Modeling Electrochemical Impedance Spectroscopy Using Time-Dependent Finite Element Method.

A time-dependent electrochemical impedance spectroscopy (EIS) model is presented using the finite element method (FEM) to simulate a 2D interdigitated electrode in an aqueous NaCl electrolyte. Developed in COMSOL Multiphysics, the model incorporates ion transport, electric field distribution, Stern layer effects, and electrode sheet resistance, governed by the Poisson and Nernst-Planck equations. This model can predict the transient current response to an applied excitation voltage, which gives information about the dynamics of the electrochemical system.

Estimating the proportion of overweight soldiers in the Australian Army by combat uniform waist size.

Introduction: Recent studies have shown an increasing number of overweight and obese members serving in many armies. Overweight and obesity can be estimated using either body mass index or waist circumference measures. The aim of this research was to estimate the proportion of the Australian Army considered to be overweight and obese by waist circumference using the proxy measure of issued combat uniform waist size.

Fast Procedures for the Electrodeposition of Platinum Nanostructures on Miniaturized Electrodes for Improved Ion Sensing.

Nanostructured materials have attracted considerable interest over the last few decades to enhance sensing capabilities thanks to their unique properties and large surface area. In particular, noble metal nanostructures offer several advantages including high stability, non-toxicity and excellent electrochemical behaviour. However, in recent years the great expansion of point-of-care (POC) and wearable systems and the attempt to perform measurements in tiny spaces have also risen the need of increasing sensors miniaturization.

Electrochemical sensing of ethylene employing a thin ionic-liquid layer.

We introduce an electrochemical ethylene sensor that employs a thin layer of ionic liquid as electrolyte. Ethylene is oxidized in a potential window starting ∼600 mV before the onset of the gold working electrode oxidation, which inhibits the ethylene oxidation at high applied potential. The current amplitude and sensor response time depend on the ionic-liquid film thickness, relative humidity, and applied potential, in agreement with a theoretical model based on diffusion.

Stochastic sensing of single molecules in a nanofluidic electrochemical device.

We report the electrochemical detection of individual redox-active molecules as they freely diffuse in solution. Our approach is based on microfabricated nanofluidic devices, wherein repeated reduction and oxidation at two closely spaced electrodes yields a giant sensitivity gain. Single molecules entering and leaving the cavity are revealed as anticorrelated steps in the faradaic current measured simultaneously through the two electrodes.