Electromechanical Computer Research Articles

High-Temperature-Operable Electromechanical Computing Units Enabled by Aligned Carbon Nanotube Arrays.

Nano/micro-electromechanical (NEM/MEM) contact switches have great potential as energy-efficient and high-temperature-operable computing units to surmount those limitations of transistors. However, despite recent advances, the high-temperature operation of the mechanical switch is not fully stable nor repetitive due to the melting and softening of the contact material in the mechanical switch. Herein, MEM switches with carbon nanotube (CNT) arrays capable of operating at high temperatures are presented. In addition to the excellent thermal stability of CNT arrays, the absence of a melting point of CNTs allows the proposed switches to operate successfully at up to 550 °C, surpassing the maximum operating temperatures of state-of-the-art mechanical switches. The switches with CNTs also show a highly reliable contact lifetime of over 1 million cycles, even at a high temperature of 550 °C. Moreover, symmetrical pairs of normally open and normally closed MEM switches, whose interfaces are initially in contact and separated, respectively, are introduced. Consequently, the complementary inverters and logic gates operating at high temperatures can be easily configured such as NOT, NOR, and NAND gates. These switches and logic gates reveal the possibility for developing low-power, high-performance integrated circuits for high-temperature operations.

Mechanoelectric effects in healthy cardiac function and under Left Bundle Branch Block pathology

Mechanoelectric feedback (MEF) in the heart operates through several mechanisms which serve to regulate cardiac function. Stretch activated channels (SACs) in the myocyte membrane open in response to cell lengthening, while tension generation depends on stretch, shortening velocity, and calcium concentration. How all of these mechanisms interact and their effect on cardiac output is still not fully understood. We sought to gauge the acute importance of the different MEF mechanisms on heart function.An electromechanical computer model of a dog heart was constructed, using a biventricular geometry of 500K tetrahedral elements. To describe cellular behavior, we used a detailed ionic model to which a SAC model and an active tension model, dependent on stretch and shortening velocity and with calcium sensitivity, were added. Ventricular inflow and outflow were connected to the CircAdapt model of cardiovascular circulation. Pressure–volume loops and activation times were used for model validation.Simulations showed that SACs did not affect acute mechanical response, although if their trigger level was decreased sufficiently, they could cause premature excitations. The stretch dependence of tension had a modest effect in reducing the maximum stretch, and stroke volume, while shortening velocity had a much bigger effect on both. MEF served to reduce the heterogeneity in stretch while increasing tension heterogeneity. In the context of left bundle branch block, a decreased SAC trigger level could restore cardiac output by reducing the maximal stretch when compared to cardiac resynchronization therapy. MEF is an important aspect of cardiac function and could potentially mitigate activation problems.

Designing a virtual reality programming environment for quantum computers

AbstractQuantum computation based on quantum physics is spreading rapidly with many interdisciplinary studies from machine learning to genetics. After the unveiling of real quantum computers, this process has been rising almost exponentially. We are about to experience an effect with quantum computers similar to the effect created by the process from the first electromechanical computers to very large‐scale integrated circuit computers. In the programming of quantum computers, we are in a similar place to programming classical computers at an early stage. There are various models in quantum computing, and the most widely used model is quantum gates. Therefore, an easy and practical understanding of the behavior of the gates used in the programming of quantum computers is of great importance. To realize this process, a virtual reality (VR)‐based teaching platform of quantum computer programming called QU‐VR Education Tool was designed by using Unity 3D VR. In the creation of this design, IBM's so‐called Quantum Composer platform and Microsoft Quantum Katas were taken as a reference. In this study, the design process and usage of a novel VR‐based platform are presented in detail.

