Circular Electrodes Research Articles

Silver-Doped Reduced Graphene Oxide/PANI-DBSA-PLA Composite 3D-Printed Supercapacitors.

This study presents a novel approach to the development of high-performance supercapacitors through 3D printing technology. We synthesized a composite material consisting of silver-doped reduced graphene oxide (rGO) and dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PANI), which was further blended with polylactic acid (PLA) for additive manufacturing. The composite was extruded into filaments and printed into circular disc electrodes using fused deposition modeling (FDM). These electrodes were assembled into symmetric supercapacitor devices with a solid-state electrolyte. Electrochemical characterization, including cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) tests, demonstrated considerable mass-specific capacitance values of 136.2 F/g and 133 F/g at 20 mV/s and 1 A/g, respectively. The devices showed excellent stability, retaining 91% of their initial capacitance after 5000 cycles. The incorporation of silver nanoparticles enhanced the conductivity of rGO, while PANI-DBSA improved electrochemical stability and performance. This study highlights the potential of combining advanced materials with 3D printing to optimize energy storage devices, offering a significant advancement over traditional manufacturing methods.

Technical note: Computational study on thermal management schemes for tumor-treating fields therapy.

The study focuses on thermal management in tumor-treating fields (TTFields) therapy, crucial for patient compliance and therapeutic effectiveness. TTFields therapy, an established treatment for glioblastoma, involves applying alternating electric fields to the brain. However, managing the thermal effects generated by electrodes is a major challenge, impacting patient comfort and treatment efficiency. This research aims to explore methods for controlling temperature increases during TTFields therapy without reducing its duty cycle. The study emphasizes optimizing electrode configurations and array arrangements to mitigate temperature rise, thereby maintaining therapy effectiveness and patient compliance. Using a simplified multi-layer tissue model and finite element analysis, various electrode configurations and array shapes were tested in COMSOL Multiphysics v6.0. Adjustments included changing the electrode gel layer radius from 8 to 12mm, electrode spacing, and transitioning to a more uniform array arrangement, such as a square array or a circular array. The study revealed a strong correlation between high temperatures and edge current density distributions on electrodes. It was found that increasing the electrode gel layer's diameter, enlarging electrode spacing, and adopting a uniform array arrangement markedly mitigated temperature rises. By increasing the gel layer radius from the original 10 to 12mm, a reduction in the peak temperature increases of approximately 0.3°C was observed. Changing the layout from rectangular to circular with the same area further reduced the peak temperature rise by 0.5°C. Additionally, enlarging the spacing between electrodes also contributed to temperature control. By integrating these strategies, we designed a new circular electrode array with an electrode spacing of 45mm and a gel radius of 12mm, successfully reducing the peak temperature from 42.1°C to 40.8°C, effectively achieving temperature control. The research demonstrates that improving electrode and array configurations can effectively manage temperature in TTFields therapy without compromising treatment duration. This strategy is crucial as TTFields therapy relies on prolonged field exposure for effectiveness. The findings offer valuable insights into thermal management in electrode array design and could lead to enhanced patient compliance and treatment efficacy in TTFields therapy.

A wafer-level characterization method of thin film transverse piezoelectric coefficient evaluation

Accurate measurement of the piezoelectric property of thin films is critical for thin film process development and device design optimization. In this paper, we proposed a wafer-level thin film characterization method that provides a non-destructive, single-side measurement solution for evaluating and in-process monitoring the transverse piezoelectric coefficient (e31,f). The e31,f of piezoelectric films was determined by measuring the deflection of circular electrode induced by the converse piezoelectric effect, with the electrodes fabricated on top of piezoelectric thin film on a silicon substrate. The constitutive equation of the unimorph plate reveals a quadratic dependence of top electrode deflection (δ) on the radius (r), which was subsequently utilized to calculate the e31,f while considering the electrode edge effect. Determined by non-constant variations of |δ/r2| from finite element method (FEM) simulation results, the electrode edge effect leads to the specification of electrode size and substrate thickness for evaluating piezoelectric coefficient. A comprehensive FEM simulation analysis of the influence of wafer size and electrode location on the accuracy of the proposed method demonstrated its reliability for wafer-level characterization. The e31,f measurement results of single-crystal (s-PZT) and polycrystalline PZT (p-PZT) exhibit good agreement between the proposed wafer-level method and the die-level cantilever method. These results demonstrated that the proposed single-side wafer-level method provides a reliable measurement technique for e31,f characterization of piezoelectric thin film.

