Abstract: Energy harvesting is an emerging technology with applications to handheld, portable and implantable electronics. Harvesting ambient vibration energy through piezoelectric (PE) means is a popular energy harvesting technique that can potentially supply 10 to 100's of µW of available power [1]. One of the limitations of existing PE harvesters is in their interface circuitry. Commonly used full-bridge rectifiers and voltage doublers [2] severely limit the electrical power extractable from a PE harvesting element. Further, the power consumed in the control circuits of these harvesters reduces the amount of usable electrical power. In this paper, a bias-flip rectifier that can improve upon the power extraction capability of existing full-bridge rectifiers by up to 4.2× is presented. An efficient control circuit with embedded DC-DC converters that can share their filter inductor with the bias-flip rectifier thereby reducing the volume and component count of the overall solution is demonstrated.

Abstract: Flexible-electronics is rapidly finding many main-stream applications where low-cost, ruggedness, light weight, unconventional form factors and ease of manufacturability are just some of the important advantages over their conventional rigid-substrate counterparts. Flexible Electronics: Materials and Applications surveys the materials systems and processes that are used to fabricate devices that can be employed in a wide variety of applications, including flexible flat-panel displays, medical image sensors, photovoltaics, and electronic paper. Materials discussed range from polymeric semiconductors to nanotube transparent conductors, highlighting the important characteristics of each system and their target applications. An overview of the performance benchmarks for the different materials is given in order to allow a direct comparison of these different technologies. Furthermore, the devices and processes most suitable for given applications in flexible electronics are identified. Topics covered include: An overview and history of flexible electronics Novel materials for solution-processable thin-film electronic devices and their properties Low-temperature processing of conventional materials and devices on plastic foils Novel techniques, such as printing and roll-to-roll processing, for large-area flexible electronics manufacturing Materials and device physics relevant to flexible electronics Device integration on flexible substrates Mechanical and electronic characteristics for thin-film transistors and nano-scale transparent conductors on flexible platforms Applications towards flexible displays, sensors, actuators, solar energy, radio-frequency identification, and micro-electro-mechanical systems Written by leading researchers in the field, Flexible Electronics: Materials and Applications serves as a reference for researchers, engineers, and students interested in the characteristics, capabilities, and limitations of these exciting materials and emerging applications.

Abstract: Electronic devices based on carbon nanotubes are among the candidates to eventually replace silicon-based devices for logic applications. Before then, however, nanotube-based radiofrequency transistors could become competitive for high-performance analogue components such as low-noise amplifiers and power amplifiers in wireless systems. Single-walled nanotubes are well suited for use in radiofrequency transistors because they demonstrate near-ballistic electron transport and are expected to have high cut-off frequencies. To achieve the best possible performance it is necessary to use dense arrays of semiconducting nanotubes with good alignment between the nanotubes, but techniques that can economically manufacture such arrays are needed to realize this potential. Here we review progress towards nanotube electronics for radiofrequency applications in terms of device physics, circuit design and the manufacturing challenges. Arrays of semiconducting single-walled carbon nanotubes are well suited for use in radiofrequency transistors. This article reviews progress towards nanotube-based radiofrequency devices in terms of device physics, circuit design and manufacturing challenges.

Abstract: Materials and design strategies for stretchable silicon integrated circuits that use non-coplanar mesh layouts and elastomeric substrates are presented. Detailed experimental and theoretical studies reveal many of the key underlying aspects of these systems. The results shpw, as an example, optimized mechanics and materials for circuits that exhibit maximum principal strains less than 0.2% even for applied strains of up to approximately 90%. Simple circuits, including complementary metal-oxide-semiconductor inverters and n-type metal-oxide-semiconductor differential amplifiers, validate these designs. The results suggest practical routes to high-performance electronics with linear elastic responses to large strain deformations, suitable for diverse applications that are not readily addressed with conventional wafer-based technologies.

Abstract: Materials and methods to achieve electronics intimately integrated on the surfaces of substrates with complex, curvilinear shapes are described. The approach exploits silicon membranes in circuit mesh structures that can be deformed in controlled ways using thin, elastomeric films. Experimental and theoretical studies of the micromechanics of such curvilinear electronics demonstrate the underlying concepts. Electrical measurements illustrate the high yields that can be obtained. The results represent significant experimental and theoretical advances over recently reported concepts for creating hemispherical photodetectors in electronic eye cameras and for using printable silicon nanoribbons/membranes in flexible electronics. The results might provide practical routes to the integration of high performance electronics with biological tissues and other systems of interest for new applications.

