title: A Fully Transparent Flexible Sensor for Cryogenic Temperatures Based on High Strength Metallurgical Graphene.
abstract: Low-temperature electronics operating in below zero temperatures or even below the lower limit of the common -65 to 125 °C temperature range are essential in medical diagnostics, in space exploration and aviation, in processing and storage of food and mainly in scientific research, like superconducting materials engineering and their applications-superconducting magnets, superconducting energy storage, and magnetic levitation systems. Such electronic devices demand special approach to the materials used in passive elements and sensors. The main goal of this work was the implementation of a fully transparent, flexible cryogenic temperature sensor with graphene structures as sensing element. Electrodes were made of transparent ITO (Indium Tin Oxide) or ITO/Ag/ITO conductive layers by laser ablation and finally encapsulated in a polymer coating. A helium closed-cycle cryostat has been used in measurements of the electrical properties of these graphene-based temperature sensors under cryogenic conditions. The sensors were repeatedly cooled from room temperature to cryogenic temperature. Graphene structures were characterized using Raman spectroscopy. The observation of the resistance changes as a function of temperature indicates the potential use of graphene layers in the construction of temperature sensors. The temperature characteristics of the analyzed graphene sensors exhibit no clear anomalies or strong non-linearity in the entire studied temperature range (as compared to the typical carbon sensor).
authors.affiliation: Institute of Electrical Engineering Systems, Lodz University of Technology, 90-924 Lodz, Poland. ryszard.pawlak@p.lodz.pl.
authors.forename: Ryszard
authors.initials: R
authors.lastname: Pawlak
authors.affiliation: Institute of Electrical Engineering Systems, Lodz University of Technology, 90-924 Lodz, Poland. marcin.lebioda@p.lodz.pl.
authors.forename: Marcin
authors.initials: M
authors.lastname: Lebioda
authors.affiliation: Institute of Electrical Engineering Systems, Lodz University of Technology, 90-924 Lodz, Poland. jacek.rymaszewski@p.lodz.pl.
authors.forename: Jacek
authors.initials: J
authors.lastname: Rymaszewski
authors.affiliation: Institute of Materials Science and Engineering, Lodz University of Technology, 90-924 Lodz, Poland. witold.szymanski@p.lodz.pl.
authors.forename: Witold
authors.initials: W
authors.lastname: Szymanski
authors.affiliation: Institute of Materials Science and Engineering, Lodz University of Technology, 90-924 Lodz, Poland. lukasz.kolodziejczyk@p.lodz.pl.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Kolodziejczyk
authors.affiliation: Institute of Materials Science and Engineering, Lodz University of Technology, 90-924 Lodz, Poland. piotr.kula@p.lodz.pl.
authors.forename: Piotr
authors.initials: P
authors.lastname: Kula
keywords: cryogenic; graphene; low-temperature; sensors