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A study conducted by researchers at Delft University of Technology in the Netherlands has provided new insights into obesity, fitness, and wellness. The study focuses on the development of a practical guide to build a Raspberry Pi Pico based potentiostat for educational electrochemistry and electronic instrumentation. The circuit allows for various types of voltammetry, such as cyclic and square wave voltammetry. The research involved over 80 nanobiology bachelor students who successfully built their own potentiostat and conducted electrochemical experiments using pharmaceutical tablets. The study concludes that the students gained valuable knowledge and skills in electronic building blocks and system architecture within electrochemical instrumentation. [Extracted from the article]

Electrochemical experiments like chronoamperometry or cyclic voltammetry (CV) are essential in the research for novel bioelectrochemical systems. These experiments, executed by a potentiostat, are time-consuming which hinders research progression. To speed up those experiments, this work presents a potentiostat with 128 individual parallel stimulation and sensing channels. A channel architecture exploiting time division multiplexing is developed to minimize the hardware cost and area. Potential control is done in the digital domain using 128 individual Linear Quadratic Integral (LQI) controllers. The 128-channel potentiostat is implemented with Printed Circuit Board (PCB) technology and has $16 {\times }$ more channels than the state of the art low-cost potentiostats with a $4 {\times }$ lower cost-per-channel (5 $) and a $4 {\times }$ lower area-per-channel (${93}\,mm^{2}$). Using parallelism, chronoamperometry experiments can be done ${128\times }$ faster, while a conventional ${1}\, mV\,s^{-1}$ -CV can be done $72\,\, {\times }$ faster by sampling instead of voltage sweeping. [ABSTRACT FROM AUTHOR]

There is a requirement for an electrochemical sensor technology capable of making multivariate measurements in environmental, healthcare, and manufacturing applications. Here, we present a new device that is highly parallelized with an excellent bandwidth. For the first time, electrochemical cross-talk for a chip-based sensor is defined and characterized. The new CMOS electrochemical sensor chip is capable of simultaneously taking multiple, independent electroanalytical measurements. The chip is structured as an electrochemical cell microarray, comprised of a microelectrode array connected to embedded self-contained potentiostats. Speed and sensitivity are essential in dynamic variable electrochemical systems. Owing to the parallel function of the system, rapid data collection is possible while maintaining an appropriately low-scan rate. By performing multiple, simultaneous cyclic voltammetry scans in each of the electrochemical cells on the chip surface, we are able to show (with a cell-to-cell pitch of 456 $\mu \text{m}$ ) that the signal cross-talk is only 12% between nearest neighbors in a ferrocene rich solution. The system opens up the possibility to use multiple independently controlled electrochemical sensors on a single chip for applications in DNA sensing, medical diagnostics, environmental sensing, the food industry, neuronal sensing, and drug discovery. [ABSTRACT FROM AUTHOR]

This paper presents a low-power all-MOS delta-sigma ADC specifically optimized for the potentiostatic biasing and amperometric read-out of electrochemical sensors. The proposed architecture reuses the dynamic properties of the sensor itself to implement a continuous-time mixed electrochemical delta-sigma modulator with minimalist analog circuits fully integrable in purely digital CMOS technologies. A 25-µW smart electrochemical sensor demonstrator integrated in low-cost 1M CMOS technology with Au post-processing is presented. Experimental results show electrical dynamic range values exceeding 10-bit, while electrochemical figures exhibit linearity levels close to R² = 0.999 combined with RSD < 15% in terms of reproducibility. A comparative test with commercial potentiostat equipment is also included to qualify the performance of the proposed ADC. [ABSTRACT FROM PUBLISHER]

The critical pitting temperature (CPT) of 2101 lean duplex stainless steel (DSS) in 1 mol/L NaCl was investigated. Potentiostatic electrochemical noise (EN) technique coupled with scanning electron microscopy (SEM) was used to study the corrosion process of 2101 DSS at different temperatures (15, 25, 28, and 35 °C) from below CPT to above CPT. The EN data were analyzed by wavelet technique based on orthogonal db4 wavelet. The results showed that, the patterns of current noises were different at different temperatures. The characteristics of energy distribution plot (EDP) obtained from wavelet analysis technique can be used as “fingerprints” of EN signal and can be used to interpret the corrosion process. With increasing solution temperature, the maximum relative energy defined in EDP changed from the region of crystal series coefficients with smaller scales through middle scales to larger scales, which indicated the process of initiation, propagation and growth into stable pitting of metastable pitting. The results were well confirmed by the corresponding morphologies. [Copyright &y& Elsevier]

We present a new circuit topology for potentiostats that interface with three-electrode amperometric electrochemical sensors. In this new topology, a current-copying circuit, e.g., a current mirror, is placed in the sensor current path to generate a mirrored image of the sensor current. The mirrored image is then measured and processed instead of the sensor current itself. The new potentiostat topology consumes very low power, occupies a very small die area, and has potentially very low noise. These characteristics make the new topology very suitable for portable or bioimplantable applications. In order to demonstrate the feasibility of the new topology, we present the results of a potentiostat circuit implemented in a 0.18-μm CMOS process. The circuit converts the sensor current to a frequency-modulated pulse waveform, for which the time difference between two consecutive pulses is inversely proportional to the sensor current. The potentiostat measures the sensor current from 1 nA to 1 μA with better than 0.1% of accuracy. It consumes only 70 μW of power from a 1.8-V supply voltage and occupies an area of 0.02 mm2. [ABSTRACT FROM AUTHOR]

