John Fyson

Diffraction grating with suppressed zero order fabricated using dielectric forces

An electric-field-assisted method to produce diffractive optical devices is demonstrated. A uniform film of liquid UV curable resin was produced as a drying ring from an organic solvent. Dielectrophoresis forces maintained the stability of the thin film and also imprinted a periodic corrugation deformation of pitch 20 μm on the film surface. Continuous in situ voltage-controlled adjustment of the optical diffraction pattern was carried out simultaneously with UV curing. A fully cured solid phase grating was produced with the particular voltage-selected tailored optical property that the zero transmitted order was suppressed for laser light at 633 nm.

Fabrication and characterisation of energy storage fibres

Fibre supercapacitors were designed and manufactured using a dip coating method. Their electrochemical properties were characterised using a VersaSTAT 3 workstation. Chinese ink with a fine dispersion of carbon and binder was coated as the electrode material. The specific capacitance per unit length of a copper fibre supercapacitor with the length of 41 cm reached 34.5 mF/cm. When this fibre supercapacitor was bent on rods with a diameter of 10.5 cm, the specific capacitance per length was 93% of the original value (without bending). It proved that these fibre supercapacitors have a good flexibility and energy storage capacity.

A study of 3D printed flexible supercapacitors onto silicone rubber substrates

The rapid development of flexible energy storage devices is crucial for various electronics industries. Highly flexible electrochemical double layer capacitors (EDLCs) can be manufactured by 3D printing technology. It was a great challenge to fabricate multiple material layers of the EDLC in one rapid and accurate deposition event. The fabricated structures were composed of twelve electrodes which could be configured in a number of different ways in one block module. This work aims to investigate the performance of the flexible EDLCs manufactured by 3D printing in a honeycomb pattern. The EDLC cells were fabricated using a slurry made from commercial activated carbon (AC) and a gel electrolyte deposited on a transparent silicone substrate. The flexible EDLCs structures can be used in flexible electronics with different patterns and sizes using 3D printer and can be applied to many applications such as wearable technology.

A study of the electrochemical performance of strip supercapacitors under bending conditions

The European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 281063

Fabrication and characterization of smart fabric using energy storage fibres

Fibre supercapacitors were designed and manufactured using a dip-coating method. Their electrochemical properties were characterized using a VersaSTAT 3 workstation. Chinese ink with a fine dispersion of carbon and binder was coated as the electrode material. The specific capacitance per unit length of a copper fibre supercapacitor with the length of 41 cm reached 34.5 mF/cm. When this fibre supercapacitor was bent on rods with a diameter of 10.5 cm, the specific capacitance per length was 93% of the original value (without bending). It showed that these fibre supercapacitors have good flexibility and energy storage capacity. Furthermore, the fibre supercapacitor in the fabric showed the same capacitance before and after weaving.

Development of 3D printing technology for the manufacture of flexible electric double-layer capacitors

ABSTRACT This study presents a novel process and manufacturing system for the fabrication of Electric Double-Layer Capacitors (EDLCs) as energy storage devices. It shows an approach for printing multilayer EDLC components using 3D printing technology. This process allows layers of activated carbon (AC) slurry, gel electrolyte, and composite solid filaments to be printed with high precision. The study describes the detailed process of deposition of the AC and gel electrolyte using the dual nozzle system. The performance of the flexible EDLCs manufactured by 3D printing in a rectilinear infill pattern has been investigated. It describes the energy storage performance of the printed supercapacitors in relation to the differences in thickness of the AC printed layers and the differences in density of gel electrolyte. A supercapacitor based on printed AC and composite materials displays a specific capacitance of 38.5 mF g−1 when measured at a potential rate change of 20 mV s−1 and a current density of 0.136 A g−1. The highest energy density value for the flexible EDLC was 0.019 Wh kg−1 and power density of 165.0 W kg−1 in 1.6 M H2SO4/PVA gel electrolyte.

A study of the electrochemical performance of strip supercapacitors under static and dynamic mechanical tests

This work was supported by the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 281063.

A manufacturing process for an energy storage device using 3D printing

3D printing has been widely applied in the development of prototypes. The main advantage of this process is that the objects or products can be viewed in three dimensions on a computer display and a 3D sample can be created before committing to a large production run. There are various 3D printing technologies that are capable of manufacturing metal, ceramic, plastic substrate and paste objects. Recently several research groups have focused on the fabrication freedom of 3D printing for different purposes including freeform manufacturing of electrochemical devices but this use is still limited. This paper describes a manufacturing process for electrochemical supercapacitors using the combination of the two techniques of 3D printing which are Fused Deposition Modelling (FDM) and a Paste Extrusion system. The method relies on creating a frame for the energy storage device, i.e. supercapacitor, by the FDM 3D printer and then depositing the conductive layers and electrodes of the supercapacitor using Paste Extrusion system. A 3D supercapacitor has been made and evaluated in this study.

A study of the performance of the combination of energy storage fibres

Fibre supercapacitors were manufactured using a motor-driven setup. Their electrochemical properties were characterised. The performance of two fibre supercapacitors in series or in parallel mainly followed the expected theoretical models. The electrochemical potential window of a series circuit of two fibre supercapacitors is 1.6 V, which is twice of the working potential of the individual fibre supercapacitors, and the charge-discharge current of two fibre supercapacitors in parallel is also twice of the current for a single one.