Metal Painting by Plasma Jet

Conducting metal interconnections are essential to link electronic components or multiple circuits for electronic device fabrication. Scalable, rapid, and sustainable methods for printing adherent metal interconnections on dielectric materials are lacking, which stifles the development of new electronic consumer devices. Here a breakthrough single-step and rapid process to deposit highly conducting metal tracks is introduced, using an atmospheric pressure plasma jet. The deposition process used a rudimentary aqueous solution of metal salts as ink, that was introduced as a mist into a helium plasma gas. The metal salt was reduced and deposited with spatiotemporal control using a plasma jet generated at radio frequency with 15 W power at room temperature and pressure. The conductive metal layers were highly adhesive on glass, ceramics, polymeric materials, even biological surfaces such as plant leaves and animal skin, depostedwith little damage to the substrate. The conductivity of deposited tracks on glass shows 50.8 ± 8.6% and 5.2 ± 1.6% of bulk silver and copper metal conductivity respectively

Correction: Rapid single step atmospheric pressure plasma jet deposition of a SERS active surface

Correction for ‘Rapid single step atmospheric pressure plasma jet deposition of a SERS active surface’ by Oliver S. J. Hagger et al., Mater. Adv., 2023, 4, 3239–3245, https://doi.org/10.1039/D3MA00249G. The authors regret that in the Results and discussion section, the particle sizes for PSNP and PDS particles were given in reversed order. The correct particle sizes should be as follows: On average, through analysis of SEM images, PSNP and PDS particles are 51 ± 24 nm, and 42 ± 12 nm in size, respectively, whereas the commercial substrates OI and SS are 242 ± 58 nm and 133 ± 32 nm in size. The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers

Rapid single step atmospheric pressure plasma jet deposition of a SERS active surface

A helium gas atmospheric pressure plasma jet (APPJ) is used to prepare a silver-based SERS substrate. The Raman enhancement from substrates created using APPJ compares well with two commercially available silver-based SERS substrates and an in-house prepared physical deposition of pre-synthesised silver nanoparticles. An aqueous solution of rudimentary silver salt was required as an ink to deposit zero valent silver in a single step with no post processing. An array of 16 × 16 silver ‘islands’ are printed on borosilicate glass, each island taking 5 seconds to print with a power of < 14 W to sustain the plasma. The SERS response was assessed using 4-mercaptobenzoic acid and rhodamine 6G as model analytes, with a calculated detection limit of 1 × 10−6 M. Also demonstrated is the removal of analyte from the surface after Raman measurement by exposure to helium APPJ doped with oxygen followed by hydrogen to restore zero baseline. This regeneration takes less than 10 seconds and allows for replicate measurements using the same SERS substrate

Gas phase electrochemical detection of single latex particles

n this study we describe zero current potentiometric measurements in a gaseous flame electrolyte, for the detection of single latex particles. Combustion of polystyrene latex particles when added to a premixed hydrogen/oxygen/nitrogen flame, results in an increase in charged species relative to the surrounding hydrogen flame. As a consequence of this increase in ionic concentration over background, short-lived potential difference transients were measured between two platinum indicator electrodes placed in a two-compartment flame electrochemical cell (described in Electrochem. Commun., 2001, 3, 675-681). The frequency of the transient events was dependent on the number density of latex particles in solution. It is proposed that each short-lived transient event corresponds to the combustion of single latex particles in a flame. A potential difference maximum of 0.56 V when 3.0 microm diameter particles were added to the flame was measured. Also it was shown that it is possible to detect 0.3 microm diameter latex particles using the same technique. It is postulated that the physical basis of the potential difference is due to the establishment of diffusion/junction potential due to the increase in ionisation from polystyrene combustion at the surface of one indicator electrode. This methodology may be applied to the detection of particulates composed of ionisable species (organic or inorganic) in gaseous environment such as bacteria, viruses, pollen grains and dust

Modulation of copper(I) oxide reduction/oxidation in atmospheric pressure plasma jet

We describe the controlled reduction of copper(I) oxide films to metallic copper in a non-thermal, atmospheric pressure, helium plasma jet. Thin layers (≈0.1 μm) of Cu2O are electrochemically deposited onto Pt electrodes and placed in capacitively coupled helium plasma doped with H2, O2 or CH4 gases. Ex situ Raman spectroscopy was used to probe the effect of plasma treatment on the deposited copper oxide layer. We show that application of a static bias voltage to the Pt substrate during plasma exposure can control the rate of reduction of the copper(I) oxide film. We propose that the reduction process is mediated by plasma electrons and controlling the electron flux to the surface can be used as a means to modulate the reduction process. Keywords: Copper(I) oxide, Reduction, Atmospheric pressure, Plasma jet, Gaseous electrod