Design and Fabrication of High-Performance Piezoelectric Micromachined Ultrasonic Transducers Based on Aluminum Nitride Thin Films.

Ultrasound is widely applied in diverse domains, such as medical imaging, non-destructive evaluation, and acoustic communication. Piezoelectric micromachined ultrasonic transducers (PMUTs) capable of generating and receiving ultrasonic signals at the micrometer level have become a prominent technology in the field of ultrasound. It is important to enrich the models of the PMUTs to meet the varied applications. In this study, a series of PMUT devices featured with various top electrode configurations, square, circular, and doughnut, were designed to assess the influence of shape on the emission efficacy. It was demonstrated that the PMUTs with a circular top electrode were outperformed, which was calculated from the external acoustic pressure produced by the PMUTs operating in the fundamental resonant mode at a specified distance. Furthermore, the superior performance of PMUT arrays were exhibited through computational simulations for the circular top electrode geometries. Conventional microelectromechanical systems (MEMS) techniques were used to fabricate an array of PMUTs based on aluminum nitride (AlN) films. These findings make great contributions for enhancing the signal transmission sensitivity and bandwidth of PMUTs, which have significant potential in non-destructive testing and medical imaging applications.

Пьезоэлектрический дисковый актюатор кручения с дискретно-спиральными электродами

A mathematical model of a disk (ring) torsion actuator with curvilinear interdigital electrodes – «villi» of a spiral form, which are characterized by a constant value of the orientation angle of an arbitrary section of the villus to the circumferential direction of the disk, has been developed. Bases of electrode-villi interacting with each other through local areas of piezoelectric layer are connected with periodic alternation to central or peripheral concentric circular base electrodes, to outputs of which control voltages are connected. As a result of numerical modeling of the «twisting bimorph» graphs of the dependence of the twist angle and the blocking torque on the ratio of the inner and outer radii and the values of the control voltage at the outputs of the base electrodes of the annular two-layer actuator with symmetrical (relative to the radial line) directions of the spiral orientations of the electrode-villi and, as a result, the spiral polarization lines of the piezoelectric layers working for tension/compression.

Study on the Anti-Interference Performance of Substrate-Free PEDOT:PSS ECG Electrodes

Substrate-free electrodes are promising dry electrodes for long-term physiological electrical signal monitoring due to their ultra-thinness, conformal contact, and stable skin–electrode impedance. However, the response of substrate-free electrodes to various disturbances during electrocardiogram (ECG) monitoring and the corresponding optimization needs to be investigated. This paper investigates the specific effects of various influencing factors on skin–electrode impedance and ECG during electrocardiogram (ECG) detection. The research utilizes substrate-free poly(3,4-ethylenedioxythiophene)/poly(styrene-sulfonate) (PEDOT:PSS) electrodes. The investigation employs several methods, including skin–electrode impedance comparison, ECG waveform analysis, spectrum analysis, and signal-to-noise ratio (SNR) evaluation. To avoid the impact of physiological state differences in subjects at different times, relevant data were only compared with the same group of experiments conducted in the same period. The results demonstrate that the substrate-free conformal contact PEDOT:PSS electrode has more stable skin–electrode impedance and could obtain a more stable ECG than partial contact electrodes (the SNR of the partial contact and conformal contact electrodes are 1.2768 ± 4.0299 dB and 7.2637 ± 1.4897 dB, respectively). Furthermore, the ECG signal quality of the substrate-free conformal contact PEDOT:PSS electrode was independent of the electrode area and shape (the SNRs of the large, medium, and small electrodes are 4.0447 ± 0.4616 dB, 3.9115 ± 0.5885 dB, and 4.1556 ± 0.5557 dB, respectively; the SNRs of the circular, square, and triangular electrodes are 9.2649 ± 0.6326 dB, 9.2471 ± 0.6806 dB, and 9.1514 ± 0.6875 dB, respectively), showing high signal acquisition capability that is the same as microneedle electrodes and better than fabric electrodes. The results of clothing friction effects show that skin–electrode impedance stability was important for ECG stability, while the impedance value was not (the SNRs of friction and non-friction electrodes are 2.4128 ± 7.0784 dB and 9.2164 ± 0.6696 dB, respectively). Moreover, the skin–electrode impedance maintains stability even at a high breathing frequency, but the ECG signal fluctuates at a high breathing frequency. This experiment demonstrates that even when the skin–electrode impedance remains stable, the ECG signal can still be susceptible to interference from other factors. This study suggests that substrate-free PEDOT:PSS that could form conformal contact with the skin has higher skin–electrode impedance stability and could measure a high ECG signal even with a small electrode area, demonstrating its potential as dry ECG electrodes, but the interference from other physiological electrical signals may require better circuit design.