Development of a multiscale electromechanical computer model from cell to hemodynamics

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): CVON eDETECT 2015-12 Background Patients with genetic cardiomyopathies mostly remain asymptomatic until the occurrence of life-threatening arrhythmias and sudden cardiac death. The responsible pro-arrhythmic mechanisms, as well as the indicators for pro-arrhythmia, often remain unclear. Current research approaches are commonly based on experimental animal models or clinical data obtained from mutation carriers. The translation (and bridging) of results obtained from experimental models to humans and scale integration of these findings remains challenging. As a consequence, clinical relevance is often disputed. In light of these challenges, computer modelling shows strong potential for its ability to capture the complex dynamics of the cardiovascular system across different scales. Purpose We therefore aim to develop a multiscale electromechanical computer model coupling electrophysiology, sarcomere dynamics (contractility), whole-heart function and hemodynamics to investigate mechanisms (resulting from genetic predisposition to cardiomyopathy) of arrhythmogenicity and cardiac dysfunction in these patients. Methods We coupled our previously published model of cellular electromechanics to the CircAdapt computer model of the heart and circulation. Electromechanical coupling was performed through the amount of calcium bound to troponin (as described in the cellular model). The same electrophysiological properties were assumed in all cardiac walls. Diffusion of calcium from the sarcolemmal space to the membrane was described phenomenologically through a resistance model. Results Simulated hemodynamics properties were in range with control values with LVEDV = 110.8mL, LVESV = 38.7mL, RVEDV = 99.2mL, mLAP = 10.2mmHg, mRAP = 4.0mmHg. At the cellular level, sarcolemmal calcium transients showed the effect of mechanical change as illustrated by the bump in CaT. This effect was attenuated at the membrane due to the effect of diffusion. Alterations in the functionality of molecular entities underlying calcium homeostasis recapitulated cellular experimental findings as expected illustrated by implementing changes in adrenergic signaling. Conclusions We have established a new multiscale electromechanical computer model describing electrophysiology, sarcomere mechanics and hemodynamics. The model simulates normal values in the control situation. Current work focusses on parameter sensitivity analysis and validation. Feeding this new model with experimentally obtained data from patient-specific models (ranging from individual cells to e.g. transgenic mouse models based on relevant mutations) therefore has potential to bridge the gap between pathogenic experimental models and patient data. This will add to the understanding of underlying mechanisms responsible for disease onset and progression, and furthermore could develop into a tool to identify patients/mutation carriers at risk for severe disease outcome. Abstract Figure.

Optically Detecting Acoustic Oscillations at the Nanoscale: Exploring Techniques Suitable for Studying Elastic Wave Propagation

Nanoacoustics is the study of acoustic wave propagation on a submicron scale. Research in this area is motivated by fundamental [1] and technological interests [2]. On the fundamental side, nanoscale objects can provide information about the impact of size, geometry, and surface conditions on elastic properties, elastic energy dissipation, and the validity of continuum mechanics models close to the atomic scale. On the technological side, high-frequency (MHz-THz) nanomechanical oscillators and nanoelectromechanical systems are promising tools for electromechanical computers and information storage, sensors for ultraweak chemicals and biological agents and ultralow forces and masses, radio frequency mobile phone f ilters, and artificial brains for self-aware autonomous vehicles. Furthermore, acoustic microscopy techniques [3]-[6] that rely on elastic waves with nanoscale wavelengths have great potential for materials characterization, failure analysis, and nondestructive imaging of 3D integrated structures with nanoscale scale spatial resolution. Surface acoustic waves (SAWs), which propagate in the near surface of a material with mechanical oscillations confined to a fraction of their wavelength from the surface, have nanoscale wavelengths at frequencies in the hundreds-of-GHz range. The nanoscale confinement of these elastic waves can facilitate studies of ultrasonic properties of individual grain boundaries in nanocrystalline materials [7], applicable to material fracture and nanoscale thermal transport [8].

Cascadable microelectromechanical resonator logic gate

Micro/nano-electromechanical resonator-based logic elements have emerged recently as an attractive potential alternative to semiconductor electronics. The next step for this technology platform to make it into practical applications and to build complex computing operations beyond the fundamental logic gates is to develop cascadable logic units. Such units should produce outputs that can be used as inputs for the next logic units. Despite the recent developments in electromechanical computing, this requirement has remained elusive. Here, we demonstrate for the first time a conceptual framework for cascadable logic units. Cascadability is experimentally demonstrated through two case studies; one by cascading two OR logic gates. The other case is the universal NOR logic gate realized by cascading an OR and a NOT gate. The logic operations are performed by on-demand activation and deactivation of the second mode of vibration of a clamped-clamped microbeam resonator. We show that the demonstrated approach significantly lowers the complexity and number of microresonator-based logic functions compared to the CMOS-based counterparts, which improves energy efficiency. This can potentially lead toward the realization of a novel technology platform for an alternative computing paradigm.

