Nanocrystals (NCs) discussed in this Review are tiny crystals of metals, semiconductors, and magnetic material consisting of hundreds to a few thousand atoms each. Their size ranges from 2-3 to about 20 nm. What is special about this size regime that placed NCs among the hottest research topics of the last decades? The quantum mechanical coupling * To whom correspondence should be addressed. E-mail: dvtalapin@uchicago.edu. † The University of Chicago. ‡ Argonne National Lab. Chem. Rev. 2010, 110, 389–458 389

/pdf/prospects-of-colloidal-nanocrystals-for-electronic-and-3dxpyhl3r7.pdf

Prospects of Colloidal Nanocrystals for Electronic and Optoelectronic Applications

The computational brain: Patricia S. Churchland and Terrence J. Sejnowski (MIT Press, Cambridge, MA, 1992); xi, 544 pages, $39.95

The evolution of ubiquitous sensing technologies has led to intelligent environments that can monitor and react to our daily activities, such as adapting our heating and cooling systems, responding to our gestures, and monitoring our elderly. In this paper, we ask whether it is possible for smart environments to monitor our vital signs remotely, without instrumenting our bodies. We introduce Vital-Radio, a wireless sensing technology that monitors breathing and heart rate without body contact. Vital-Radio exploits the fact that wireless signals are affected by motion in the environment, including chest movements due to inhaling and exhaling and skin vibrations due to heartbeats. We describe the operation of Vital-Radio and demonstrate through a user study that it can track users' breathing and heart rates with a median accuracy of 99%, even when users are 8~meters away from the device, or in a different room. Furthermore, it can monitor the vital signs of multiple people simultaneously. We envision that Vital-Radio can enable smart homes that monitor people's vital signs without body instrumentation, and actively contribute to their inhabitants' well-being.

/pdf/smart-homes-that-monitor-breathing-and-heart-rate-425fzf6qc1.pdf

Smart Homes that Monitor Breathing and Heart Rate

This paper discusses connectivity between neuromorphic chips, which use the timing of fixed-height fixed-width pulses to encode information. Address-events (log/sub 2/(N)-bit packets that uniquely identify one of N neurons) are used to transmit these pulses in real time on a random-access time-multiplexed communication channel. Activity is assumed to consist of neuronal ensembles-spikes clustered in space and in time. This paper quantifies tradeoffs faced in allocating bandwidth, granting access, and queuing, as well as throughput requirements, and concludes that an arbitered channel design is the best choice. The arbitered channel is implemented with a formal design methodology for asynchronous digital VLSI CMOS systems, after introducing the reader to this top-down synthesis technique. Following the evolution of three generations of designs, it is shown how the overhead of arbitrating, and encoding and decoding, can be reduced in area (from N to /spl radic/N) by organizing neurons into rows and columns, and reduced in time (from log/sub 2/(N) to 2) by exploiting locality in the arbiter tree and in the row-column architecture, and clustered activity. Throughput is boosted by pipelining and by reading spikes in parallel. Simple techniques that reduce crosstalk in these mixed analog-digital systems are described.

/pdf/point-to-point-connectivity-between-neuromorphic-chips-using-2x6lccyaeo.pdf

Point-to-point connectivity between neuromorphic chips using address events

https://www.cse.iitk.ac.in/users/isaha/Publications/Journals/NC10.pdf/

Artificial neural networks in hardware: A survey of two decades of progress

This paper describes a new first- and second-order delta-sigma modulator concept where the first integrator is extracted and implemented by a frequency modulator with the modulating signal as the input. The result is a simple delta-sigma modulator with no need for digital-to-analog converters, allowing straightforward multibit quantization. Without the frequency modulator, the circuit becomes a frequency-to-digital converter with delta-sigma noise shaping. An experimental first- and second-order modulator has been implemented in a 1.2-/spl mu/m standard digital CMOS process and the results confirm the theory. For the first-order modulator an input signal amplitude of 150 mV resulted in a signal-to-quantization noise ratio (SQNR) of /spl ap/115 dB at 2 MHz sampling frequency and signal bandwidth of 500 Hz.

Delta-sigma modulators using frequency-modulated intermediate values

Over the past decade, ion-sensitive field-effect transistors (ISFETs) have played a major role in enabling the fabrication of fully integrated CMOS-based chemical sensing systems. This has allowed several new application areas, with the most promising being the fields of ion imaging and full genome sequencing. This paper reviews the new trends in front-end topologies toward the design of ISFET sensing arrays in CMOS for these new applications. More than a decade after the review of the ISFET by Bergveld which summarized the state of the art in terms of device and early readout circuity, we describe the evolution in terms of device macromodel and identify the main sensor challenges for current designers. We analyze the techniques that have been reported for both ISFET instrumentation and compensation, and conclude that topologies are focusing on device adaptation for offset and drift cancellation, as opposed to system compensation which are often not as robust. Guidelines are provided to build a tailored CMOS ISFET array, emphasizing that the needs in terms of applications are the keys to selecting the right pixel architecture. Over the next few years, the race for the largest and densest array is likely to be put on hold to allow the research to focus on new pixel topologies, ultimately leading to the development of reliable and scalable arrays. A wide range of new applications are expected to motivate this paper for at least another decade.

ISFETs in CMOS and Emergent Trends in Instrumentation: A Review

Overview of floating-gate devices, circuits, and systems

A new approach to the design of a low-power cascadable analogue filter for applications such as silicon cochlea implants is described. One section of a possible silicon cochlea based on a second-order continuous-time filter employing MOS technology operating in weak inversion is presented. The idea is based on the recently proposed log-domain filter approach used previously in bipolar technology.

Micropower log-domain filter for electronic cochlea

This paper describes a novel technique for implementing ultra low-voltage/low-power digital circuits The effective threshold voltage seen from a control gate is adjusted during a UV-light-activated tuning procedure The optimal effective threshold voltage matching the supply voltage and speed may be programmed by UV light through an activated conductance between the power rails and the floating gates Measured results are provided for gates operating down to 04-V power supply, using a standard double-poly CMOS process

Tor Sverre Lande

Papers

Delta-sigma modulators using frequency-modulated intermediate values

ISFETs in CMOS and Emergent Trends in Instrumentation: A Review

Overview of floating-gate devices, circuits, and systems

Micropower log-domain filter for electronic cochlea

Ultra low-voltage/low-power digital floating-gate circuits