26 research outputs found
Wide Dynamic Range CMOS Potentiostat for Amperometric Chemical Sensor
Presented is a single-ended potentiostat topology with a new interface connection between sensor electrodes and potentiostat circuit to avoid deviation of cell voltage and linearly convert the cell current into voltage signal. Additionally, due to the increased harmonic distortion quantity when detecting low-level sensor current, the performance of potentiostat linearity which causes the detectable current and dynamic range to be limited is relatively decreased. Thus, to alleviate these irregularities, a fully-differential potentiostat is designed with a wide output voltage swing compared to single-ended potentiostat. Two proposed potentiostats were implemented using TSMC 0.18-ÎĽm CMOS process for biomedical application. Measurement results show that the fully differential potentiostat performs relatively better in terms of linearity when measuring current from 500 pA to 10 uA. Besides, the dynamic range value can reach a value of 86 dB
Real-Time Telemetry System for Amperometric and Potentiometric Electrochemical Sensors
A real-time telemetry system, which consists of readout circuits, an analog-to-digital converter (ADC), a microcontroller unit (MCU), a graphical user interface (GUI), and a radio frequency (RF) transceiver, is proposed for amperometric and potentiometric electrochemical sensors. By integrating the proposed system with the electrochemical sensors, analyte detection can be conveniently performed. The data is displayed in real-time on a GUI and optionally uploaded to a database via the Internet, allowing it to be accessed remotely. An MCU was implemented using a field programmable gate array (FPGA) to filter noise, transmit data, and provide control over peripheral devices to reduce power consumption, which in sleep mode is 70 mW lower than in operating mode. The readout circuits, which were implemented in the TSMC 0.18-ÎĽm CMOS process, include a potentiostat and an instrumentation amplifier (IA). The measurement results show that the proposed potentiostat has a detectable current range of 1 nA to 100 ÎĽA, and linearity with an R2 value of 0.99998 in each measured current range. The proposed IA has a common-mode rejection ratio (CMRR) greater than 90 dB. The proposed system was integrated with a potentiometric pH sensor and an amperometric nitrite sensor for in vitro experiments. The proposed system has high linearity (an R2 value greater than 0.99 was obtained in each experiment), a small size of 5.6 cm Ă— 8.7 cm, high portability, and high integration
Bioelectronics for Amperometric Biosensors
The Discrete-to-Integrated Electronics group (D2In), at the University of Barcelona, in
partnership with the Bioelectronics and Nanobioengineering Group (SICBIO), is researching
Smart Self-Powered Bio-Electronic Systems. Our interest is focused on the development of
custom built electronic solutions for bio-electronics applications, from discrete devices to
Application-specific integrated circuit (ASIC) solutions.
The integration of medical and electronic technologies allows the development of biomedical
devices able to diagnose and/or treat pathologies by detecting and/or monitoring pathogens,
multiple ions, PH changes, and so on. Currently this integration enables advances in various
areas such as microelectronics, microfluidics, microsensors and bio-compatible materials
which open the door to developing human body Lab-on-a-Chip implantable devices, Pointof-
Care in vitro devices, etc.
In this chapter the main attention is focused on the design of instrumentation related to
amperometrics biosensor: biopotentiostat amplifiers and lock-in amplifiers. A potentiostat is
a useful tool in many fields of investigation and industry performing electrochemical trials [1],
so the quantity and variety of them is very extensive. Since they can be used in studies and
targets as different as the study of chemical metal conversions [2] or carcinogenic cells
detection, neuronal activity detection or Deoxyribonucleic acid (DNA) recognition, their
characteristics are very varied..
Recent Advances in Neural Recording Microsystems
The accelerating pace of research in neuroscience has created a considerable demand for neural interfacing microsystems capable of monitoring the activity of large groups of neurons. These emerging tools have revealed a tremendous potential for the advancement of knowledge in brain research and for the development of useful clinical applications. They can extract the relevant control signals directly from the brain enabling individuals with severe disabilities to communicate their intentions to other devices, like computers or various prostheses. Such microsystems are self-contained devices composed of a neural probe attached with an integrated circuit for extracting neural signals from multiple channels, and transferring the data outside the body. The greatest challenge facing development of such emerging devices into viable clinical systems involves addressing their small form factor and low-power consumption constraints, while providing superior resolution. In this paper, we survey the recent progress in the design and the implementation of multi-channel neural recording Microsystems, with particular emphasis on the design of recording and telemetry electronics. An overview of the numerous neural signal modalities is given and the existing microsystem topologies are covered. We present energy-efficient sensory circuits to retrieve weak signals from neural probes and we compare them. We cover data management and smart power scheduling approaches, and we review advances in low-power telemetry. Finally, we conclude by summarizing the remaining challenges and by highlighting the emerging trends in the field
Study on Integrated Redox Image Sensor Employing Square Wave Voltammetry
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IEEE Trans Biomed Circuits Syst
Airborne pollutants are a leading cause of illness and mortality globally. Electrochemical gas sensors show great promise for personal air quality monitoring to address this worldwide health crisis. However, implementing miniaturized arrays of such sensors demands high performance instrumentation circuits that simultaneously meet challenging power, area, sensitivity, noise and dynamic range goals. This paper presents a new multi-channel CMOS amperometric ADC featuring pixel-level architecture for gas sensor arrays. The circuit combines digital modulation of input currents and an incremental \uce\ua3\ue2\u2c6\u2020 ADC to achieve wide dynamic range and high sensitivity with very high power efficiency and compact size. Fabricated in 0.5 [Formula: see text] CMOS, the circuit was measured to have 164 dB cross-scale dynamic range, 100 fA sensitivity while consuming only 241 [Formula: see text] and 0.157 [Formula: see text] active area per channel. Electrochemical experiments with liquid and gas targets demonstrate the circuit's real-time response to a wide range of analyte concentrations.R01 ES022302/ES/NIEHS NIH HHS/United StatesR01 OH009644/OH/NIOSH CDC HHS/United States2017-08-01T00:00:00Z27352395PMC505675
Sub-mW Reconfigurable Interface IC for Electrochemical Sensing
The IronIC project has the aim of developing a fully implantable and remotely powered platform for the real- time monitoring of human metabolites. In this paper we present a mixed-signal interface IC for the electrochemical sensing data acquisition chain. The IC controls and reads out up to five biomolecular sensors, by receiving commands from a standard interface to conduct chronoamperometry (CA) and cyclic voltammetry (CV). Different voltage profiles are generated by using a single fully on-chip reconfigurable waveform generator, while the measured data are digitized. The IC is realized in 0.18 μm CMOS technology. Electrical measurements show that the linear readout current range is ±1650 nA with 8-bit resolution. The cyclic voltammetry of potassium ferricyanide and the chronoamperometry of hydrogen peroxide have been successfully performed with the interface. The IC consumes 0.92 mW from 1.8 V supply voltage, making it suitable for remotely powered and implantable applications
Autonomous readout ASIC with 169dB input dynamic range for amperometric measurement
—A readout circuit for the measurement of amperometric sensors is presented. The circuit consists of analog
frontend (AFE) and an automatic gain adjustment circuit to tune
the gain of the AFE according to the input current covering a
wide dynamic range of 169dB and a minimum input referred
noise of 44 fA. The circuit is implemented in 0.35 µm technology,
consumes 5.83 mW from 3.3 V supply voltage and occupies
0.31 mm2
silicon area