Scalable Manufacturing of Nanogaps.

The ability to manufacture a nanogap in between two electrodes has proven a powerful catalyst for scientific discoveries in nanoscience and molecular electronics. A wide range of bottom-up and top-down methodologies are now available to fabricate nanogaps that are less than 10 nm wide. However, most available techniques involve time-consuming serial processes that are not compatible with large-scale manufacturing of nanogap devices. The scalable manufacturing of sub-10 nm gaps remains a great technological challenge that currently hinders both experimental nanoscience and the prospects for commercial exploitation of nanogap devices. Here, available nanogap fabrication methodologies are reviewed and a detailed comparison of their merits is provided, with special focus on large-scale and reproducible manufacturing of nanogaps. The most promising approaches that could achieve a breakthrough in research and commercial applications are identified. Emerging scalable nanogap manufacturing methodologies will ultimately enable applications with high scientific and societal impact, including high-speed whole genome sequencing, electromechanical computing, and molecular electronics using nanogap electrodes.

Trailblazers in Electromechanical Computing [Historical

Over the last six decades, electronic computing has been thoroughly integrated into the field of science and technology to become a fundamental tool for study, research, and design. Developing into vacuum tube, transistor, integrated circuit, and microprocessor technologies, electronics has boosted an amazing growth in computing power [1]. The commissioning in 2016 of the all-Chinese Sunway TaihuLight with a computing power of 93 PFLOPS (10¹⁵ floating point operations per second), two and a half times larger than the previous top world supercomputer, the Chinese Tianhe-2 of 2013 powered with Intel processors, suggests that the evolution is still far from saturation. It is intriguing to wonder what automatic computing was like before electronics enabled this boost in computing power. Indeed, the search for mechanical tools aimed at relieving the burden of computing reaches far back in the past, at least to ancient times when the abacus was built. However, with electricity this possibility took a major leap forward.

Computation of Magnetic Forces Using Degenerated Air-Gap Element

This paper presents an efficient method to calculate the magnetic forces on bodies in contact. The forces are computed through the local application of the virtual work principle on degenerated air-gap elements. The results from this method are compared with those from other software and validated with measurements on a permanent magnet setup. Not only is this technique very accurate, but it also reduces the computational burden related to the problematic meshing of thin layers. The implementation of this method in an open source finite element software having facilities for higher order elements and parallel computation unlocks a cost effective and effectual platform for an electromechanical computation of electromechanical devices and magnetic materials.

Towards electromechanical computation: An alternative approach to realize complex logic circuits

Electromechanical computing based on micro/nano resonators has recently attracted significant attention. However, full implementation of this technology has been hindered by the difficulty in realizing complex logic circuits. We report here an alternative approach to realize complex logic circuits based on multiple MEMS resonators. As case studies, we report the construction of a single-bit binary comparator, a single-bit 4-to-2 encoder, and parallel XOR/XNOR and AND/NOT logic gates. Toward this, several microresonators are electrically connected and their resonance frequencies are tuned through an electrothermal modulation scheme. The microresonators operating in the linear regime do not require large excitation forces, and work at room temperature and at modest air pressure. This study demonstrates that by reconfiguring the same basic building block, tunable resonator, several essential complex logic functions can be achieved.

