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Full-Text Articles in Engineering

Aeroelastic Energy Harvesting Using A Nonlinear Electromagnetic Oscillator, Katherine Bender, Ndungu Muturi, Alex Spies, Christopher Lee Apr 2013

Aeroelastic Energy Harvesting Using A Nonlinear Electromagnetic Oscillator, Katherine Bender, Ndungu Muturi, Alex Spies, Christopher Lee

Christopher Lee

Results are presented from the design, fabrication and testing of an electromagnetic-inductor device to convert aeroelastic-induced oscillations of an airfoil into electricity. The energy harvester consists of three magnets configured such that the force-displacement relationship can be described by a fifth-degree polynomial. the integration of the harvester into a two-degree-of-freedom, pitch/plunge airfoil system introduces nonlinear stiffness into the plunge direction. This nonlinearity gives rise to limit cycle oscillations which, in turn, are converted to electric power by the harvester. Experimental measurements from wind tunnel tests are compared to predictions of limit cycle response and resulting power generation using a two-degree-of-freedom …


Sensor Data As A Service - A Federated Platform For Mobile Data-Centric Service Development And Sharing, Jia Zhang, Robert Iannucci, Mark Hennessy, Kaushik Gopal, Sean Xiao, Sumeet Kumar, David Pfeffer, Basmah Aljedia, Yuan Ren, Martin Griss, Steven Rosenberg, Jordan Cao, Anthony Rowe Dec 2012

Sensor Data As A Service - A Federated Platform For Mobile Data-Centric Service Development And Sharing, Jia Zhang, Robert Iannucci, Mark Hennessy, Kaushik Gopal, Sean Xiao, Sumeet Kumar, David Pfeffer, Basmah Aljedia, Yuan Ren, Martin Griss, Steven Rosenberg, Jordan Cao, Anthony Rowe

Robert A Iannucci

No abstract provided.


On The Potential Uses Of Static Offsets Derived From Low-Cost Community Instruments And Crowd-Sourcing For Earthquake Monitoring And Rapid Response, Sarah Minson, Benjamin Brooks, Jessica Murray, Robert Iannucci Dec 2012

On The Potential Uses Of Static Offsets Derived From Low-Cost Community Instruments And Crowd-Sourcing For Earthquake Monitoring And Rapid Response, Sarah Minson, Benjamin Brooks, Jessica Murray, Robert Iannucci

Robert A Iannucci

No abstract provided.


A Simple Low-Voltage Cascode Current Mirror With Enhanced Dynamic Performance, Bradley Minch Oct 2012

A Simple Low-Voltage Cascode Current Mirror With Enhanced Dynamic Performance, Bradley Minch

Bradley Minch

In this paper, we present a simple low-voltage MOS cascode current mirror featuring a step response and an output voltage swing comparable to those of a simple mirror and and output resistance comparable to that of a stacked mirror. The proposed mirror operates with an input voltage of Vdiode+VDSsat and can operate on a minimum supply of Vdiode + 2VDSsat. We validate the proposed mirror with a combination of simulated and measured results from a circuit prototyped from transistor arrays fabricated in a 0.5-μm CMOS process through MOSIS.


Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti Jul 2012

Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies. Power transfer using magnetically coupled series resonators is maximized when the load presented to the sender is matched to the series impedance of the source. This determines an optimal separation distance between the sender and the receiver. However, the maximum power transferred only depends on the losses in the system and is independent of this distance and the resonant frequency. Closed-form expressions describe the power transferred and efficiency for all distances and system values. These expressions are validated with systems operating at 23 kHz, 40 kHz …


Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe Jul 2012

Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies and enable applications that are currently unimaginable because of power constraints. Magnetic induction has been extensively used for wireless power transfer, but its efficiency depends on magnetic coupling that decays as the inverse cube of distance. At long enough distances, the magnetic coupling is weak enough that the effect of the receiver coil on the sender coil can be neglected. In this weakly coupled limit, series resonance in both the sender and the receiver increases the power transfer. Compared to magnetic induction, the power transfer increases …


