title: Compliment Graphene Oxide Coating on Silk Fiber Surface via Electrostatic Force for Capacitive Humidity Sensor Applications.
abstract: Cylindrical silk fiber (SF) was coated with Graphene oxide (GO) for capacitive humidity sensor applications. Negatively charged GO in the solution was attracted to the positively charged SF surface via electrostatic force without any help from adhesive intermediates. The magnitude of the positively charged SF surface was controlled through the static electricity charges created on the SF surface. The GO coating ability on the SF improved as the SF's positive charge increased. The GO-coated SFs at various conditions were characterized using an optical microscope, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, and LCR meter. Unlike the intact SF, the GO-coated SF showed clear response-recovery behavior and well-behaved repeatability when it was exposed to 20% relative humidity (RH) and 90% RH alternatively in a capacitive mode. This approach allows humidity sensors to take advantage of GO's excellent sensing properties and SF's flexibility, expediting the production of flexible, low power consumption devices at relatively low costs.
authors.affiliation: Department of Materials Engineering, Korea Aerospace University, Goyang 10540, Korea. kooookin@gmail.com.
authors.forename: Kook In
authors.initials: KI
authors.lastname: Han
authors.affiliation: Department of Materials Engineering, Korea Aerospace University, Goyang 10540, Korea. seungdukim@gmail.com.
authors.forename: Seungdu
authors.initials: S
authors.lastname: Kim
authors.affiliation: Department of Materials Engineering, Korea Aerospace University, Goyang 10540, Korea. leeig@kau.ac.kr.
authors.forename: In Gyu
authors.initials: IG
authors.lastname: Lee
authors.affiliation: Division of High Technology Materials Research & Molecular Materials Research Team, Korea Basic Science Institute, Busan 168-230, Korea. jpkim@kbsi.re.kr.
authors.forename: Jong Pil
authors.initials: JP
authors.lastname: Kim
authors.affiliation: Division of High Technology Materials Research & Molecular Materials Research Team, Korea Basic Science Institute, Busan 168-230, Korea. jhkim08@kbsi.re.kr.
authors.forename: Jung-Ha
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Cogno-Mechatronics Engineering, Department of Optics and Mechatronics Engineering, College of Nanoscience and Nanotechnology, Pusan National University, Busan 46241, Korea. swhong@pusan.ac.kr.
authors.forename: Suck Won
authors.initials: SW
authors.lastname: Hong
authors.affiliation: Department of Electrical Engineering, KAIST, Daejeon 34141, Korea. bjcho@kaist.edu.
authors.forename: Byung Jin
authors.initials: BJ
authors.lastname: Cho
authors.affiliation: Department of Materials Engineering, Korea Aerospace University, Goyang 10540, Korea. whwang@kau.ac.kr.
authors.forename: Wan Sik
authors.initials: WS
authors.lastname: Hwang
keywords: capacitive sensor; electrostatic force; graphene oxide coating; humidity sensor