Development of optimum performance model during spark-eroded processing of rheocasted Al6061/Cenosphere MMCs

ABSTRACT In the present study, an improved wettability casting route was used to prepare lightweight structural materials. Using the compo casting process, an Al6061 alloy was created with cenosphere particles at various weight percentages (2, 4, 6, and 8 wt%). The molten aluminium slurry incorporated hollow alumina silicate particulates. X-ray diffraction (XRD) analysis of the aluminium matrix composites (AMCs) confirmed the presence of cenospheres without any intermetallic components. Further processing of the metal matrix composites (MMCs) was conducted using electric discharge machining (EDM) with a circular copper electrode. The EDM process parameters were controlled to measure response variables such as material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR). The effects of different combinations of machining parameters – including pulse current, pulse-on time, reinforcement percentage, and flushing pressure – on these performance characteristics were observed. Experimental trials were designed using the face-centred central composite design (CCD) of the response surface methodology (RSM). Optimal process variable conditions led to significant improvements in surface finish. Additionally, an artificial neural network (ANN) model was used to determine the best conditions for EDM processing. The ANN model demonstrated a strong correlation coefficient of 0.99 between the predicted and experimental values of MRR, TWR, and SR.

Comparative Study and Investigation of Homogeneous Soil with Connected Circular and Cylindrical Electrodes Based on Fields Distribution of Direct Lightning Strike on Wind Turbine

Comparative Study and Investigation of Homogeneous Soil with Connected Circular and Cylindrical Electrodes Based on Fields Distribution of Direct Lightning Strike on Wind Turbine

Self-Powered Terahertz Modulators Based on Metamaterials, Liquid Crystals, and Triboelectric Nanogenerators.

6G communication mainly occurs in the THz band (0.1-10 THz), which can achieve excellent performance. Self-powered THz modulators are essential for achieving better conduction, modulation, and manipulation of THz waves. Herein, a self-powered terahertz modulator, which is based on metamaterials, liquid crystals (LCs), and rotary triboelectric nanogenerators (R-TENGs), is proposed to realize the driving of different array elements. The corresponding designs can achieve an integrated design and preparation method for dynamic spectrum-reconfigurable liquid crystal metamaterials. In addition, for the type of cross-structure metamaterial liquid crystal box, a phase modulation of 1 GHz is achieved at frequencies of 0.117 and 0.161 THz with modulation depths of 13 and 11%, respectively. Because the R-TENG with a multifan blade and circular electrodes can generate 18 peaks of electric output in every rotation, it can successfully provide sufficient frequency alternating-current electric energy to drive the terahertz modulator and achieve a self-powered function. Our findings lay a solid theoretical foundation for further building self-powered THz communication systems and promote the development of a theoretical system for LC-driving spectrum-reconfigurable devices in the THz domain.

