W. A. Atherton

Bio: W. A. Atherton is an academic researcher. The author has contributed to research in topics: Electronics & Integrated circuit. The author has an hindex of 1, co-authored 1 publications receiving 3 citations.

Miniaturization of Electronics

Abstract: Miniaturization has made it possible for electronics to penetrate society more widely and deeply than ever before. Pocket calculators, electronic watches, miniature colour television receivers and the like are only some of the examples of the miniaturization of electronics of which the general public first became aware. Even before they came along, miniaturized electronic systems had made a significant impact in military, industrial, and commercial areas. Miniaturization helped in the exploration of space, in communications, in the control of machinery and processes, and in the handling and processing of data. The miniaturization of electronics is sometimes regarded as a somewhat late development that derives from the integrated circuit; yet miniaturization on the grounds of size, weight, and power requirements was under way long before the integrated circuit was invented and even before the transistor became commercially available. Valve (vacuum-tube) manufacturers were remarkably successful in producing miniature and subminiature valves, some of them smaller than a present-day power transistor; and the screen printing of resistive and other passive components, and the concept of electronic modules, helped to bring about smaller electronic systems. Yet the big acceleration towards microelectronics did indeed begin with the invention of the integrated circuit, when at first small and later large circuits were formed on a single chip of silicon. The net result was systems far larger and far more complex than could even have been dreamed of before.

Micro/nanostructured TiNb2O7-related electrode materials for high-performance electrochemical energy storage: recent advances and future prospects

Abstract: The increasing demand for large-scale electrochemical energy storage, such as lithium ion batteries (LIBs) for electric vehicles and smart grids, requires the development of advanced electrode materials. Ti–Nb–O compounds as some of the most promising intercalation-type anode materials have attracted a lot of attention owing to their high theoretical capacity (388–399 mA h g−1) arising from the multiple redox pairs (Ti4+/Ti3+, Nb5+/Nb4+, and Nb4+/Nb3+), high safety, and superior cycling stability. However, their intrinsic low electronic conductivity and slow solid-state ion diffusion lead to unsatisfactory rate performance. To overcome these drawbacks, various efficient strategies have been proposed to improve the performance of Ti–Nb–O compounds, especially TiNb2O7. This Review aims to provide rational understanding of how structural engineering approaches (e.g., dimensional/morphological control, doping/hybridizing with exotic elements/components, carbon coating/compositing, etc.) improve the electrochemical properties of micro/nanostructured TiNb2O7-based anode materials. In addition, other Ti–Nb–O compounds with different compositions as anodes for LIBs and micro/nanostructured TiNb2O7-based anodes for other energy storage systems (sodium-ion batteries, hybrid supercapacitors, and vanadium redox flow batteries) are discussed. Finally, the challenges and opportunities for micro/nanostructured TiNb2O7-related electrode materials for high-performance energy storage applications are highlighted.

Peak Temperature Mitigation of a Multimicrochannel Evaporator Under Transient Heat Loads

Abstract: Microchannel flow boiling has shown great cooling potential with steady-state studies demonstrating the capability to dissipate heat fluxes over 1 kW cm−2. However, most microelectronic devices undergo transient heat loads involving cold startups or pulse-like power operation. Transient heating events in low thermal resistance, low thermal capacity cold plates may exacerbate boiling instabilities and result in device damage or failure due to local dryout conditions. Currently, limited studies are investigating these effects and potential mitigation strategies. In this study, step function, or pulsed, and ramped heat loads are investigated on a multimicrochannel silicon evaporator using R134a under a range of heat fluxes and ramping rates. The transient temperature response of the base heater is recorded using a calibrated infrared (IR) camera, while fluid flow visualization is captured using a video camera microscope. Pulsed heat loads resulted in a large temperature overshoot in the test section until the fluid reached the onset of nucleate boiling (ONB), while significant vapor backflow is observed despite the presence of channel inlet restrictions. Steady boiling is eventually reached and vapor backflow is suppressed. The magnitude of the temperature overshoot is observed to be strongly dependent on peak heat flux. In contrast, ramped heat loads resulted in lower peak temperature rises before ONB as well as significantly reduced vapor backflow compared to the pulsed heat loads.