Research Achievements

脳や筋肉に大きく遅れて，近年，皮膚がイオニックなシステムであることが徐々に解明され始めたが，これまでの皮膚科学の手法は生化学的なアプローチが主であった。本研究で開拓を目指した「皮膚イオニクス医工学」は，神経・筋肉系で確立を遂げた電気的な計測・制御の技術体系を皮膚に展開し，皮膚のイオニックな構造・機能連関を解明して医療工学につなげる新分野となる。本研究によって、未解明な自律的皮膚感覚のメカニズムに表皮電位計測で迫り，アトピーなど皮膚疾患の電気的な診断・治療法の開発に挑む新分野の土台を創り出すことができたと考えている。