Performance evaluation in die-sinking EDM of polygonal micro cavities over EN-24 alloy steel using cylindrical electrode and polygon cycle approach

The integration of advanced Electrical Discharge Machining (EDM) technology, incorporating short and electronically pulsed discharges with precise circular electrode movements, has enabled the production of intricate 3D microstructures and cavities. This paper aims to investigate the machining performance of polygonal cavities—triangular, square, pentagon, and hexagon—fabricated on steel samples using a 400 µm cylindrical copper electrode within the polygon cycle approach of EDM. Experimental investigations were conducted to assess shape error, tool wear rate, recast layer formation, and elemental characterization. Various discharge patterns and side discharges were examined to understand their effects on spark gap uniformity, tool deflection, and discharge stability. The results revealed non-uniform spark gaps, tool deflection, and corner rounding due to varying discharge patterns and side discharges. Tool wear rate was found to be directly related to polygon complexity, with higher-order polygons leading to increased wear due to extended machining durations and heat accumulation. The maximum tool wear of 7.69 × 104 µm3/s occurred in case of hexagonal cavities while in case of triangular cavities, the tool wear rate was minimum having value of 5.77 × 104 µm3/s. Scanning Electron Microscopy (SEM) examinations showed the presence of recast layers and micro-cracks, particularly in cavities with higher shape complexities. Energy Dispersive X-ray Spectroscopy (EDS) analysis identified copper deposition, local material evaporation, and foreign element accumulation on the cavity surfaces. This study provides insights into the machining performance of polygonal cavities in EDM processes. The findings underscore the influence of discharge patterns, polygon complexity, and material interactions on tool wear, surface quality, and microstructure integrity. Understanding these factors can inform optimization strategies for EDM processes, leading to enhanced precision and efficiency in microstructure fabrication.

Controllable concentric electric field line distribution for simultaneous separation of DNA

An approach for the controllable separation and concentration of nucleic acid using a circular nonuniform electric field was proposed and developed. Using six different lengths of DNA molecules as standard samples, the distribution of the gradient electric field was increased from the outer circular electrode to the inner rod-shaped electrode, contributing to the migration of DNA molecules at a velocity gradient towards the region with the strongest inner electric field. The DNA molecules were arranged in a distribution of concentric circles that aligned with the distribution of concentric equipotential lines. The concentration of DNA multiplied with the alternation of radius. As a result, this platform allowed simultaneous DNA separation, achieving a resolution range of 1.17–3.03 through an extended electrophoresis time, resulting in enhanced concentration factors of 1.08–6.27. Moreover, the manipulation of the relative height of the inner and outer electrodes enabled precise control over the distribution and the deflection degree of electric field lines, leading to accurate control over DNA deflection.

Enhanced Sensitivity of Electrocorticography During Awake Craniotomy Using a Novel Circular Grid Electrode (S29.008)

Enhanced Sensitivity of Electrocorticography During Awake Craniotomy Using a Novel Circular Grid Electrode (S29.008)

Electrostatic conductive disc singularity resolved

The conventional electrostatic solutions for two-dimensional (2D) electrodes possess edge singularities for the surface charge density σ and the normal component of the electric field En. These singularities are generally non-physical because they admit infinite gradients of the concentration of free charge carriers. In particular, they are unacceptable in the studies of the local field sensitive effects, such as the electric breakdown and the ferroelectric domain reversal. We claim that account for diffusion of free charge carriers leads to the disappearance of the edge singularities. This generalization occurs consistently within the same basic concept of conduction. Specifically, we consider the case of U-biased circular disc electrode of radius a. Account for diffusion leads here to a strongly nonlinear integral 2D equation for the electrostatic potential φ(r). Numerical solution of this equation shows that the law σ(a)∝U2/a takes place. Outside a close vicinity of the disc edge, we stay close to the conventional electrostatic solution for φ and σ.

Optimization of dry laser-induced graphene (LIG) electrodes for electrocardiography (ECG) signals monitoring

