Soft, curved electrode systems capable of integration on the auricle as a persistent brain-computer interface

James J.S. Norton, Dong Sup Lee, Jung Woo Lee, Woosik Lee, Ohjin Kwon, Phillip Won, Sung Young Jung, Huanyu Cheng, Jae Woong Jeong, Abdullah Akce, Stephen Umunna, Ilyoun Na, Yong Ho Kwon, Xiao Qi Wang, Zhuang Jian Liu, Ungyu Paik, Yonggang Huang, Timothy Bretl, Woon Hong Yeo, John A RogersZhenan Bao

Research output: Contribution to journalArticlepeer-review


Recent advances in electrodes for noninvasive recording of electroencephalograms expand opportunities collecting such data for diagnosis of neurological disorders and brain-computer interfaces. Existing technologies, however, cannot be used effectively in continuous, uninterrupted modes for more than a few days due to irritation and irreversible degradation in the electrical and mechanical properties of the skin interface. Here we introduce a soft, foldable collection of electrodes in open, fractal mesh geometries that can mount directly and chronically on the complex surface topology of the auricle and the mastoid, to provide highfidelity and long-term capture of electroencephalograms in ways that avoid any significant thermal, electrical, or mechanical loading of the skin. Experimental and computational studies establish the fundamental aspects of the bending and stretching mechanics that enable this type of intimate integration on the highly irregular and textured surfaces of the auricle. Cell level tests and thermal imaging studies establish the biocompatibility and wearability of such systems, with examples of high-quality measurements over periods of 2 wk with devices that remain mounted throughout daily activities including vigorous exercise, swimming, sleeping, and bathing. Demonstrations include a text speller with a steadystate visually evoked potential-based brain-computer interface and elicitation of an event-related potential (P300 wave).

Original languageEnglish (US)
Pages (from-to)3920-3925
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number13
StatePublished - Mar 31 2015


  • Auricle integration
  • Brain-computer interface
  • Soft electronics
  • Text speller

ASJC Scopus subject areas

  • General


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