title: Bioinspired, Highly Stretchable, and Conductive Dry Adhesives Based on 1D-2D Hybrid Carbon Nanocomposites for All-in-One ECG Electrodes.
abstract: Here we propose a concept of conductive dry adhesives (CDA) combining a gecko-inspired hierarchical structure and an elastomeric carbon nanocomposite. To complement the poor electrical percolation of 1D carbon nanotube (CNT) networks in an elastomeric matrix at a low filler content (∼1 wt %), a higher dimensional carbon material (i.e., carbon black, nanographite, and graphene nanopowder) is added into the mixture as an aid filler. The co-doped graphene and CNT in the composite show the lowest volume resistance (∼100 ohm·cm) at an optimized filler ratio (1:9, total filler content: 1 wt %) through a synergetic effect in electrical percolation. With an optimized conductive elastomer, gecko-inspired high-aspect-ratio (>3) microstructures over a large area (∼4 in.(2)) are successfully replicated from intaglio-patterned molds without collapse. The resultant CDA pad shows a high normal adhesion force (∼1.3 N/cm(2)) even on rough human skin and an excellent cycling property for repeatable use over 30 times without degradation of adhesion force, which cannot be achieved by commercial wet adhesives. The body-attachable CDA can be used as a metal-free, all-in-one component for measuring biosignals under daily activity conditions (i.e., underwater, movements) because of its superior conformality and water-repellent characteristic.
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea.
authors.forename: Taehoon
authors.initials: T
authors.lastname: Kim
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea.
authors.forename: Junyong
authors.initials: J
authors.lastname: Park
authors.affiliation: Wearable Computing Research Team, ETRI , Daejeon 34129, Republic of Korea.
authors.forename: Jongmoo
authors.initials: J
authors.lastname: Sohn
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea.
authors.forename: Donghwi
authors.initials: D
authors.lastname: Cho
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, KAIST , Daejeon 34141, Republic of Korea.
authors.forename: Seokwoo
authors.initials: S
authors.lastname: Jeon
mesh_terms: D000269:Adhesives / Q000737:chemistry*; D004548:Elasticity; D020724:Elastomers / Q000737:chemistry; D004553:Electric Conductivity; D004562:Electrocardiography / Q000295:instrumentation*; D055664:Electrochemical Techniques / Q000379:methods; D004566:Electrodes; D006108:Graphite / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D053761:Nanocomposites / Q000737:chemistry*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010316:Particle Size; D016062:Porosity; D012867:Skin / Q000378:metabolism; D013499:Surface Properties
chemical_list: D000269:Adhesives; D020724:Elastomers; D037742:Nanotubes, Carbon; D006108:Graphite
keywords: ECG electrodes; biomimetics; conductive dry adhesives; nanocomposites; stretchable conductors