This work presents the optimization of the fabrication procedure for laser-induced graphene (LIG) electrodes intended for biopotentials acquisition. The results presented in this study demonstrate a significant improvement with respect to the performance obtained for other LIG-based electrodes previously reported in the literature. In particular, we propose the use of a galvanometric laser instead of a CNC laser to improve the engraving resolution and the LIG synthesis process, thus enhancing the surface area of the interface skin–electrode. For that, we have studied the resistance of the resulting LIG patterns as a function of the laser parameters (engraving power and scan speed) seeking their optimization. After tunning the laser fabrication process, we have fabricated and characterized electrocardiogram (ECG) electrodes with different surface areas using a commercial silver-based electrode as a reference. Thus, circular electrodes with a diameter of 15 mm, 10 mm and 6.5 mm were used to acquire the ECG on different volunteers using a commercial equipment. The signals acquired were processed afterwards with cutting edge processing techniques to perform a statistical analysis in terms of sensitivity, specificity, positive prediction and accuracy for the detection of QRS complexes. The results demonstrate that the proposed electrodes improve the signal acquisition with respect to the previously reported LIG-based electrodes in terms of noise and do present comparable or even better results than commercial electrodes (even with a smaller surface area) with the additional advantage of not requiring the use of an electrolyte gel.

Three-dimensional carbon interdigitated ring array nanofibers for electrochemical detection of dopamine neurotransmitter

Dopamine (DA) neurotransmitter is a prominent component of the central nervous system and its deficiency contributes to several diseases, such as Parkinson’s disease and schizophrenia, which significantly influence the quality of life of affected individuals. This paper introduces a circular interdigitated ring electrode, the three-dimensional carbon interdigitated ring array nanofibers (3D C-IDRA NFs), for the detection of DA using amperometric detection. The study utilized cyclic voltammetry and chronoamperometry to investigate DA. The integration of carbon nanofibers (CNFs) with 3D C-IDRA demonstrated enhanced surface area, increased current peak, and superior performance compared to the standalone 3D C-IDRA electrode, as evidenced by a redox amplification factor of 2.94 and a collection efficiency of 81.1%. The results highlight that integrating CNFs with 3D C-IDRA improves the electrochemical performance in detecting DA neurotransmitter. Thus, this discovery elucidates the advantageous potential of the 3D C-IDRA NF electrode in a wide range of applications.

Insights and Applications: Evaluating Edge Effects in Planar Capacitors with Advanced Modeling

An analysis of edge effects in planar capacitors with parallel electrodes is presented in this article. Many electronic applications utilize capacitors, and understanding the phenomena around their edges is crucial to their design and optimization. Our research explores in detail the distribution of electric fields and electric potential near electrodes using models and methods based on Maxwell's principles and Gauss's theorem. Divergent electric fields can create edge effects, which affect capacitor performance by creating edge effects. A circular electrode shape is one of the strategies we present to mitigate these effects. The implications of these findings in the field of electronics and related technologies are discussed in the final section.

Abstract B001: Impedance based biomarker for “smart ROSE” pancreatic cancer detection: Initial results from an ongoing clinical trial with nsCanary

