Bioinspired Heat‐Induced Viscoelasticity‐Switchable Electrodes for Conformal Brain‐Computer Interfaces
Abstract
ABSTRACT Electroencephalography is a promising noninvasive modality for brain‐computer interfaces (BCIs), yet its widespread adoption is constrained by electrode limitations: dry electrodes yield unstable signals, whereas wet electrodes require laborious setup and are ill‐suited to wearable devices. Inspired by honeybees that locally heat beeswax to reversibly switch it between rigid and moldable states for comb construction, this work introduces a heat‐induced viscoelasticity‐switchable electrode (HIVE) that enables conformal contact on hairy scalps and user‐friendly operation in wearable systems. HIVE integrates a thermoresponsive gelatin gel confined in a sponge matrix with an on‐electrode microheater. Its temperature is actively modulated on demand, enabling autonomous switching between the gel and sol states. As a flowable sol, it permeates hair, conforms to the skin. At body temperature, it remains in a viscoelastic state, providing strong adhesion. Moreover, heating duration is closed‐loop controlled using real‐time electrode‐skin impedance. In steady‐state visual evoked potential paradigm, HIVE delivers high classification accuracy comparable to gold‐standard wet electrodes while supporting wearable BCI devices for vision‐based wheelchair navigation and high‐speed text entry. By translating honeybee viscoelasticity‐modulation strategy into bioelectronic interfaces, this work provides a practical solution for wearable BCI devices and a new design paradigm for conformal biointerfaces on hairy or piliferous surfaces.
Article Details
Authors (12)
Zheren Cai
Innovative Centre For Flexible Devices (iFLEX) Max Planck–NTU Joint Lab for Artificial Senses School of Materials Science and Engineering Nanyang Technological University Singapore Singapore
Shangen Zhang
College of Computing and Data Science Nanyang Technological University Singapore Singapore
Jianwu Wang
Institute for Digital Molecular Analytics and Science (IDMxS), Nanyang Technological University, 59 Nanyang Drive, Singapore 636921, Singapore
Yifei Luo
Institute of Materials Research and Engineering (IMRE) Agency for Science Technology and Research (A*STAR) Singapore Singapore
Ming Zhu
State Key Laboratory of Physical Chemistry of Solid Surfaces, Key Laboratory for Chemical Biology of Fujian Province, The MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, Department of Chemical Biology, College of Chemistry and Chemical Engineering, State Key Laboratory of Vaccines for Infectious Diseases, Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, School of Life Sciences, Faculty of Medicine and Life Sciences
Zhisheng Lv
Institute of Materials Research and Engineering, Agency for Science, Technology and Research (A*STAR), 2 Fusionopolis Way, Innovis, Singapore 138634, Singapore
Xiaoyang Li
Yuzhen Chen
Yonghao Song
School of Biomedical Engineering Tsinghua University Beijing P. R. China
XiaoRong Gao
Cuntai Guan
College of Computing and Data Science Nanyang Technological University Singapore Singapore
Xiaodong Chen
Innovative Centre for Flexible Devices (iFLEX), Max Planck-NTU Joint Lab for Artificial Senses, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Republic of Singapore