Power Mems And Microengines, Alan Epstein, Stephen Senturia, G. Ananthasuresh, Arturo Ayon, Kenneth Breuer, Kuo-Shen Chen, Fredric Ehrich, Gautam Gauba, Reza Ghodssi, C. Groshenry, Stuart Jacobson, Jeffrey Lang, Chuang-Chia Lin, Amit Mehra, José Oscar Mur-Miranda, Steve Nagle, D. Orr, Ed Piekos, Martin Schmidt, Gregory Shirley, Mark Spearing, Choon Tan, Sheng-Yang Tzeng, Ian Waitz Jul 2012

Power Mems And Microengines, Alan Epstein, Stephen Senturia, G. Ananthasuresh, Arturo Ayon, Kenneth Breuer, Kuo-Shen Chen, Fredric Ehrich, Gautam Gauba, Reza Ghodssi, C. Groshenry, Stuart Jacobson, Jeffrey Lang, Chuang-Chia Lin, Amit Mehra, José Oscar Mur-Miranda, Steve Nagle, D. Orr, Ed Piekos, Martin Schmidt, Gregory Shirley, Mark Spearing, Choon Tan, Sheng-Yang Tzeng, Ian Waitz

José Oscar Mur-Miranda

MIT is developing a MEMS-based gas turbine generator. Based on high speed rotating machinery, this 1 cm diameter by 3 mm thick SiC heat engine is designed to produce 10-20 W of electric power while consuming 10 grams/hr of H2. Later versions may produce up to 100 W using hydrocarbon fuels. The combustor is now operating and an 80 W micro-turbine has been fabricated and is being tested. This engine can be considered the first of a new class of MEMS device, power MEMS, which are heat engines operating at power densities similar to those of the best large scale …


The Search For Design In Electrical Engineering Education, David Kerns, Sherra Kerns, Mark Somerville, Gill Pratt, Jill Crisman Jul 2012

The Search For Design In Electrical Engineering Education, David Kerns, Sherra Kerns, Mark Somerville, Gill Pratt, Jill Crisman

Mark Somerville

The importance of "design" in engineering education is well established and a cornerstone of most new engineering curricula as well as accreditation criteria Electrical and computer engineering (ECE) programs view many elements of design in ways similar to other engineering disciplines. However, in some respects other disciplines within engineering, such as Mechanical Engineering (ME), view design in broader terms, and perhaps gain value that electrical and computer engineering educators may miss. This paper describes how design is typically viewed in ECE programs, bow it's viewed in other engineering areas, particularly ME, and suggests some new possibilities for enhancing design education …


Floating-Gate Devices: They Are Not Just For Digital Memories Anymore, Paul Hasler, Bradley Minch, Chris Diorio Jul 2012

Floating-Gate Devices: They Are Not Just For Digital Memories Anymore, Paul Hasler, Bradley Minch, Chris Diorio

Bradley Minch

Since the first reported floating-gate structure in 1967, floating-gate transistors have been used widely to store digital information for long periods in structures such as EPROMs and EEPROMs. Recently floating-gate devices have found applications as analog memories, analog and digital circuit elements, and adaptive processing elements. Floating-gate devices have found commerical applications, e.g. ISD, for long-term non-volatile information storage devices for analog applications. The focus of floating-gate devices has been towards fabrication in standard CMOS processes, as opposed to the specialized processes for fabricating digital non-volatile memories. Floating-gate circuits can be designed at any or all of three levels: analog …


Synthesis Of Multiple-Input Translinear Element Networks, Bradley Minch, Paul Hasler, Chris Diorio Jul 2012

Synthesis Of Multiple-Input Translinear Element Networks, Bradley Minch, Paul Hasler, Chris Diorio

Bradley Minch

We describe two systematic procedures for synthesizing multiple-input translinear element (MITE) networks that produce an output current that is equal to product of a number of input currents, each of which is raised to an arbitrary rational power. By using the first procedure, we obtain a MITE network, called a two-layer network, that is relatively insensitive to mismatch in the MITE weight values. By using the second procedure, we arrive at a MITE network, called a cascade network, that reduces the fan-in required of each MITE. We illustrate each ofthese procedures with an example.