Частотно-токовая система релейно-векторного управления асинхронным электроприводом механизма передвижения мостового крана

This paper reports the variant for the advancement of the functional circuit and algorithms to control a bridge crane travels with the correction of misalignment and transverse displacement on basis of the use of new systems of a nonsynchronous electric drive with frequency control. It is offered to use a simple and reliable frequency – current with an autonomous inverter of current and a relayvector algorithm of control. A functional circuit of the system of frequen-cy-current control for the mechanism of a bridge crane travel with the correction of misalignment and transverse displacement. To analyze a crane position there are used differential values obtained by means of the indication difference in contactless sensors measuring a distance from the preset crane points to rails on the opposite supports. The procedure for the computation of control system parameters is stated. For the check of created functional circuits and algorithms of control there is used a complex electromechanical computer model of a bridge crane with a high degree of detailed elaboration (a virtual prototype of a bridge crane). The modeling results of are shown. The shown frequency – current system of control with the correction of misalignment and transverse displacement allows the decrease of threshold differential valuations and the increase of speed and accuracy of regulation

Electromechanical Computing at 500°C with Silicon Carbide

Logic circuits capable of operating at high temperatures can alleviate expensive heat-sinking and thermal-management requirements of modern electronics and are enabling for advanced propulsion systems. Replacing existing complementary metal-oxide semiconductor field-effect transistors with silicon carbide (SiC) nanoelectromechanical system (NEMS) switches is a promising approach for low-power, high-performance logic operation at temperatures higher than 300 degrees C, beyond the capability of conventional silicon technology. These switches are capable of achieving virtually zero off-state current, microwave operating frequencies, radiation hardness, and nanoscale dimensions. Here, we report a microfabricated electromechanical inverter with SiC complementary NEMS switches capable of operating at 500 degrees C with ultralow leakage current.

Dielectric elastomer switches for smart artificial muscles

Some of the most exciting possibilities for dielectric elastomer artificial muscles consist of biologically inspired networks of smart actuators working towards common goals. However, the creation of these networks will only be realised once intelligence and feedback can be fully distributed throughout an artificial muscle device. Here we show that dielectric elastomer artificial muscles can be built with intrinsic sensor, control, and driver circuitry, bringing them closer in capability to their natural analogues. This was achieved by exploiting the piezoresistive behaviour of the actuator’s highly compliant electrodes using what we have called the dielectric elastomer switch. We developed suitable switching material using carbon loaded silicone grease and experimentally demonstrated the primitives required for self-sensing actuators and digital computation, namely compliant electromechanical NAND gates and oscillator circuits. We anticipate that dielectric elastomer switches will reduce the need for bulky and rigid external circuitry as well as provide the simple distributed intelligence required for soft, biologically inspired networks of actuators. Examples include many-degree-of-freedom robotic hearts, intestines, and manipulators; wearable assistive devices; smart sensor skins and fabrics; and ultimately new types of artificial muscle embedded, electromechanical computers.

Electrical Engineering Hall of Fame: Vannevar Bush

In 1943, the American Institute of Electrical Engineers (AIEE) selected Vannevar Bush the recipient of the Edison Medal. He was honored for his role in "the development of new applications of mathematics to engineering problems, and for his eminent service to the nation in guiding the war research program." He spent most of his professional career as an electrical engineering educator and administrator and was a leader in the development of electromechanical computers. His active role in organizing and directing large-scale research and development projects during World War II made him one of the most influential electrical engineers of the twentieth century.

On Frictional Mechanical Systems and Their Computational Power

In this paper we define a class of mechanical systems consisting of rigid objects (defined by linear or quadratic surface patches) connected by frictional contact linkages between surfaces. (This class of mechanisms is similar to the analytical engine developed by Babbage in the 1800s, except that we assume frictional surfaces instead of toothed gears.) We prove that a universal Turing Machine (TM) can be simulated by a (universal) frictional mechanical system in this class consisting of a constant number of parts. Our universal frictional mechanical system has the property that it can reach a distinguished final configuration through a sequence of legal movements if and only if the universal TM accepts the input string encoded by its initial configuration. There are two implications from this result. First, the robotic mover's problem is undecidable when there are frictional linkages. Second, a mechanical computer can be constructed that has the computational power of any conventional electronic computer and yet has only a constant number of mechanical parts. Previous constructions for mechanical computing devices (such as Babbage's analytical engine) either provided no general construction for finite state control or the control was provided by electronic devices (as was common in electromechanical computers such as Mark I subsequent to Turing's result). Our result seems to be the first to provide a general proof of the simulation of a universal TM via a purely mechanical mechanism. In addition, we discuss the universal frictional mechanical system in the context of an error model that allows an error up to $\epsilon$ in each mechanical operation. We first show that, for a universal TM M, a frictional mechanical system in this $\epsilon$-error model can be constructed such that, given any space bound S, the system can simulate the computation of M on any input string $\omega$ if M decides $\omega$ in space bound S, provided that $\epsilon < 2^{-cS}$ for some constant c. We also show that, for any universal TM M and space bound S, there exists a frictional mechanical system in the $\epsilon$-error model with $\epsilon = \Omega(1)$; it has O(S) parts and can simulate M on any input $\omega$ that M decides in space bound S.

