A practical WSI experimental programme

At Brunel University, research has been underway for several years to assess the architectural, electrical and physical benefits and constraints of the WASP wafer-scale Associative String Processor (ASP). This is intended to implement a massively parallel processor entirely within the constraints of WSI. WASP 1 and WASP 2 were the technology demonstrators of the UK funded Alvey programme (starting 1984), researching fundamental design methodologies for WSI. They are both examples of the Associative String Processor (ASP) architecture, developed by Brunel University. Further demonstrators are currently funded by a 31/2-year US ONR IS&T programme (starting 1987), involving both further technology demonstration, applications research and fundamental packaging and manufacturing design issue

Investigation into the wafer-scale integration of fine-grain parallel processing computer systems

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This thesis investigates the potential of wafer-scale integration (WSI) for the implementation of low-cost fine-grain parallel processing computer systems. As WSI is a relatively new subject, there was little work on which to base investigations. Indeed, most WSI architectures existed only as untried and sometimes vague proposals. Accordingly, the research strategy approached this problem by identifying a representative WSI structure and architecture on which to base investigations. An analysis of architectural proposals identified associative memory to be general purpose parallel processing component used in a wide range of WSI architectures. Furthermore, this analysis provided a set of WSI-level design requirements to evaluate the sustainability of different architectures as research vehicles. The WSI-ASP (WASP) device, which has a large associative memory as its main component is shown to meet these requirements and hence was chosen as the research vehicle. Consequently, this thesis addresses WSI potential through an in-depth investigation into the feasibility of implementing a large associative memory for the WASP device that meets the demanding technological constraints of WSI. Overall, the thesis concludes that WSI offers significant potential for the implementation of low-cost fine-grain parallel processing computer systems. However, due to the dual constraints of thermal management and the area required for the power distribution network, power density is a major design constraint in WSI. Indeed, it is shown that WSI power densities need to be an order of magnitude lower than VLSI power densities. The thesis demonstrates that for associative memories at least, VLSI designs are unsuited to implementation in WSI. Rather, it is shown that WSI circuits must be closely matched to the operational environment to assure suitable power densities. These circuits are significantly larger than their VLSI equivalents. Nonetheless, the thesis demonstrates that by concentrating on the most power intensive circuits, it is possible to achieve acceptable power densities with only a modest increase in area overheads.SER

Self-organising techniques for tolerating faults in 2-dimensional processor arrays

This thesis is concerned with research into techniques for tolerating the defects which inevitably occur in integrated circuits during processing. The research is motivated by the desire to permit the fabrication of very large (> 1cm²) integrated circuits having a viable yield, using standard chip processing lines. Attention is focussed on 2-dimensional arrays of identical processing elements with nearest-neighbour, orthogonal interconnections, and techniques for configuring such arrays in the presence of faults are investigated. In particular, novel algorithms based on the concept of self-organisation are proposed and studied in detail. The algorithms involve associating a small amount of control logic with each processing element in the array. The extra logic allows the processing elements to communicate with each other and come to a collective decision about how working processors should best be interconnected. The concept has been studied in considerable depth and the implications of the algorithms in a practical system have been thoroughly considered and demonstrated by construction of a small array at printed circuit board level, complete with software controlled testing procedures. The thesis can be considered in four main parts as follows. The first part (chapters 1 to 4) starts by presenting the objectives of the research and then motivates it by examining the increasing need for processor arrays. The difficulty of implementing such arrays as monolithic circuits due to integrated circuit defects is then considered. This is followed by a review of published work on hardware fault tolerance for regular arrays of processors. The second part (chapters 5 and 6) is devoted to the concept of self-organisation in processor arrays and includes a detailed description and evaluation of the algorithms followed by a comparison with other published techniques. Considerations such as hardware requirements and overheads, reducing the vulnerability of critical circuitry, self-testing, and the construction of the demonstrator are covered in the third part (chapters 7 to 10). The fourth part (chapters 11 and 12) considers potential applications for the research in both monolithic and non-monolithic systems. Finally, the conclusions and some suggestions for further work are presented