A Floating-Gate Technology For Digital Cmos Processes, Bradley Minch, Paul Hasler Jul 2012

A Floating-Gate Technology For Digital Cmos Processes, Bradley Minch, Paul Hasler

Bradley Minch

We discuss the possibility of developing high-quality floating-gate memories and circuits in digital CMOS technologies that have only one layer of polysilicon. Here, the primary concern is whether or not we can get adequate control-gate linearity from MOS capacitors. We employ two experimental procedures to address this issue and find acceptable floating-gate circuit behaviour with MOS capacitors. First, we simultaneously characterize an MOS capacitor and a linear capacitor; the experimental data show that MOS capacitors behave similarly to linear capacitors over a finite, but usable range. Second, we characterize two typical floating-gateMOS circuit primitives, a floating-gate amplifier and a multiple-input …


Adaptive Circuits Using Pfet Floating-Gate Devices, Paul Hasler, Bradley Minch, Chris Diorio Jul 2012

Adaptive Circuits Using Pfet Floating-Gate Devices, Paul Hasler, Bradley Minch, Chris Diorio

Bradley Minch

In this paper, we describe our floating-gate pFET device, with its many circuit applications and supporting experimental measurements. We developed these devices in standard double-poly CMOS technologies by utilizing many effects inherent in these processes. We add floating-gate charge by electron tunneling, and we remove floating-gate charge by hot-electron injection. With this floating-gate technology, we cannot only build analog EEPROMs, we can also implement adaptation and learning when we consider floating-gate devices to be circuit elements with important time-domain dynamics. We start by discussing non-adaptive properties of floating-gate devices and we present two representative non-adaptive applications. First, we discuss using …


Medic: A Legged Millirobot Utilizing Novel Obstacle Traversal, Nicholas Kohut, Aaron Hoover, Kevin Ma, Stanley Baek, Ronald Fearing Jul 2012

Medic: A Legged Millirobot Utilizing Novel Obstacle Traversal, Nicholas Kohut, Aaron Hoover, Kevin Ma, Stanley Baek, Ronald Fearing

Aaron M. Hoover

This work presents the design, fabrication, capabilities, and obstacle traversal mechanics of MEDIC (MillirobotEnabled Diagnostic of Integrated Circuits), a small legged robot able to overcome a varied array of obstacles. MEDIC features a hull that keeps its body in contact with the ground at all times, and uses only four actuators to move forward, turn, mount obstacles, and move in reverse. The chassis is fabricated using a Smart Composite Microstructures (SCM) approach and the robot is actuated by coiled Shape Memory Alloy (SMA). MEDIC also features a camera which will be useful for navigation in the future.


A Rapidly Prototyped 2-Axis Positioning Stage For Microassembly Using Large Displacement Compliant Mechanisms, Aaron Hoover, Srinath Avadhanula, Richard Groff, Ronald Fearing Jul 2012

A Rapidly Prototyped 2-Axis Positioning Stage For Microassembly Using Large Displacement Compliant Mechanisms, Aaron Hoover, Srinath Avadhanula, Richard Groff, Ronald Fearing

Aaron M. Hoover

Compliant mechanisms provide an attractive alternative to conventional rigid mechanisms in the design of ultra low-cost precision positioning systems. The desirable performance characteristics of these mechanisms including freedom from backlash, long life, light weight, and ease of fabrication/assembly make them an ideal solution to the problem of inexpensive precision positioning for microassembly. This paper presents a design for a 2 axis precision positioning system which makes use of large displacement compliant mechanisms, a room temperature and pressure molding fabrication process, commodity hardware, and a piecewise linear interpolation compensation scheme to achieve positioning performance suitable for automated assembly of sub-centimeter robotic …


Perimeter Patrol On Autonomous Surface Vehicles Using Marine Radar, Elena Oleynikova, Nicole Lee, Andrew Barry, Joseph Holler, David Barrett Jul 2012

Perimeter Patrol On Autonomous Surface Vehicles Using Marine Radar, Elena Oleynikova, Nicole Lee, Andrew Barry, Joseph Holler, David Barrett

David Barrett

Perimeter patrol enhances the utility of autonomous surface vehicles (ASVs) by enabling many security and scientific missions, including harbor protection, water sampling, and geological survey. We present a novel approach to perimeter patrol that uses only two sensors: commercial off-the-shelf available marine radar and the heading information from a GPS. Our algorithm performs computer vision morphological operations on the radarimage to find a suitable path around shore and choose an appropriate next waypoint. Our method has proved robust to a variety of field conditions, allowing us to demonstrate the autonomous navigation of a 3.5 km perimeter lake.


