Ultraflexible organic amplifier with biocompatible gel electrodes

• Published in: Nature communications Vol. 7; no. 1; pp. 11425 - 11
• Main Authors: Sekitani, Tsuyoshi, Yokota, Tomoyuki, Kuribara, Kazunori, Kaltenbrunner, Martin, Fukushima, Takanori, Inoue, Yusuke, Sekino, Masaki, Isoyama, Takashi, Abe, Yusuke, Onodera, Hiroshi, Someya, Takao
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 29.04.2016; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301/1023/1025; 639/301/119/544; 639/638/309; 9/10; Animals; Biocompatibility; Biocompatible Materials - chemistry; Biocompatible Materials - pharmacology; Cell Line; Cell Survival - drug effects; Dermis - drug effects; Dermis - physiology; Electrocardiography; Electrocardiography - instrumentation; Electrodes; Electronics - instrumentation; Electronics - methods; Fabrication; Female; Fibroblasts - cytology; Fibroblasts - drug effects; Foreign-Body Reaction - prevention & control; Goats; Humanities and Social Sciences; Hydrogels; Hydrogels - chemistry; Hydrogels - pharmacology; Male; Monitoring systems; multidisciplinary; Nanotubes, Carbon - chemistry; Naphthalenes - chemistry; Pericardium - drug effects; Pericardium - physiology; Pliability; Polyethylene; Polyethylenes - chemistry; Rabbits; Rats; Science; Science (multidisciplinary); Tissues; Transistors; Japan
• DOI: 10.1038/ncomms11425
• ISSN: 2041-1723

In vivo electronic monitoring systems are promising technology to obtain biosignals with high spatiotemporal resolution and sensitivity. Here we demonstrate the fabrication of a biocompatible highly conductive gel composite comprising multi-walled carbon nanotube-dispersed sheet with an aqueous hydrogel. This gel composite exhibits admittance of 100 mS cm −2 and maintains high admittance even in a low-frequency range. On implantation into a living hypodermal tissue for 4 weeks, it showed a small foreign-body reaction compared with widely used metal electrodes. Capitalizing on the multi-functional gel composite, we fabricated an ultrathin and mechanically flexible organic active matrix amplifier on a 1.2-μm-thick polyethylene-naphthalate film to amplify (amplification factor: ∼200) weak biosignals. The composite was integrated to the amplifier to realize a direct lead epicardial electrocardiography that is easily spread over an uneven heart tissue. Flexible electronics promise the opportunity to monitor biological activity via implanted devices. Here, the authors develop a biocompatible conductive carbon nanotube/gel composite and couple it with an ultrathin flexible amplifier, enabling in vivo measurement of epicardial electrocardiogram signals.