Computer: A History of the Information Machine (review)

Reviewed by: Computer: A History of the Information Machine * Robert W. Seidel (bio) Computer: A History of the Information Machine. By Martin Campbell-Kelly and William Asprey. New York: Basic Books, 1996. Pp. ix+342; illustrations, notes, bibliography, index. $28. Computer is a readable and comprehensive history intended to acquaint novices with a growing historical literature as well as to provide an overview of that history from Charles Babbage through Bill Gates. The authors are well-known contributors to that literature. They have gone beyond it, however, in their interpretation, adding insights that can arise only from a synthetic view of the origins, development, and use of the computer. The treatment is divided into computing before computers, the era of the mainframe computer, and the origins of the personal computer and the Internet. The mainframe is given the lion’s share of attention, which reasonably reflects the amount of historical attention devoted to it if not the popular conception of its importance. The prelude to the mainframe is concisely set forward in the first quarter of the book. Here Martin Campbell-Kelly and William Asprey focus on the technological opportunities and economic and scientific needs of industrializing England and France in the early nineteenth century. In particular, the coupling of scientists’ needs for better means of calculating tables and banks’ needs for better means of exchanging checks inspired Babbage’s attempts to mechanize these processes in his difference engine. The subsequent development of transportation and communication provided other incentives to mechanize information processing, but for Babbage the solution of these problems remained a dream. The American analog to the English demand for mechanized processing of information was the U.S. census, for although the former colony lagged behind Britain in industrialization, it was more advanced in social statistics. Herman Hollerith succeeded where Babbage had failed in providing a solution to the increasing difficulty of keeping track of an exploding population. Americans also benefited from their backwardness by taking advantage of new office machines that became available after the Civil War. Besides the economic advantages of backwardness, which Alexander Gerschenkron explored more thoroughly, both the importance of labor-saving devices in the United States as described by H. J. Habakkuk and the production technologies of the American system of manufactures, which [End Page 820] David Hounshell and others have analyzed, played a role in the rapid adoption of machines to process information. Here the authors miss an opportunity to relate their subject to broader trends in economic history and the history of technology. The growth of the business machine industry, told here in terms of government needs (the census, Social Security) and entrepreneurs’ responses (NCR’s Patterson, IBM’s Watson) is part of a much larger pattern of industrial development and economic growth. The heart of the book is the oft-told story of the development of the modern computer, which is here presented as the fulfillment of Babbage’s dream, not in Cambridge, England, but in Cambridge, Massachusetts, where Vannevar Bush and Howard Aiken perfected the electromechanical computer. Bush’s differential analyzer was immediately adopted by the British for scientific computation, whereas Aiken’s Mark I “had a short heyday before being eclipsed by electronic machines which operated much faster because they had no moving parts. . . . Not only was the Harvard Mark I a technological dead end, it did not even do anything very useful in the fifteen years that it ran” (p. 75). The rapid obsolescence of the electromechanical computer had everything to do with World War II, which provided, in computing as in so many other fields, unprecedented sums of money from America’s military establishment for high-technology weapons and tools of war, such as machines to calculate the trajectory of artillery shells. The postwar story of mainframe computing shows how the legacy of this wartime development was extended by IBM and the “seven dwarves,” a mix of business machine, electronic, and entrepreneurial firms funded by the cold war development of the SAGE air-defense system and DARPA’s contributions to computer technology. Although this is a familiar story, it is told effectively here, and without sparing the authors’ judgments of the historical forces that favored IBM...