Optimal Synthesis Of Mite Translinear Loops, Shyam Subramanian, David Anderson, Paul Hasler, Bradley Minch Jul 2012

Optimal Synthesis Of Mite Translinear Loops, Shyam Subramanian, David Anderson, Paul Hasler, Bradley Minch

Bradley Minch

A procedure for synthesizing multiple-input translinear element (MITE) networks that implement a given system of translinear-loop equations (STLE) is presented. The minimum number of MITEs required for implementing the STLE, which is equal to the number of current variables in the STLE, is attained. The number of input gates ofthe MITEs is minimal amongst those MITE networks that satisfy the STLE and have the minimum number of MITEs. The synthesized MITE networks have a unique operating point and, in many cases, the network is guaranteed to be stable in a particular sense. This synthesis procedure exploits the relationship between MITEproduct-of-power-law …


Synthesis Of Translinear Analog Signal Processing Systems, Eric Mcdonald, Bradley Minch Jul 2012

Synthesis Of Translinear Analog Signal Processing Systems, Eric Mcdonald, Bradley Minch

Bradley Minch

In this paper, we describe a structured methodology for synthesizing translinear analog signal-processing systems from high-level descriptions in the time domain. The circuits are implemented from elements called multiple-input translinear elements (MITEs). We illustrate the synthesis methodology with the simple example ofan RMS-DC converter.


Programmable Multiple Input Translinear Elements, Haw-Jing Jo, Guillermo Serrano, Paul Hasler, David Anderson, Bradley Minch Jul 2012

Programmable Multiple Input Translinear Elements, Haw-Jing Jo, Guillermo Serrano, Paul Hasler, David Anderson, Bradley Minch

Bradley Minch

Large networks composed of multiple input translinear elements (MITEs) have been typically limited by the mismatches between individual MITEs. This paper presents the methodology that allows for such systems to be feasible through the application of floating-gate programming techniques. We introduce designs for a programmable MITE, and demonstrate the ability to systematically reduce offsets through accurate programming of example circuits.


A Low-Voltage Mos Cascode Current Mirror For All Current Levels, Bradley Minch Jul 2012

A Low-Voltage Mos Cascode Current Mirror For All Current Levels, Bradley Minch

Bradley Minch

In this paper, we describe a simple low-voltage MOS cascode current mirror that functions well at all current levels, ranging from weak inversion to strong inversion. The circuit features a wide output voltage swing and requires an input voltage of approximately one diode drop plus a saturation voltage. We present experimental results from a version of the current mirror that was fabricated in a 0.5 μm CMOS process along with a comparison with several other current mirrors with respect both to required input voltage and to output compliance voltage.


A Fully Programmable Log-Domain Bandpass Filter Using Multiple-Input Translinear Elements, Ravi Chawla, Haw-Jing Lo, Arindam Basu, Paul Hasler, Bradley Minch Jul 2012

A Fully Programmable Log-Domain Bandpass Filter Using Multiple-Input Translinear Elements, Ravi Chawla, Haw-Jing Lo, Arindam Basu, Paul Hasler, Bradley Minch

Bradley Minch

In this paper a second order log-domain bandpass filter using multiple input translinear elements (MITEs) operating at a 3V supply. We enhance the capabilities of the filter by utilizing programmable MITE structures as well as programmable current sources, which are covered in this paper. The synthesized bandpass filter is implemented and fabricated using these programmable translinear devices (MITEs). Experimental results are shown from circuit fabricated on a 0.5μm nwell CMOS process available through MOSIS.


Synthesis Of Dynamic Multiple-Input Translinear Element Networks, Bradley Minch Jul 2012

Synthesis Of Dynamic Multiple-Input Translinear Element Networks, Bradley Minch

Bradley Minch

In this paper, the author discusses an approach to the synthesis of dynamic translinear circuits built from multiple-input translation elements (MITEs). In this method, we realize separately the basic static nonlinearities and dynamic signal-processing functions that when cascaded together, form the system that one wishes to construct. The circuit is then simplified systematically through local transformations that do not alter the behavior of the system. The author illustrates the method by synthesizing a simple nonlinear dynamical system, an RMS-DC converter.