Abstract: Fuel cells (FCs) hold great promise as a clean energy conversion technology. A large research effort is underway to develop the FC for applications ranging from small portable electronic devices to automotive transport, as well as residential combined heat and power supplies. These applications have a large emerging market and widespread adoption should lead to a reduced dependence on fossil fuels as well as encourage the development of a hydrogen economy. FCs produce low DC voltage, so that it is most often connected to electric networks through a step-up DC/DC converter. This article first introduces electrical characteristics, power electronic requirements, and different types of FCs and is then followed by a discussion of the various topologies of step-up DC/DC converters used for FCs' power-conditioning system. The examinations of several different approaches to power-conditioning systems for single and multiple FC combinations have been reviewed. High-power DC distributed power systems supplied by FC invokes the need to parallel power modules with interleaving technique. By method of the parallel converter modules with interleaving algorithm for an FC generatorfor high-power applications, inductor size (ferrite core and Litzwire) are simple to design and fabricate, and the FC ripple current can be virtually reduced to zero. As a result, the FC mean current is nearly equal to the FC rms current. The main drawback of the multiphase approach is added circuit complexity, requiring measurement and balancing of each phase current as the larger number of control components illustrates.

Abstract: Introduction.- Semiconductors.- Basic Semiconductor Structures.- Semiconductors as Detectors.- Detectors for Energy and Radiation Level Measurement.- Detectors for Position and Energy Measurement.- Front and Electronics.- Device Simulation.- Integration of Detector and Electronics.- Detectors with Intrinsic Amplification.- Fabrication Technology and Device Characterization.- Radiation Hardness of Detectors and Electronics.- Optimal Choice of Detectors and Electronics.- Summary and Outlook.

Abstract: Various heat-sinked components and methods of making heat-sinked components are disclosed where diamond in thermal contact with one or more heat-generating components are capable of dissipating heat, thereby providing thermally-regulated components. Thermally conductive diamond is provided in patterns capable of providing efficient and maximum heat transfer away from components that may be susceptible to damage by elevated temperatures. The devices and methods are used to cool flexible electronics, integrated circuits and other complex electronics that tend to generate significant heat. Also provided are methods of making printable diamond patterns that can be used in a range of devices and device components.

Abstract: Exemplary embodiments are directed to retrofitting existing electronic devices for wireless power transfer and near-field communication. Retrofitting circuitry includes an antenna for receiving a signal from an external source, and conversion circuitry for converting the signal to be used by an electronic device. The antenna and conversion circuitry are configured to retrofit to the electronic device, where the electronic device did not originally include the antenna or conversion circuitry. The antenna and conversion circuitry may be configured to receive and convert the signal to generate wireless power for the electronic device. The antenna and the conversion circuitry may also be configured to enable the electronic device to send and receive near-field communication data.

Abstract: As part of the U.S. Department of Energy's (DOE's) Power Electronics and Electric Machines Program area, the DOE's National Renewable Energy Laboratory (NREL) is currently leading a national effort to develop next-generation cooling technologies for hybrid vehicle electronics. Spray cooling has been identified as a potential solution that can dissipate 150-200 W/cm2 while maintaining the chip temperature below 125degC. This paper explores the viability and implementation of this cooling scheme. First, commercial coolants are assessed for their suitability to this application in terms of thermal, environmental, and safety concerns and material compatibility. In this assessment, HFE-7100 is identified as the optimum coolant in all performance categories. Next, spray models are used to determine the HFE-7100 spray conditions that meet such stringent heat dissipation requirements. These findings are verified experimentally, demonstrating that spray cooling is a viable thermal management solution for hybrid vehicle electronics.

Abstract: Techniques are described herein that are capable of using an efficiency indicator for increasing efficiency of a wireless power transfer. A wireless power transfer system includes features that allow the system to be deployed in public spaces such as airports or in commercial establishments such as restaurants or hotels to allow a user to recharge one or more portable electronic devices while away from home. The system may provide an efficiency indicator to a portable electronic device that specifies a recommended position of the portable electronic device. The recommended position may correspond to an efficiency with respect to the wireless power transfer that is greater than an efficiency with respect to the wireless power transfer that corresponds to a position of the portable electronic device. The portable electronic device may generate a sensory signal that indicates the recommended position with reference to the position of the portable electronic device.

Abstract: Systems, methods, and devices for simplified resource-sharing with electronic devices are provided. For example, a method for using at least one resource of a variety of electronic devices from another electronic device may include receiving resource-sharing information associated with a resource-sharing electronic device via near field communication, determining a resource-sharing scheme for using the resources of the resource-sharing electronic device based on the resource-sharing information, and sharing at least one resource of the resource-sharing electronic device using the determined resource-sharing scheme. The resource-sharing information may be received from a near field communication interface of the resource-sharing electronic device or from a radio frequency identification tag associated with the resource-sharing electronic device.

Abstract: A questionnaire survey was carried out to determine the industrial requirements and expectations of reliability in power electronic converters. According to the survey, power semiconductor devices ranked the most fragile components. It was concluded that main stresses were from the environment, transients and heavy loads, which should be considered during power electronic system design and normal operation. Further analyses suggest that power device reliability is a key issue and power electronic converter design is correlated with failure costs.

