Electrospray: A Suitable Technique for Carbon-based Rigid and Flexible Devices
Albert Cornet, Aïda Varea, Omar Olmedo, Oriol Monereo, J. Daniel Prades, Albert Cirera
MIND-IN2UB, Departament d’Enginyeries: Electrònica, Facultat de Física, Universitat de
Barcelona, Martí i Franquès 1, 08028, Barcelona, Spain
Carbon-based materials are the trendiest materials since Geim and Novoselov
1
discovered
graphene in 2004. The implementation of these materials onto light, flexible and wearable
substrates is an important drawback due to the transfer techniques often used involve
complex processes and expensive steps. In this sense electrospray is proposed to overcome
this issue.
Electrospray is an old and well know deposition technique often used for metallic and
polymeric film coatings. Electrospray deposition (ESD) technique stands out from all
conventional deposition techniques because it can work under room temperature and ambient
pressure, i.e. it does not require vacuum and high temperature equipment, it is industrially
scalable, and a wide variety of substrates can be used (rigid like Si and glass or flexible like
polyimide).
Recent advances in our group
2-4
have shown the feasibility to use this technique to deposit
carbon-based materials: graphene-oxide (GO), reduced graphene oxide (rGO) and carbon
nanofibers (CNF)
5
. Then, the aim of this work is two-fold: in one hand, GO, rGO and CNF
dispersions properties (concentration, viscosity, conductivity) are analysed and correlated
with the deposition parameters to obtain the optimized deposition conditions. One of the most
important points is that no surfactants or additives have been used that points that EDS of
carbon-based materials can be used for biological systems. On the other hand, it will be
demonstrated that electrospray is a feasible and reliable technique to deposit small- and large-
areas of graphene-based materials with a good thickness control and spatial resolution. The
possibility to use masks to limit the deposition area, allows localized coatings onto electronic
devices preserving non-desired coated zones. Then, deposits of GO, rGO and CNF with
different sizes and geometries onto different substrates (silicon, glass, FTO coated glass, PET
and polyimide) are presented and some of their properties analysed (thickness, optical
transmittance and electrical conductivity).
Finally it will be demonstrated that electrospray is a suitable technique to deposit carbon
nanofibers onto functional flexible substrates. As example, devices such as sensors will be
shown.
[1] A.K. Geim, K.S. Novoselov, Nat. Mater. 6 (2007), 183−191.
[2] A. Varea, E. Xuriguera, B. Medina, S. Claramunt, O. Monereo, A. Cirera, “Electrospray: A Novel Technique for Carbon-
based Flexible Devices” in E-MRS Meeting (2014) Lille.
[3] E. Xuriguera, O. Monereo, A. Varea, A. Cirera, “Flexible reduced graphene oxide gas sensor deposited by electrospray,”
in
Proceedings 15th Trends in Nanotechnology International Conference
, (2014) Barcelona.
[4] O. Olmedo, G. Vescio, A. Varea, A. Cornet, A. Cirera, “Light technologies towards graphene devices” in ICREA
Workshop on Graphene Biosensors (2015) Barcelona.
[5] S. Claramunt, O.Monereo, M. Boix, R. Leghrib, J.D. Prades, A. Cornet, P. Merino, C. Merino, A. Cirera, Sensors and
actuators B: Chemical, 187 (2013), 401-406.
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