Abstract Pancreatic cancer (PC) accounts for half a million new cases and 4.7% of cancer-related deaths globally in 2020. Endoscopic ultrasound (EUS) guided fine needle biopsies (FNB) are the current standard for confirming suspicious lesions, although their diagnostic accuracy remains below 70% with a non-diagnostic rate of the first procedure as high as 40%. Rapid on-site evaluation (ROSE) was introduced to improve diagnostic accuracy via on-site pathology assessment. However, ROSE availability is often limited due to resource constraints. NovaScan has developed the nsCanary, a ”smart ROSE” device, which uses a bioimpedance spectroscopy biomarker based on the Cole Relaxation Frequency (CRF) to detect cancer in biopsy samples in real-time and on-site. The aim of this study is to present initial results from a clinical trial that validates the nsCanary’s ability to detect PC in biopsy samples. Data were collected with the nsCanary device in an IRB approved double-blind study including a cohort of 44 patients (20 males, 24 females; average age of 63 years; 66% White, 22% African American, 12% Hispanic) undergoing EUS procedures with FNB sampling for suspected PC at the Texas International Endoscopy Center in Houston, TX. The nsCanary is a small desktop instrument that performs spectral bioimpedance analysis to extract the CRF based biomarker in less than 30 seconds without altering the biopsied tissue. A touch panel user interface allows for the user to input information and start the measurement. Obtained biopsy samples were flushed in a disposable strainer in order to drain any excess fluid. A circular disposable electrode, consisting of an interdigitated array with alternating polarities was placed in contact with the sample to perform measurements of complex bioimpedance in the 1 kHz - 10 MHz frequency range. The design of the electrode allows it to sense the signal from samples as small as FNB cores. Samples with CRF value below 1 MHz for every scan were considered noncancerous. Samples with at least one CRF value above 1MHz or absence of CRF reading (i.e., CRF out of range) were considered cancerous. PC assessment provided by nsCanary was validated against histopathology outcomes for each biopsy sample. Pathology results indicated that out of the cancerous lesions observed, there were 7 cases of pancreatic adenocarcinoma, 2 cases of invasive adenocarcinoma, 1 case of ductal adenocarcinoma, and 1 case of metastatic renal cell carcinoma. Findings showed a sensitivity of 81.8%, specificity of 84.8%, PPV of 64.3% and NPV of 93.3% for a total of n=44 patients. The device is low cost, portable, and can be used in the surgical suite without interfering with the standard workflow or affecting the sample for following pathological assessment. The implementation of the nsCanary device into the clinic will adjunctively support the decision-making process by providing immediate feedback on cancer detection and sample adequacy. This will enable endoscopists to diagnose PC on the first biopsy procedure, ultimately facilitating prompt treatment of patients. Citation Format: Federica Dibennardo, Martina Guidetti, Onur Fidaner, Daniel S. Gehrke, Donato Ceres, Margaret C. John, Constantine H. Bovalis, Isaac Raijman, Les Bogdanowicz. Impedance based biomarker for “smart ROSE” pancreatic cancer detection: Initial results from an ongoing clinical trial with nsCanary [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B001.

Design and analysis of biconvex liquid lens with circular hole plate electrode structure

In this paper, based on the research of zoom liquid lens with parallel plate electrode and the principle of dielectrophoresis, a model of the biconvex liquid lens with circular hole plate electrode structure is proposed, which is a novel three-layer liquid lens structure. The dielectrophoretic effect refers to the phenomenon that free dielectric molecules will be polarized and moved by the force in a non-uniform electric field, thus deforming the dielectric liquid. In the dielectrophoretic liquid lens, only two insulating liquid materials with large refractive index difference and dielectric constant difference need to be selected, which can increase the selection range of liquid materials. The liquid lens structure mainly consists of a piece of double-sided conductive flat plate ITO glass with a circular hole and two pieces of single-sided conductive flat plate ITO glass, which respectively form two sets of flat electrode structures to control the upper interface and lower interface of the liquid droplet. In this structure, the influences of the intermediate glass plate on the focus and imaging are reduced by using the flat plate electrode with circular hole. The theoretical analysis of the structure is carried out with simulation software. Firstly, the models of the biconvex liquid lens with circular hole plate electrode under different voltages are built with Comsol software, the data of upper interface and lower interface of the liquid droplet are exported. Then by using Matlab, the surface shapes of the upper interface and lower interface of the droplet are fitted and the corresponding aspheric coefficients are obtained. Finally, the optical models are built with Zemax software, the imaging optical paths and the variation range of focal length under different voltages are analyzed. On the basis of the simulation, the corresponding device is made, and the specific experimental analysis is carried out. The surface patterns of the upper interface and lower interfaces of the droplet of the biconvex liquid lens under different voltages are recorded, the focal length and imaging resolution of the liquid lens are measured. When the operating voltage is in a range of 0–260 V, the focal length varies from 23.8–17.5 mm, which is basically consistent with the simulation results (22.6–15.9 mm). The feasibility of the structure of the biconvex liquid lens with circular hole plate electrode structure is verified experimentally. The imaging resolution can reach 45.255 lp/mm. The results show that this proposed novel three-layer liquid structure of the biconvex liquid lens has the characteristics of simple structure, easy-to-realize and good imaging quality. Therefore, the research of this biconvex liquid lens can provide a new idea for expanding the high-resolution imaging research of liquid lenses and their applications.

A Clinically Feasible Electrode Array for 3D Intraoperative Electrical Impedance Tomography-Based Surgical Margin Assessment in Robot-Assisted Radical Prostatectomy.

