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Changing the connection length of an additively manufactured electrode (AME) has a significant impact on the electrochemical and electroanalytical response of the system. In the literature, many electrochemical platforms have been produced using additive manufacturing with great variations in how the AME itself is described. It is seen that when measuring the near-ideal outer-sphere redox probe hexaamineruthenium (III) chloride (RuHex), decreasing the AME connection length enhances the heterogeneous electrochemical transfer (HET) rate constant ( k 0 ) for the system. At slow scan rates, there is a clear change in the peak-to-peak separation (ΔEp) observed in the RuHex voltammograms, with the ΔEp shifting from 118 ± 5 mV to 291 ± 27 mV for the 10 and 100 mm electrodes, respectively. For the electroanalytical determination of dopamine, no significant difference is noticed at low concentrations between 10- and 100-mm connection length AMEs. However, at concentrations of 1 mM dopamine, the peak oxidation is shifted to significantly higher potentials as the AME connection length is increased, with a shift of 150 mV measured. It is recommended that in future work, all AME dimensions, not just the working electrode head size, is reported along with the resistance measured through electrochemical impedance spectroscopy to allow for appropriate comparisons with other reports in the literature. To produce the best additively manufactured electrochemical systems in the future, researchers should endeavor to use the shortest AME connection lengths that are viable for their designs. [ABSTRACT FROM AUTHOR]

In this work, the electrochemical response of different morphologies (shapes) and dimensions of additively manufactured (3D-printing) carbon black (CB)/poly-lactic acid (PLA) electrodes are reported. The working electrodes (WE) are printed using standard non-conductive PLA based filament for the housing and commercial Protopasta (carbon black/PLA) filament for the electrode and connection parts. Discs, squares, equilateral triangles and six-point stars with varying working electrode (WE) widths from 2 to 10 mm are evaluated herein towards the well-known near-ideal outer sphere redox probe hexaamineruthenium(III) chloride (RuHex). The results obtained show that triangular and squared electrodes exhibit a faster heterogeneous electron transfer (HET) rate constant (k°) than those of discs and stars, the latter being the slowest one. The results reported here also show a trend between the WE dimension and the reversibility of the electrochemical reaction, which decreases as the WE size increases. It is also observed that the ratio of the geometrical and electroactive area (%realarea) decreases as the overall WE size increases. On the other hand, these four WE shapes were applied toward the well-known and benchmarking detection of ascorbic acid (AA), uric acid (UA), β-nicotinamide adenine dinucleotide (NADH) and dopamine (DA). Moreover, electroanalytical detection of real acetaminophen (ACOP) samples is also showcased. The different designs for the working electrode proposed in this manuscript are easily changed to any other desired shapes thanks to the additive manufacturing methodology, these four shapes being just an example of what additive manufacturing can offer to experimentalists and to electrochemists in particular. Additive manufacturing is shown here as a versatile and rapid prototyping tool for the production of novel electrochemical sensing platforms, with scope for this work to be able to impact a wide variety of electroanalytical applications. [ABSTRACT FROM AUTHOR]

Herein, we report the fabrication and application of Li‐ion anodes for utilisation within Li‐ion batteries, which are fabricated via additive manufacturing/3D printing (fused deposition modelling) using a bespoke graphene/polylactic acid (PLA) filament, where the graphene content can be readily tailored and controlled over the range 1–40 wt. %. We demonstrate that a graphene content of 20 wt. % exhibits sufficient conductivity and critically, effective 3D printability for the rapid manufacturing of 3D printed freestanding anodes (3DAs); simplifying the components of the Li‐ion battery negating the need for a copper current collector. The 3DAs are physicochemically and electrochemically characterised and possess sufficient conductivity for electrochemical studies. Critically, it is found that if the 3DAs are used in Li‐ion batteries the specific capacity is very poor but can be significantly improved through the use of a chemical pre‐treatment. Such treatment induces an increased porosity, which results in a 200‐fold increase (after anode stabilisation) of the specific capacity (ca. 500 mAh g−1 at a current density of 40 mA g−1). This work significantly enhances the field of additive manufacturing/3D printed graphene based energy storage devices demonstrating that useful 3D printable batteries can be realised. [ABSTRACT FROM AUTHOR]

The development and increase in the number of crops recently have led to the requirement for greater efficiency in world food production and greater consumption of pesticides. In this context, the widespread use of pesticides has affected the decrease in the population of pollinating insects and has caused food contamination. Therefore, simple, low-cost, and quick analytical methods can be interesting alternatives for checking the quality of foods such as honey. In this work, we propose a new additively manufactured (3D-printed) device inspired by a honeycomb cell, with 6 working electrodes for the direct electrochemical analysis of methyl parathion by reduction process monitoring in food and environmental samples. Under optimized parameters, the proposed sensor presented a linear range between 0.85 and 19.6 μmol L -1 , with a limit of detection of 0.20 μmol L -1 . The sensors were successfully applied in honey and tap water samples by using the standard addition method. The proposed honeycomb cell made of polylactic acid and commercial conductive filament is easy to construct, and there is no need for chemical treatments to be used. These devices based on 6 working electrodes array are versatile platforms for rapid, highly repeatable analysis in food and environment, capable of performing detection in low concentrations., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)