High-throughput electrode arrays are required for advancing devices for testing the effect of drugs on cellular function. In this paper, we present design criteria for a potentiostat circuit that is capable of measuring transient amperometric oxidation currents at the surface of an electrode with submillisecond time resolution and picoampere current resolution. The potentio- stat is a regulated cascode stage in which a high-gain amplifier maintains the electrode voltage through a negative feedback loop. The potentiostat uses a new shared amplifier structure in which all of the amplifiers in a given row of detectors share a common half circuit permitting us to use fewer transistors per detector. We also present measurements from a test chip that was fabricated in a 0.5-μm, 5-V CMOS process through MOSIS. Each detector occupied a layout area of 35 μm x 15 μm and contained eight transistors and a 50-fF integrating capacitor. The rms current noise at 2-kHz bandwidth is ≈110 fA. The maximum charge storage capacity at 2 kHz is 1.26 x 106 electrons. [ABSTRACT FROM AUTHOR]

We present the architecture and VLSI circuit implementation of a BiCMOS potentiostat bank for monitoring neurotransmitter concentration on a screen-printed carbon electrode array. The potentiostat performs simultaneous acquisition of bidirectional reduction-oxidation currents proportional to neurotransmitter concentration on 16 independent channels at controlled redox potentials. Programmable current gain control yields over 100-dB cross-scale dynamic range with 46-pA input-referred rms noise over 12-kHz bandwidth. The cutoff frequency of a second-order log-domain anti-aliasing filter ranges from 50 Hz to 400 kHz. Track-and-hold current integration is triggered at the sampling rate between dc and 200 kHz. A 2.25-mm × 2.25-mm prototype was fabricated in a 1.2-μm VLSI technology and dissipates 12.5 mW. Chronoamperometry dopamine concentration measurements results are given. Other types of neurotransmitters can be selected by adjusting the redox potential on the electrodes and the surface properties of the sensor coating. [ABSTRACT FROM AUTHOR]

We designed and tested an integrated patch-clamp amplifier capable of recording from pico to tens of microamperes of current. The high-dynamic range of seven decades and the picoampere sensitivity of the instrument was targeted to whole-cell patch-clamp recordings. The prototype was fabricated on a 0.5-μm silicon-on-sapphire process. The device employs an integrating headstage with a pulse frequency modulated output, ranging from 3 Hz to 10 MHz. A digital interface produces a 16-bit output conversion of the input currents. We report on electronic characterization of the fabricated device, dynamic performance, and examples of measurements on biological cells for patch-clamp applications. The device will be used in an advanced planar high-throughput patch-clamp screening system for testing medicines. [ABSTRACT FROM AUTHOR]

Rapid and accurate detection of pathogens using conductometric biosensors requires potentiostats that can measure small variations in conductance. In this paper, we present an architecture and implementation of a multichannel potentiostat array based on a novel semi-synchronous sigma-delta (ΣΔ) analog-to-digital conversion algorithm. The algorithm combines continuous time ΣΔ with time-encoding machines, and enables measurement of currents down to femtoampere range. A 3-mm × 3-mm chip implementing a 42-channel potentiostat array has been prototyped in a 0.5-μm CMOS technology. Measured results demonstrate that the prototype can achieve 10 bits of resolution, with a sensitivity down to 50-fA current. The power consumption of the potentiostat has been measured to be 11 μW per channel for a sampling rate of 250 kHz. Experiments with a conductometric biosensor specific to Bacillus Cereus bacterium, demonstrate the ability of the potentiostat in identifying different concentration levels of the pathogen in a biological sample. [ABSTRACT FROM AUTHOR]

The article offers insights on the advantages of modifying a guitar with push/pull potentiometers. Aside from upgrading a guitar's stock pots, push/pull potentiometers offer discrete circuit switching options such as coil splitting, circuit bypass and phase-reverse options. Tips for properly using the potentiometers are also provided.

The article presents questions and answers related to cathodic protection including how to install horizontal anodes in a horizontal groundbed design, how to prepare a deep anode groundbed, and how to build a potentiostat.

The article previews the Reference Line of Potentiostats from Gamry Instruments.

Evaluates several products for corrosion prevention and control available in the U.S. market in February 2005. FastLine Portable Lining Unit from DUOLINE Technologies; GILL AC BI-STAT bi-potentiostat system from ACM Instruments; PosiTest Pull-Off Adhesion Tester from DeFelsko Corp.

The article evaluates the PMC-2000 Channel from Advanced Measurement Technology that has been added to its Parstat MC Potentiostat to enhance their capabilities.

The article evaluates the PARSTAT MC multi-channel potentiostat/galvanostat for electrochemistry research and testing from Ametek Inc.

The article offers brief information on the 910 PSTAT mini potentiostat for training and simple applications in research and development (R&D) from Metrohm AG.

The article features the 910 PSTAT mini, a personal computer-controlled, small and compact potentiostat from Metrohm suited for simple applications in research and development (R&D).

The article evaluates the Multi-Channel Potentiostat for corrosion testing from Scribner Associates Inc.

Evaluates the use of linear potentiometers in audio applications. Ways in making a linear pot function like an audio pot; Comparison of the output of linear pots and audio pots.

Discusses the design of a positive-to-negative voltage regulator. Reliance on a charge pump and capacitor; Ability to invert and step up or step down the input voltage.