Microoptical multi aperture imaging systems

Die Verkleinerung digitaler Einzelapertur-Abbildungssysteme erreicht aktuell physikalische sowie technische Limits. Die Miniaturisierung führt zu einer Verringerung sowohl des Auflösungsvermögens als auch des Signal-Rausch-Verhältnisses. Einen Ausweg zeigen die Prinzipien der kleinsten in der Natur bekannten Sehsysteme - die Facettenaugen. Die parallelisierte Anordnung einer großen Anzahl von Optiken ermöglicht, trotz der geringen Baugröße, eine große Informationsmenge aus einem ausgedehnten Gesichtsfeld zu übertragen. Ziel ist es, die Vorteile natürlicher Facettenaugen zu analysieren und diese zur Überwindung aktueller Grenzen der Miniaturisierung von digitalen Kameras zu adaptieren. Durch die Synergie von Optik, Opto-Elektronik und Bildverarbeitung wird die Miniaturisierung unter Erreichung praxisrelevanter Parameter angestrebt. Dafür wurde eine systematische Einteilung bereits bekannter und neuartiger Prinzipien von Multiapertur-Abbildungssystemen vorgenommen. Das grundlegende Verständnis der Vor- und Nachteile sowie des Skalierungsverhaltens der verschiedenen Ansätze ermöglichte die detaillierte Untersuchung der zwei erfolgversprechendsten Systemklassen. Für die Auslegung der Multiapertur-Optiken wurde eine Kombination aus Ansätzen des klassischen Optikdesigns und neuen semi-automatisierten Simulations- und Optimierungsmethoden mittels Ray-Tracing angewandt. Die mit natürlichen Facettenaugen vergleichbare Größe der Optiken ermöglichte die Verwendung mikrooptischer Herstellungsverfahren im Wafermaßstab. Es wurden Prototypen experimentell untersucht und die simulierten Systemparameter mit Hilfe der für die Multiapertur Anordnungen angepassten Messmethoden bestätigt. Die dargestellten Lösungen demonstrieren grundsätzlich neue Ansätze für den Bereich der hochauflösenden, miniaturisierten Abbildungsoptik, die kleinste Baulängen bei gegebenem Auflösungsvermögen erzielen. Somit sind sie im Stande die Skalierungslimits der Einzelapertur-Abbildungsoptik zu überwinden

Microoptical multi aperture imaging systems

Die Verkleinerung digitaler Einzelapertur-Abbildungssysteme erreicht aktuell physikalische sowie technische Limits. Die Miniaturisierung führt zu einer Verringerung sowohl des Auflösungsvermögens als auch des Signal-Rausch-Verhältnisses. Einen Ausweg zeigen die Prinzipien der kleinsten in der Natur bekannten Sehsysteme - die Facettenaugen. Die parallelisierte Anordnung einer großen Anzahl von Optiken ermöglicht, trotz der geringen Baugröße, eine große Informationsmenge aus einem ausgedehnten Gesichtsfeld zu übertragen. Ziel ist es, die Vorteile natürlicher Facettenaugen zu analysieren und diese zur Überwindung aktueller Grenzen der Miniaturisierung von digitalen Kameras zu adaptieren. Durch die Synergie von Optik, Opto-Elektronik und Bildverarbeitung wird die Miniaturisierung unter Erreichung praxisrelevanter Parameter angestrebt. Dafür wurde eine systematische Einteilung bereits bekannter und neuartiger Prinzipien von Multiapertur-Abbildungssystemen vorgenommen. Das grundlegende Verständnis der Vor- und Nachteile sowie des Skalierungsverhaltens der verschiedenen Ansätze ermöglichte die detaillierte Untersuchung der zwei erfolgversprechendsten Systemklassen. Für die Auslegung der Multiapertur-Optiken wurde eine Kombination aus Ansätzen des klassischen Optikdesigns und neuen semi-automatisierten Simulations- und Optimierungsmethoden mittels Ray-Tracing angewandt. Die mit natürlichen Facettenaugen vergleichbare Größe der Optiken ermöglichte die Verwendung mikrooptischer Herstellungsverfahren im Wafermaßstab. Es wurden Prototypen experimentell untersucht und die simulierten Systemparameter mit Hilfe der für die Multiapertur Anordnungen angepassten Messmethoden bestätigt. Die dargestellten Lösungen demonstrieren grundsätzlich neue Ansätze für den Bereich der hochauflösenden, miniaturisierten Abbildungsoptik, die kleinste Baulängen bei gegebenem Auflösungsvermögen erzielen. Somit sind sie im Stande die Skalierungslimits der Einzelapertur-Abbildungsoptik zu überwinden

