Automatic synthesis of analog layout : a survey

A review of recent research in the automatic synthesis of physical geometry for analog integrated circuits is presented. On introduction, an explanation of the difficulties involved in analog layout as opposed to digital layout is covered. Review of the literature then follows. Emphasis is placed on the exposition of general methods for addressing problems specific to analog layout, with the details of specific systems only being given when they surve to illustrate these methods well. The conclusion discusses problems remaining and offers a prediction as to how technology will evolve to solve them. It is argued that although progress has been and will continue to be made in the automation of analog IC layout, due to fundamental differences in the nature of analog IC design as opposed to digital design, it should not be expected that the level of automation of the former will reach that of the latter any time soon

A Construction Kit for Efficient Low Power Neural Network Accelerator Designs

Implementing embedded neural network processing at the edge requires efficient hardware acceleration that couples high computational performance with low power consumption. Driven by the rapid evolution of network architectures and their algorithmic features, accelerator designs are constantly updated and improved. To evaluate and compare hardware design choices, designers can refer to a myriad of accelerator implementations in the literature. Surveys provide an overview of these works but are often limited to system-level and benchmark-specific performance metrics, making it difficult to quantitatively compare the individual effect of each utilized optimization technique. This complicates the evaluation of optimizations for new accelerator designs, slowing-down the research progress. This work provides a survey of neural network accelerator optimization approaches that have been used in recent works and reports their individual effects on edge processing performance. It presents the list of optimizations and their quantitative effects as a construction kit, allowing to assess the design choices for each building block separately. Reported optimizations range from up to 10'000x memory savings to 33x energy reductions, providing chip designers an overview of design choices for implementing efficient low power neural network accelerators

VLSI Design

This book provides some recent advances in design nanometer VLSI chips. The selected topics try to present some open problems and challenges with important topics ranging from design tools, new post-silicon devices, GPU-based parallel computing, emerging 3D integration, and antenna design. The book consists of two parts, with chapters such as: VLSI design for multi-sensor smart systems on a chip, Three-dimensional integrated circuits design for thousand-core processors, Parallel symbolic analysis of large analog circuits on GPU platforms, Algorithms for CAD tools VLSI design, A multilevel memetic algorithm for large SAT-encoded problems, etc

NASA Tech Briefs, August 1993

Topics include: Computer Graphics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences; Books and Reports

Soft Sensors in digital healthcare monitoring

Stretchable sensors are a class of materials with applications across research fields from healthcare to structural engineering. Despite the extensive research aiming to improve the performance of individual materials or components, stretchable sensor devices are difficult to implement because conventional electronic components, mainly used for processing, which are rigid, have to make contact with soft components reliable enough to withstand real-world usage. This thesis introduces a method for creating electrical contacts that can be robustly attached onto soft, stretchable conductive polymer composites on one side and soldered to metal wires on the other side. Mechanically robust electrical contacts were developed to interface (soft) silicone-based strain sensors with conventional (hard) solid-state electronics using a nanoporous silicon-copper contact. Contacts are mounted on custom-made and commercial soft strain sensitive silicone sensors. The contacts are shown to be reliable under large deformations, then compared with a commonly used alternative under real-world strain conditions. The layered structure of the device creates a complex electronic component deriving from the silicon-copper Schottky junction. This thesis tests the versatility of the technology through a series of real-world applications. The silicon-copper contacts were used to produce a series of proof-of-concept devices, including a wearable respiration monitor, leg band for exercise monitoring, and squeezable ball to monitor rehabilitation of patients with hand injuries or neurological disorders. The sensor is shown to operate and detect multiple modes of motion regardless of placement on the body. Next, a proof-of-concept device was employed to measure hand grip strength. The optimized sensor can detect grip strength with high sensitivity. The hardness of the device was shown to increase sensitivity when healthy humans performed manual exercises and completed digital tasks. Providing patients with these devices can help monitor their rehabilitation following hand injuries or neurological disorders. This can be done through self-led at-home therapy which has been shown to improve treatment, engagement, long-term lifestyle adherence, while avoiding repeated visits to clinics which plays an important role in frequency of therapy, effectiveness, and accessibility.Open Acces

Development of a Micro Recording Probe for Measurements of Neuronal Activity in Freely Moving Animals

To discover general principles of biological sensorimotor control, insects have become remarkably successful model systems. In contrast to highly complex mammals, the functional organization of the insect nervous system in combination with a well-defined behavioural repertoire turned out to provide ideal conditions for quantitative studies into the neural control of behaviour. In addition, the search for biologically inspired control algorithms has further accelerated research into the neuronal mechanisms underlying flight and gaze stabilization, especially in blowflies. However, recording the neuronal activity in freely behaving insects, in particular in comparatively small insects such as blowflies, still imposes a major technical challenge. To date, electrophysiological recordings in unrestrained flies have never been achieved. This thesis describes the design and testing of a micro recording probe to be used for monitoring extracellular electrical activity in the nervous system of freely moving blowflies. In principle, this probe could also be used to study the neuronal control of behaviour in any other animal species the size of which is bigger than that of a blowfly. The nature of neuronal signals and the objective to record neuronal activity from behaving blowflies puts massive constraints on the specifications of the probe. I designed a differential amplifier with high gain, high linearity, low noise, and low power consumption. To fit the probe in the blowfly‟s head capsule and in direct contact with the animal‟s brain, the amplifier is on an unpackaged die. The neuronal signals are in the order of a few 100s of μV in amplitude. To be able to digitize such small signals >1000 times amplification is desirable. The small signal amplitudes also necessitate minimization of circuit noise. Linearity is necessary to prevent distortion of signal shape. Since connecting wires would impede movement of the animal, the probe would need to be powered by batteries. Therefore, low power is needed for two reasons: (i) to increase battery life, and therefore recording time, and (ii) because heat caused by power expenditure may damage the blowfly‟s brain or change its behaviour. To reduce power consumption I used CMOS transistors biased in the subthreshold region and a 2.2 V low power supply. The amplifier was characterized after fabrication by means of measuring its frequency response, linearity, and noise. I also recorded signals from a blowfly's brain and compared the performance of my recording probe with the performance of a high specification commercial amplifier in the time and frequency domains

The Fifth NASA Symposium on VLSI Design

The fifth annual NASA Symposium on VLSI Design had 13 sessions including Radiation Effects, Architectures, Mixed Signal, Design Techniques, Fault Testing, Synthesis, Signal Processing, and other Featured Presentations. The symposium provides insights into developments in VLSI and digital systems which can be used to increase data systems performance. The presentations share insights into next generation advances that will serve as a basis for future VLSI design

Technology 2003: The Fourth National Technology Transfer Conference and Exposition, volume 2

Proceedings from symposia of the Technology 2003 Conference and Exposition, Dec. 7-9, 1993, Anaheim, CA, are presented. Volume 2 features papers on artificial intelligence, CAD&E, computer hardware, computer software, information management, photonics, robotics, test and measurement, video and imaging, and virtual reality/simulation