From Computor to Electrical Engineer: The Remarkable Career of Edith Clarke

Edith Clarke's electrical engineering career had as a central theme the development and dissemination of mathematical methods that served to simplify and reduce the time spent on laborious calculations in solving problems encountered in the design and operation of large electrical power systems. As an engineer with the General Electric Company from the early 1920's to 1945, she worked during a time when power system analysis was evolving from being labor intensive to being machine intensive, with much of the labor of problem solving being shifted from human computors, often women, to electromechanical computers, such as the network analyzer and differential analyzer. This trend culminated in the development of electronic computers beginning with the ENIAC that was completed during the same year that she retired from GE. As a woman who worked in an environment traditionally dominated by men, she demonstrated that women could perform engineering analysis at least as well as men if given the opportunity. Her achievements provided an inspiring example for the next generation of women with aspirations to seek a career in electrical engineering.

Instrumentation for Simplified Commingling and Well-Testing Operations

KITE, GEORGE, BLACK, SIVALLS and BRYSON, INC., TULSA, OKLA. Abstract This paper discusses the theory, operation and practical application of a low-cost, field-proven instrumentation system which saves money and greatly simplifies lease-commingling and well-testing operations by providing an accurate, direct digital readout of the volume of net clean oil in oil-water streams containing up to 100 per cent water. Introduction Lease-commingling and well-testing operations usually require a measurement of the amount of "net clean oil" in an emulsion stream produced by a well or group of wells. Conventional methods of net oil metering require physical separation or treating and subsequent metering of oil and water volumes. Various arrangements of three-phase separators, gas-fired emulsion treaters, fluid meters and samplers are in wide use but are often unnecessarily expensive and complicated; frequently they leave much to be desired insofar as accuracy, operator convenience and adaptability to automation are concerned. The instrumentation system discussed automatically and continuously meters and monitors an oil-water stream containing pure oil, pure water, emulsion, or any combination thereof, and, without requiring physical treating or separation, provides an accurate digital readout of net clean oil volume, directly in barrels. No calculations, conversion factors, or interpretations are required; data are presented instantly, continuously and cumulatively in the most usable form. In addition, electrical digital signals for remote counting and an electrical analog signal for remote percentage water indication or recording are available at the computer terminal block. Description of Equipment The system uses an ordinary positive-displacement fluid meter, a wide-range electronic capacitance-measuring instrument, and an electro-mechanical computer. The PD meter measures total fluid volume and supplies a rotational, mechanical input to the computer. The capacitance instrument electronically determines the instantaneous percentage of water in the fluid stream. The computer subtracts the water volume from the total fluid volume and provides an output of the integrated volume of net clean oil. Fig. 1-A shows a typical skid-mounted net oil measuring assembly, consisting of a fluid strainer, a PD meter, a capacitance probe, the computer assembly and a diaphragm-operated fluid dump valve. This skid assembly would be installed downstream of a conventional fluid-gas separator, which is required only to prevent gas from damaging the PD meter. In operation all separator liquids would be discharged from the separator outlet through the skid assembly. Liquid dumping would be controlled by the pneumatic, snap-acting level control on the separator and the diaphragm-operated dump valve on the skid assembly. Two counters in the computer panel would then provide a direct readout of barrels of total fluid and barrels of net clean oil. JPT P. 732ˆ

Minimum Time Control of Second Order Pulse-Width-Modulated Sampled-Data Systems

This paper treats the minimal time control problem for two second order pulse-width-modulated sampled-data systems, one with a double integrator type plant and one with a plant described by an integral and a time constant. Such plants are encountered in systems with hydraulic components. It is shown rigorously that for minimal time control the phase plane can be divided into two regions: a striplike region around the optimal switching trajectory for a continuous relay system with the same plants, in which the pulse width must be adjusted for optimal action; and the rest of the phase plane in which an optimal p.w.m. system of the type described behaves like a continuous optimal relay system, the pulse duration being equal to the sampling period. A brief description of an electromechanical computer capable of implementing minimal time control for these systems is also given.