Totally transparent hydrogel-based subdural electrode with patterned salt bridge

Ayaka Nishimura, Ryota Suwabe, Yuka Ogihara, Shotaro Yoshida, Hiroya Abe, Shin ichiro Osawa, Atsuhiro Nakagawa, Teiji Tominaga, Matsuhiko Nishizawa

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


A totally transparent subdural electrode was developed by embedding a conductive poly (vinyl alcohol) (PVA)-filled microchannel made of poly(dimethylsiloxane) (PDMS) into an another PVA hydrogel substrate. Tight bonding between the PVA substrate and the PDMS microchannel (salt bridge) was achieved by mechanical interlocking utilizing the microprotrusions formed on the microchannel. This simple method of bonding without the use of any additives such as silane molecules or nanofibers is very suitable for constructing biomedical devices. The salt bridge electrode (total thickness, ca. 1.5 mm) was sufficiently soft, and showed superior shape conformability that makes it an excellent choice as a subdural electrode used on the brain surface. In vivo measurement proved that the salt bridge electrode makes close contact to the exposed porcine brain and can record brain wave signals of frequencies 1 ~ 15 Hz. In addition, the high transparency of the electrode provided a clear view of the brain surface that would assist the effective surgical operation and optogenetic research.

Original languageEnglish
Article number57
JournalBiomedical microdevices
Issue number3
Publication statusPublished - 2020 Sep 1


  • Brain wave measurement
  • Hydrogel
  • Ionic circuit
  • Salt bridge
  • Subdural electrode

ASJC Scopus subject areas

  • Biomedical Engineering
  • Molecular Biology


Dive into the research topics of 'Totally transparent hydrogel-based subdural electrode with patterned salt bridge'. Together they form a unique fingerprint.

Cite this