Abstract: Computer-aided design and manufacture software and hardware automate garment and fashion definition and production. Configurable garment includes ornamental element, pattern display, and personal identifier and wireless sensor electronics.

Abstract: Electronics cooling research has been largely focused on high heat flux removal from computer chips in the recent years. However, the equally important field of high-power electronic devices has been experiencing a major paradigm shift from air cooling to liquid cooling over the last decade. For example, multiple 250-W insulated-gate bipolar transistors used in a power drive for a 7000-HP motor used in pumping or in locomotive traction devices would not be sufficiently cooled with air-cooling techniques. Another example is a “hockey puck” SCR of 63 mm diameter used to drive an electric motor that could dissipate over 1500 W and is difficult to cool with air because of the shape of the device. Other devices include radio-frequency generators, industrial battery chargers, printing press thermal and humidity control equipment, traction devices, mining devices, crude oil extraction equipment, magnetic resonance imaging, and railroad engines. This article classifies the cold plates into four types: formed tube...

Abstract: Semiconductors are key materials in modern electronics and are widely used to build, for instance, transistors in integrated circuits as well as thermoelectric materials for energy conversion, and there is a tremendous interest in the development and improvement of novel materials and technologies to increase the performance of electronic devices and thermoelectrics. Tetramorphic Ag10Te4Br3 is a semiconductor capable of switching its electrical properties by a simple change of temperature. The combination of high silver mobility, a small non-stoichiometry range and an internal redox process in the tellurium substructure causes a thermopower drop of 1,400 μV K−1, in addition to a thermal diffusivity in the range of organic polymers. The capability to reversibly switch semiconducting properties from ionic to electronic conduction in one single compound simply by virtue of temperature enables novel electronic devices such as semiconductor switches. Switching between n- and p-type conduction in a semiconductor can be done through doping. A fundamentally different behaviour has now been observed in Ag10Te4Br3, as a transition from ionic to electronic conduction is achieved simply by heating, which could be used for switches or in novel electronic devices.

Abstract: Electronics components have an increasingly critical role in avionics systems and in the development of future aircraft systems. Prognostics of such components is becoming a very important research field as a result of the need to provide aircraft systems with system level health management information. This paper focuses on a prognostics application for electronics components within avionics systems, and in particular its application to an Isolated Gate Bipolar Transistor (IGBT). This application utilizes the remaining useful life prediction, accomplished by employing the particle filter framework, leveraging data from accelerated aging tests on IGBTs. These tests induced thermal-electrical overstresses by applying thermal cycling to the IGBT devices. In-situ state monitoring, including measurements of steady-state voltages and currents, electrical transients, and thermal transients are recorded and used as potential precursors of failure.

Abstract: Portable electronics have fueled the rich emergence of new applications including multi-media handsets, ubiquitous smart sensors and actuators, and wearable or implantable biomedical devices. New ultra-low power circuit techniques are constantly being proposed to further improve the energy efficiency of electronic circuits. A critical part of these energy conscious systems are the energy processing and power delivery circuits that interface with the energy sources and provide conditioned voltage and current levels to the load circuits. These energy processing circuits must maintain high efficiency and reduce component count for the final solution to be attractive from an energy, size and cost perspective. The first part of this work focuses on the development of on-chip voltage scalable switched capacitor DC-DC converters in digital CMOS processes. The converters are designed to deliver regulated scalable load voltages from 0.3V up to the battery voltage of 1.2V for ultra-dynamic voltage scaled systems. The efficiency limiting mechanisms of these on-chip DC-DC converters are analyzed and digital circuit techniques are proposed to tackle these losses. Measurement results from 3 test-chips implemented in 0.18μm and 65nm CMOS processes will be provided. The converters are able to maintain >75% efficiency over a wide range of load voltage and power levels while delivering load currents up to 8mA. An embedded switched capacitor DC-DC converter that acts as the power delivery unit in a 65nm subthreshold microcontroller system will be described. The remainder of the thesis deals with energy management circuits for battery-less systems. Harvesting ambient vibrational, light or thermal energy holds much promise in realizing the goal of a self-powered system. The second part of the thesis identifies problems with commonly used interface circuits for piezoelectric vibration energy harvesters and proposes a rectifier design that gives more than 4X improvement in output power extracted from the piezoelectric energy harvester. The rectifier designs are demonstrated with the help of a test-chip built in a 0.35μm CMOS process. The inductor used within the rectifier is shared efficiently with a multitude of DC-DC converters in the energy harvesting chip leading to a compact, cost-efficient solution. The DC-DC converters designed as part of a complete power management solution achieve efficiencies of greater than 85% even in the micro-watt 3 power levels output by the harvester. The final part of the thesis deals with thermal energy harvesters to extract electrical power from body heat. Thermal harvesters in body-worn applications output ultra-low voltages of the order of 10’s of milli-volts. This presents extreme challenges to CMOS circuits that are powered by the harvester. The final part of the thesis presents a new startup technique that allows CMOS circuits to interface directly with and extract power out of thermoelectric generators without the need for an external battery, clock or reference generators. The mechanically assisted startup circuit is demonstrated with the help of a test-chip built in a 0.35μm CMOS process and can work from as low as 35mV. This enables load circuits like processors and radios to operate directly of the thermoelectric generator without the aid of a battery. A complete power management solution is provided that can extract electrical power efficiently from the harvester independent of the input voltage conditions. With the help of closed-loop control techniques, the energy processing circuit is able to maintain efficiency over a wide range of load voltage and process variations. Thesis Supervisor: Anantha P. Chandrakasan Title: Professor of Electrical Engineering and Computer Science

