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A 30-μW wireless fast-scan cyclic voltammetry monitoring integrated circuit for ultra-wideband (UWB) transmission of dopamine release events in freely-behaving small animals is presented. On-chip integration of analog background subtraction and UWB telemetry yields a 32-fold increase in resolution versus standard Nyquist-rate conversion alone, near a four-fold decrease in the volume of uplink data versus single-bit, third-order, delta-sigma modulation, and more than a 20-fold reduction in transmit power versus narrowband transmission for low data rates. The 1.5-mm2 chip, which was fabricated in 65-nm CMOS technology, consists of a low-noise potentiostat frontend, a two-step analog-to-digital converter (ADC), and an impulse-radio UWB transmitter (TX). The duty-cycled frontend and ADC/UWB-TX blocks draw 4 μA and 15 μA from 3-V and 1.2-V supplies, respectively. The chip achieves an input-referred current noise of 92 pArms and an input current range of ±430 nA at a conversion rate of 10 kHz. The packaged device operates from a 3-V coin-cell battery, measures 4.7 × 1.9 cm2, weighs 4.3 g (including the battery and antenna), and can be carried by small animals. The system was validated by wirelessly recording flow-injection of dopamine with concentrations in the range of 250 nM to 1 μM with a carbon-fiber microelectrode (CFM) using 300-V/s FSCV.

A potentiostat circuit for the application of bipolar electrode voltages and detection of bidirectional currents using a microelectrode array is presented. The potentiostat operates as a regulated-cascode amplifier for positive input currents, and as an active-input regulated-cascode mirror for negative input currents. This topology enables constant-potential amperometry and fast-scan cyclic voltammetry (FSCV) at microelectrode arrays for parallel recording of quantal release events, electrode impedance characterization, and high-throughput drug screening. A 64-channel FSCV detector array, fabricated in a 0.5-μm, 5-V CMOS process, is also demonstrated. Each detector occupies an area of 45 μm × 30 μm and consists of only 14 transistors and a 50-fF integrating capacitor. The system was validated using prerecorded input stimuli from actual FSCV measurements at a carbon-fiber microelectrode.

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As Moore’s law and Dennard scaling come to an end, new devices and computing architectures are being explored. The development of computing hardware designed to address the rapidly growing need for computational power to accelerate artificial intelligence applications has prompted investigations into both. While silicon photonics is typically viewed as a communications platform, we discuss its application to artificial intelligence and some outstanding challenges to be addressed.

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Impulse Radios within communication networks using Pulse Coupled Oscillator (PCO) global synchronization can be efficiently duty cycled for significant power savings. In this paper we utilize the emergent dynamical behavior in the PCO network to enable a simple event communication scheme particular to this type of network. In this scheme, each coupled radio node accesses the channel by simply changing its pulse repetition frequency in response to an event sensed by its sensor. This forces the network to a new, higher operating frequency, which can be locally measured at every node in the network to communicate occurrence of an event in the network. In this paper we show how this synchronization occurs and how it is ideally suited for low power operation. The proposed event propagation scheme enables a node to broadcast information about an event to an entire network in a simple fashion without the need of any datapacket formation or complex MAC/Routing protocols. We show that resynchronization and recovery of the network happens almost immediately. The latency involved corresponds to the distance-delay (due to finite speed of light) plus a very small circuit delay of (4-5ns) per hop related to detection of impulses.

Complementary metal–oxide–semiconductor (CMOS) microelectrode arrays integrate amplifier arrays with on-chip electrodes, offering high-throughput platforms for electrochemical sensing with high spatial and temporal resolution. Such devices have been developed for highly parallel constant voltage amperometric detection of transmitter release from multiple cells with single-vesicle resolution. Cyclic voltammetry (CV) is an electrochemical method that applies voltage waveforms, which provides additional information about electrode properties and about the nature of analytes. A 16-channel, 64-electrode-per-channel CMOS integrated circuit (IC) fabricated in a 0.5 μm CMOS process for CV is demonstrated. Each detector consists of only 11 transistors and an integration capacitor with a unit dimension of 0.0015 mm 2 . The device was postfabricated using Pt as the working electrode material with a shifted electrode design, which makes it possible to redefine the size and the location of working electrodes. The system incorporating cell-sized (8 μm radius) microelectrodes was validated with dopamine injection tests and CV measurements of potassium ferricyanide at a 1 V/s scanning rate. The cyclic voltammograms were in excellent agreement with theoretical predictions. The technology enables rigorous characterization of electrode performance for the application of CMOS microelectrode arrays in low-noise amperometric measurements of quantal transmitter release as well as other biosensing applications.