resumo
Graphene-coated polypropylene (PP) textile fibers are presented for their use as temperature sensors. These temperature sensors show a negative thermal coefficient of resistance (TCR) in a range between 30 and 45 degrees C with good sensitivity and reliability and can operate at voltages as low as 1 V. The analysis of the transient response of the temperature on resistance of different types of graphene produced by chemical vapor deposition (CVD) and shear exfoliation of graphite (SEG) shows that trilayer graphene (TLG) grown on copper by CVD displays better sensitivity due to the better thickness uniformity of the film and that carbon paste provides good contact for the measurements. Along with high sensitivity, TLG on PP shows not only the best response but also better transparency, mechanical stability, and washability compared to SEG. Temperature-dependent Raman analysis reveals that the temperature has no significant effect on the peak frequency of PP and expected effect on graphene in the demonstrated temperature range. The presented results demonstrate that these flexible, lightweight temperature sensors based on TLG with a negative TCR can be easily integrated in fabrics.
palavras-chave
WEARABLE E-TEXTILE; ELECTRICAL-PROPERTIES; DEPENDENCE
categoria
Science & Technology - Other Topics; Materials Science
autores
Rajan, G; Morgan, JJ; Murphy, C; Alonso, ET; Wade, J; Ott, AK; Russo, S; Alves, H; Craciun, MF; Neves, AIS
nossos autores
Ana Isabel Soares Neves
Bolseiro de pós-Doutoramento
Helena Alves
Investigador PrincipalProjectos
Single Crsytal Solar Cell (IF/01088/2014)
Sensores de temperatura, gases e humidade baseados em grafeno para a eletronica têxtil (Graphsense)
agradecimentos
The authors acknowledge financial support from the European Commission for project. E-TEX., H2020-MSCA-IF-2015-704963, EPSRC grant EP/S019855/1 and EP/M001024/1; the College of Engineering Mathematics and Physical Sciences, University of Exeter for the PhD studentship; and the Portuguese Foundation for Science and Technology grants IF/01088/2014, UIDB/50011/2020, and POCI-01-0145-FEDER-032072. G.R. and A.N. would like to thank Mr. Fred Rose for the sensor sketch and Ms. Catherine Edington and Ms. Saskia Sherwood for the assistance with washing tests. We would like to thank Dr. Peter Armitage for producing the measuring setup for the electrical conductivity measurements, Dr. Ellen M. Green for the help with the Raman mapping, Dr. Isabel de Schrijver for providing the PP fibers, Mr. Mark Heath for his assistance in the clean room, and Dr. Hong Chang for the assistance with SEM imaging. We would like to express our gratitude to Prof Ji-Seon Kim for the use of the temperaturedependent Raman system.