A novel small form factor circular electrode array was designed specifically for electrical impedance tomography (EIT) based assessment of surgical margins during robot assisted radical prostatectomy (RARP). The electrode array consists of 33 gold-plated electrodes arranged within a 9.5mm diameter circular footprint on the end of a surgical probe that can be introduced through a standard 12mm laparoscopic port used during RARP. The electrode array contains 8 larger, low-contact impedance outer electrodes dedicated for current drive and an internal grid of 25 smaller electrodes for simultaneous voltage measurement. Separating electrode geometry by function is designed to improve current delivery, speed, and resolution while reducing hardware requirements. Simulations demonstrated that 1mm diameter hemispherical prostate cancer inclusions could be localized within regions of adipose and benign prostate tissue; 1.5mm diameter inclusions were required for localization within muscle tissue. A 2.38mm diameter aluminum rod in 0.2 S/m saline could be localized throughout the imaging domain with a position error of less than 2.5mm for depths from the electrode array surface of up to 1.7mm. Ex vivo tissue experiments with a bovine model demonstrate visual congruence of muscle and adipose tissue locations between the sample and reconstructed images. Simulation and experimental results indicate good detection and location of inclusions. These results suggest the proposed electrode array design can provide sufficient accuracy in the detection and localization of prostate cancer against clinically relevant background tissues for use during RARP.

(Invited) Development of Sustainable Electrocatalysts for Anion Exchange Membrane Fuel Cells and Electrolyzers

The electrocatalytic hydrogen oxidation (HOR) and evolution (HER) reactions under alkaline conditions are kinetically slow processes even when Pt group metals are employed. This presentation discusses our strategies to improve the activity of non platinum catalysts. For example, to improve the alkaline HOR activity of transition metal nanoparticles we look at engineering strong interactions with metal oxides incorporated with carbon-based catalyst supports.(1,2) Another strategy involves utilizing novel carbon materials such as onion like carbon (OLC). We have shown that the combination of CeO2 and OLC in Pd–CeO2/OLC induces surface defects and modifies the electronic structure of the Pd-OLC interface, significantly improving electrical conductivity due to enhanced charge redistribution. Such results were corroborated by density functional theory (DFT) calculations.(3) Using this strategy, peak power densities of up to 2 W cm-2 have been achieved when Pd-CeO2 is incorporated in AEMFCs.(4) Regarding the alkaline HER, mixed phase Ni-Mo and MoO3-x materials are known to have enhanced alkaline hydrogen evolution reaction (HER) activity. Here we describe the optimization of the preparation of an active HER catalyst composed of MoO2 surface nanorod arrays on nickel foam (see Figure). Large circular cathode electrodes (Area 80 cm2) were prepared and tested in a three cell stack AEM electrolyser.(5) M. V. Pagliaro, C. L. Wen, B. Sa, B. Y. Liu, M. Bellini, F. Bartoli, S. Sahoo, R. K. Singh, S. P. Alpay, H. A. Miller and D. R. Dekel, ACS Catal., 10894 (2022).M. V. Pagliaro, M. Bellini, F. Bartoli, J. Filippi, A. Marchionni, C. Castello, W. Oberhauser, L. Poggini, B. Cortigiani, L. Capozzoli, A. Lavacchi, H. A. Miller and F. Vizza, Inorg. Chim. Acta, 543 (2022).J. Ogada, A. K. Ipadeola, P. V. Mwonga, A. B. Haruna, F. Nichols, S. W. Chen, H. A. Miller, M. V. Pagliaro, F. Vizza, J. R. Varcoe, D. M. Meira, D. M. Wamwangi and K. I. Ozoemena, ACS Catal., 12, 10938 (2022).H. A. Miller, M. Bellini, D. R. Dekel, and F. Vizza, Electrochemistry Communications, 135, 107219 (2022).F. Bartoli, L. Capozzoli, T. Peruzzolo, M. Marelli, C. Evangelisti, k. Bouzek, J. Hnat, G. Serrano, L. Poggini, K. Stojanovski, V. Briega-Martos, S. Cherevko, H. A. Miller and F. Vizza, J. Mater. Chem. A, 11, 5789 (2023). Figure 1