Biomimetische Strukturierung von Silikonmaterialien für die Beeinflussung von Zellverhalten und für dehnungsversteifende Materialien

In the first part of this thesis research, an artificial extra-cellular matrix formed the basis for experiments with a pathogenic species of amoeba, Acanthamoeba castellanii. In order to find new therapeutic approaches to fighting diseases caused by this species, the migratory behavior of Acanthamoeba castellanii in micro-pillar structures made of silicone, which were used to mimic the confined environment of an extra-cellular matrix, was explored. For the experiments, amoebae ingested microparticles of varying shapes. While it was found that sphere-shaped particles with a diameter smaller than the distance between the micro-pillars did not impact migration behavior, absorption of larger particles by Acanthamoeba castellanii caused migration to be strongly reduced. However, in some instances, it appeared that Acanthamoeba castellanii was nonetheless able to successfully navigate the pillar structures. These observations could serve as a basis for developing methods aimed at capturing amoebae before they can enter the human body. In the second part of this thesis, the focus was on developing a material with specific mechanical properties geared at mimicking an intra-cellular effect, namely the cross-linking of fibers within the cytoskeleton as a reaction to deformation of the cell and thereby increasing its stiffness. Emulating this effect, a strain-stiffening material was developed using a flexible, slat-structured silicone. When the material is elongated, these slats touch, thereby leading to a stiffening of the material. Employing finite element analysis, the degree to which various geometrical factors of the structure and friction between the slats affect the material’s stiffening behavior was examined, and the results were verified using tensile tests. The structure that resulted from my efforts yields a stiffening behavior that is material-independent, speed-independent and reversible, and that occurs also when the material is elongated.Eine künstliche extrazelluläre Matrix war die Basis für Experimente mit der pathogenen Amöbenspezies Acanthamoeba castellanii im ersten Teil der Arbeit. Auf der Suche nach neuartigen therapeutischen Ansätzen gegen Krankheiten, die von dieser Spezies verursacht werden, wurde deren Migrationsverhalten in mikrostrukturieren Säulenstrukturen aus flexiblem Silikon, die die beengende Umgebung der extrazellulären Matrix darstellen sollten, untersucht. Im Rahmen der Experimente haben die Amöben Mikropartikel mit verschiedenen Geometrien aufgenommen. Kugelförmige Partikel mit einem Durchmesser, der kleiner als der Abstand zwischen den Säulen ist, beeinflussten die Migration in den Strukturen nicht. In den Fällen, in denen Acanthamoeba castellanii größere Partikel aufgenommen hat, war die Migration in den Strukturen stark reduziert. In einigen Fällen konnten jedoch alternative Herangehensweisen beobachtet werden, die trotzdem Migration durch die Säulenstrukturen erlaubten. Die Imitation eines intrazellulären Effektes war die Grundlage für die Entwicklung eines Materials mit definierten mechanischen Eigenschaften im zweiten Teil der Arbeit. Die Fähigkeit von Zellen, als Reaktion auf eine Deformation Fasern im Zytoskelett zu vernetzen und somit ihre Steifigkeit zu erhöhen, wurde in dehnungsversteifenden Materialien nachgestellt. Es wurde eine Struktur aus flexiblem Silikon entwickelt, die eine Lamellenstruktur enthält. Diese Lamellen berühren sich im Fall einer Elongation des Materials und führen zu einer Versteifung des Materials. Es wurde mit Hilfe von Finite Elemente Analysen der Einfluss sowohl diverser geometrische Faktoren der Struktur, als auch der Reibung zwischen den Lamellen auf das Versteifungsverhalten des Materials untersucht. Die Ergebnisse wurden mit Hilfe von realen Zugversuchen verifiziert. Die entwickelte Struktur bietet ein materialunabhängiges, geschwindigkeitsunabhängiges, reversibles Versteifungsverhalten, das zudem auch bei einer Elongation des Materials auftritt

Program Annual Technology Report: Cosmic Origins Program Office

What is the Cosmic Origins (COR) Program? From ancient times, humans have looked up at the night sky and wondered: Are we alone? How did the universe come to be? How does the universe work? COR focuses on the second question. Scientists investigating this broad theme seek to understand the origin and evolution of the universe from the Big Bang to the present day, determining how the expanding universe grew into a grand cosmic web of dark matter enmeshed with galaxies and pristine gas, forming, merging, and evolving over time. COR also seeks to understand how stars and planets form from clouds in these galaxies to create the heavy elements that are essential to life, starting with the first generation of stars to seed the universe, and continuing through the birth and eventual death of all subsequent generations of stars. The COR Programs purview includes the majority of the field known as astronomy