Abstract: Method of forming a radio frequency integrated circuit (RFIC) is provided. The RFIC comprises one or more electronic devices formed in a semiconductor substrate and one or more passive devices on a dielectric substrate, arranged in a stacking manner. Electrical shield structure is formed in between to shield electronic devices in the semiconductor substrate from the passive devices in the dielectric substrate. Vertical through-silicon-vias (TSVs) are formed to provide electrical connections between the passive devices in the dielectric substrate and the electronic devices in the semiconductor substrate.

Abstract: Printed electronics is a promising technology that has received tremendous interest as a mass production process for low-cost electronics devices, because it increases manufacturing flexibility and decreases manufacturing costs The low process temperatures allow the use of flexible substrate materials, such as paper or plastics, suitable for a reel-to-reel process In this paper we focus on high-frequency properties of printed electronics We designed and manufactured a transmission line and a patch antenna for 24 GHz ISM band One test set was manufactured using conventional etching technique for a reference with a metal thickness of 17 μ m Two other test cases were fabricated using an inkjet-based printing technique that is described in more detail later in this paper Printed patterns have thicknesses of 25 and 05 μ m This work evaluates the suitability of printed electronics in high-frequency applications Insertion loss in the 60 mm-length transmission line was 01 dB higher in the case of the printed (thick) line than in that of the etched line Furthermore, impedance matching bandwidth was almost the same in all antennas, although a small decrease in radiation properties was found

Abstract: An electronic device may be provided with a conductive housing. The conductive housing may be formed from a metal. Slots may be formed in the housing. The slots may serve as an antenna and may be fed using an antenna feed structure within the electronic device housing. The electronic device may have a frame to which housing structures are attached and may have a stand or other support structure. The frame may be used to mount a display, to support housing walls, to support clutch barrel structures, etc. The slots may be formed in the frame or in a space between the frame and the housing walls. The slots or other antenna structures may also be formed in the stand. Multiple slots may be used together to support operations in two or more communications bands. There may be multiple dual slot antennas in the electronic device.

Abstract: A method of fabricating a resistor-drive transistor architecture for a printhead of a printer, by depositing printer communication and drive electronics on the printhead. The drive electronics are positioned within a range of one to sixty microns from correlated resistors.

Abstract: A blood testing apparatus has a test member and a laser source configured to produce a wound from which blood flows. The laser source produces at least a cutting wavelength, and a coagulation wavelength. Electronics for analysis and a display are provided. The test member, laser source, electronics and display form a glucose monitoring system that is integrated in a single apparatus.

Abstract: Liquid-cooled electronics apparatuses and methods are provided. The cooled electronics apparatuses include a liquid-cooled cold rail and an electronics subassembly. The liquid-cooled cold rail has a thermally conductive structure and a coolant-carrying channel extending within and cooling the thermally conductive structure. The electronics subassembly includes an electronics card(s) and one or more thermal transfer plates. The electronics card(s) includes electronic devices to be cooled, and the one or more thermal transfer plates are each rigidly affixed to one or more electronic devices of the electronics card(s). Each thermal transfer plate is thermally conductive and couples the electronics subassembly to the liquid-cooled cold rail to thermally interface the one or more electronic devices to the liquid-cooled cold rail to facilitate cooling of the electronic devices. In one embodiment, the electronics subassembly includes multiple interleaved electronics cards and thermal transfer plates.

Abstract: New electronic materials have the potential to enable wearable computers, personal health monitors, wall-scale displays and other systems that are not easily achieved with established wafer based technologies. A traditional focus of this field is on the development of materials for circuits that can be formed on bendable substrates, such as sheets of plastic or steel foil. More recent efforts seek to achieve similar systems on fully elastic substrates for electronics that can be stretched, compressed, twisted and deformed in ways that are much more extreme than simple bending. This article highlights some recent progress in this area, with an emphasis on materials approaches and demonstrated devices.