Deposition of graphene and related nanomaterials by dynamic spray-gun method: a new route to implement nanomaterials in real applications

Abstract

The dynamic spray-gun deposition method was developed in 2006 to fabricate field effect transistors based on random arrays of carbon nanotubes (CNTs) field effect transistors for gas sensing applications. Thanks to this deposition method, we were able to fabricate hundreds of operational devices in a reproducible way that were integrated in electronic chips. Following this first implementation, we decided to widen the application of the deposition technique to the field of Energy and specifically to the fabrication of supercapacitors. In this context, we demonstrated in 2012 the fabrication of nanostructured electrodes for supercapacitors, using mixtures of graphene/graphite and CNTs increasing the device capacitance and the power delivered of a factor 2.5 compared to CNT based electrochemical-double-layer-capacitors. Indeed, with high quality graphene we could reach a value of around 100 W Kg −1 . This value is extremely promising also considering that it has been obtained with an industrially suitable technique. This dynamic spray-gun deposition has been also exploited for the fabrication of resistance based random access memories, making use of thin layers of graphene oxide and of oxidized carbon nanofibers. In the first case, 5000 cycles of 'write' and 'read' phases were demonstrated. These results pave the way for the fabrication of very low cost memories that can be embedded in smart-cards, patches for health monitoring (e.g. diabetes), ID cards, RFID tags and more generally smart packaging. Finally we are also working on the utilization of this technique for the fabrication of layers for electro-magnetic interference shielding application. Thanks to a new machine with four nozzles, developed within the frame of the Graphene Flagship project, we are able to deposit four different nanomaterials at the same time or alternatively on a large surface (30 cm×30 cm) creating specific nano-structuration and therefore ad hoc architectures allowing the smart absorption of specific frequencies (e.g. X-band). All these applications demonstrate the extreme versatility of this technique that constitutes a real breakthrough for exploiting the nanomaterials characteristics in real devices, using an industrial suitable fabrication method that can be implemented using roll-to-roll technique.

Graphene‐Enabled Electrophoretic Ion Pump Delivery Devices

“…GO films of ≈130 nm thickness were deposited using a spray‐gun technique on plain polyethylene terephthalate (PET) as well as on PET substrates pre‐coated with PEDOT:PSS. [ 34 ] Scanning electron microscopy (SEM) and atomic force microscopy (AFM) showed that the morphology of the as‐deposited GO layers is practically identical for both substrates. Therefore, only GO films on PET were considered in the following work.…”

“…For the preparation of the films, a spray‐gun technique was used. [ 34 ] PET and PEDOT:PSS/PET substrates (4–5 mm × 5–6 cm) used were placed on a hotplate set at 80 °C. The PEDOT:PSS/PET substrate was used as a control for investigating the adhesion and morphology of the films attained compared to those on the plain PET substrate.…”

Liquid‐Exfoliated 2D Materials for Optoelectronic Applications

“…[250,268] One form of spray-coating method, the dynamic spray-gun method, has been used to deposit graphene and its composites with other nanomaterials for various electronic and energy devices, including supercapacitors and random access memories. [269]…”

High-surface-area activated carbon from pine cones for semi-industrial spray deposition of supercapacitor electrodes

“…45,46 The spray-gun is moved in the X-Y plane and the nozzle height over the substrate can be finely adjusted. The deposition is taking place in lines with length of 30cm and with a pitch of around 1cm to allow the best recovery of the sprayed cones 47 on a total width of 10cm. The precision for all the movements is around 100 μm.…”