Microoptical artificial compound eyes

Two different artificial compound eye concepts for compact vision systems have been investigated in detail: The artificial apposition compound eye objective and the cluster eye. Optical design methods and characterization tools were developed or modified to allow the layout and analysis of the microoptical imaging systems which were fabricated for the first time by microoptics technology

Goddard's Astrophysics Science Division Annual Report 2011

The Astrophysics Science Division(ASD) at Goddard Space Flight Center(GSFC)is one of the largest and most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum from gamma rays to radiowavelengths as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors, space-based interferometry, high contract imaging techniques to serch for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research, and provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and suppport the astronomical community, and enable future missions by conceiving new conepts and inventing new technologies

DEVELOPMENT OF FUNCTIONAL NANOCOMPOSITE MATERIALS TOWARDS BIODEGRADABLE SOFT ROBOTICS AND FLEXIBLE ELECTRONICS

World population is continuously growing, as well as the influence we have on the ecosystem\u2019s natural equilibrium. Moreover, such growth is not homogeneous and it results in an overall increase of older people. Humanity\u2019s activity, growth and aging leads to many challenging issues to address: among them, there are the spread of suddenly and/or chronic diseases, malnutrition, resource pressure and environmental pollution. Research in the novel field of biodegradable soft robotics and electronics can help dealing with these issues. In fact, to face the aging of the population, it is necessary an improvement in rehabilitation technologies, physiological and continuous monitoring, as well as personalized care and therapy. Also in the agricultural sector, an accurate and efficient direct measure of the plants health conditions would be of help especially in the less-developed countries. But since living beings, such as humans and plants, are constituted by soft tissues that continuously change their size and shapes, today\u2019s traditional technologies, based on rigid materials, may not be able to provide an efficient interaction necessary to satisfy these needs: the mechanical mismatch is too prohibitive. Instead, soft robotic systems and devices can be designed to combine active functionalities with soft mechanical properties that can allow them to efficiently and safely interact with soft living tissues. Soft implantable biomedical devices, smart rehabilitation devices and compliant sensors for plants are all applications that can be achieved with soft technologies. The development of sophisticated autonomous soft systems needs the integration on a unique soft body or platform of many functionalities (such as mechanical actuation, energy harvesting, storage and delivery, sensing capabilities). A great research interest is recently arising on this topic, but yet not so many groups are focusing their efforts in the use of natural-derived and biodegradable raw materials. In fact, resource pressure and environmental pollution are becoming more and more critical problems. It should be completely avoided the use of in exhaustion, pollutant, toxic and non-degradable resources, such as lithium, petroleum derivatives, halogenated compounds and organic solvents. So-obtained biodegradable soft systems and devices could then be manufactured in high number and deployed in the environment to fulfil their duties without the need to recover them, since they can safely degrade in the environment. The aim of the current Ph.D. project is the use of natural-derived and biodegradable polymers and substances as building blocks for the development of smart composite materials that could operate as functional elements in a soft robotic system or device. Soft mechanical properties and electronic/ionic conductive properties are here combined together within smart nanocomposite materials. The use of supersonic cluster beam deposition (SCBD) technique enabled the fabrication of cluster-assembled Au electrodes that can partially penetrate into the surface of soft materials, providing an efficient solution to the challenge of coupling conductive metallic layers and soft deformable polymeric substrates. In this work, cellulose derivatives and poly(3-hydroxybutyrate) bioplastic are used as building blocks for the development of both underwater and in-air soft electromechanical actuators that are characterized and tested. A cellulosic matrix is blended with natural-derived ionic liquids to design and manufacture completely biodegradable supercapacitors, extremely interesting energy storage devices. Lastly, ultrathin Au electrodes are here deposited on biodegradable cellulose acetate sheets, in order to develop transparent flexible electronics as well as bidirectional resistive-type strain sensors. The results obtained in this work can be regarded as a preliminary study towards the realization of full natural-derived and biodegradable soft robotic and electronic systems and devices