Adaptive Translinear Analog Signal Processing: A Prospectus, Eric Mcdonald, Kofi Odame, Bradley Minch Jul 2012

Adaptive Translinear Analog Signal Processing: A Prospectus, Eric Mcdonald, Kofi Odame, Bradley Minch

Bradley Minch

We have devised a systematic method of transforming high-level time-domain descriptions of linear and nonlinear adaptive signal-processing algorithms into compact, continuous-time analog circuitry using basic units called multiple-input translinear elements (MITEs). In this paper, we describe the current state of the art and illustrate the method with an example of an analog phase-locked loop (PLL).


Synthesis Of A Translinear Analog Adaptive Filter, Eric Mcdonald, Bradley Minch Jul 2012

Synthesis Of A Translinear Analog Adaptive Filter, Eric Mcdonald, Bradley Minch

Bradley Minch

In this paper, we present a methodology for synthesizing analog systems using a class of circuits called dynamic translinear circuits. We illustrate this method by synthesizing part of a Least-Mean-Squares (LMS) adaptation algorithm used in an analog adaptive filter. We present preliminary experimental results from a chip fabricated ina 0.5-μm double-poly CMOS process.


Inverting The Bipolar Differential Pair For Low-Voltage Applications, Bradley Minch Jul 2012

Inverting The Bipolar Differential Pair For Low-Voltage Applications, Bradley Minch

Bradley Minch

In this paper, the author presents a new bipolar differential transconductor that functions just like an emitter-degenerated differential pair, except for the following: it operates on a low power supply; it has a rail-to-rail common-mode input-voltage range; permits a wide output-voltage swing; has a transconductance gain that is nearly constant with the common-mode input voltage; and requires only n-p-n transistors in the signal path. We describe intuitively how the circuit functions and provide DC measurements from a prototype circuit, breadboarded from a quad TPQ3904 and a thick-film resistor array demonstrating proper operation on a single-ended 1.2-V power supply.


Highly Linear, Wide-Dynamic-Range Multiple-Input Translinear Element Networks, Kofi Odame, Eric Mcdonald, Bradley Minch Jul 2012

Highly Linear, Wide-Dynamic-Range Multiple-Input Translinear Element Networks, Kofi Odame, Eric Mcdonald, Bradley Minch

Bradley Minch

In this paper, we propose a modification to the class of circuits known as multiple input translinear element (MITE) networks. Our proposed modification leads to a MITE network that is free from certain nonidealities encountered in previous implementations. Further, the new MITE network described here readily accommodates the use of bipolar junction transistors in the input and output stages, thus implying a significantly wider dynamic range than we can achieve using subthreshold MOSFETs.


Synthesis Of Multiple-Input Translinear Element Log-Domain Filters, Bradley Minch Jul 2012

Synthesis Of Multiple-Input Translinear Element Log-Domain Filters, Bradley Minch

Bradley Minch

I present a simple procedure for synthesizing multiple-input translinear element (MITE) log-domain filters from state-space descriptions. We can obtain such state-space descriptions from a variety of sources, and the procedure that I describe can be utilized regardless of the source of the description. We can often derive such descriptions conveniently from already extant filters that have been previously implemented using a different class of filters. I shall illustrate the synthesis procedure by deriving two simple MITE log-domain filters from single-ended voltage-mode OTA-C filter prototypes-I synthesize both a first-order lowpass filter and a fully tunable second-order lowpass filter.


A Low-Voltage Mos Cascode Bias Circuit For All Current Levels, Bradley Minch Jul 2012

A Low-Voltage Mos Cascode Bias Circuit For All Current Levels, Bradley Minch

Bradley Minch

In this paper, the author describes a simple low-voltage MOS cascode bias circuit that functions well at all current levels, ranging from weak inversion to strong inversion. He describes an approach to defining the onset of saturation that is generally useful from a bias-circuit design viewpoint and explains specifically how it was used in designing the low-voltage cascode bias circuit. The author discusses an efficient strategy for laying out the cell in the full-stacked style. He also presents experimental results from a version of the bias circuit that was fabricated in a 1.2-μm CMOS process.


Multi-Level Simulation Of A Translinear Analog Adaptive Filter, Eric Mcdonald, Bradley Minch Jul 2012

Multi-Level Simulation Of A Translinear Analog Adaptive Filter, Eric Mcdonald, Bradley Minch

Bradley Minch

In this paper, we briefly discuss a methodology for synthesizing analog systems from a high-level behavioral specification using a class of circuits called dynamic translinear circuits. We illustrate this method by synthesizing a Least-Mean-Square (LMS) adaptation algorithm used in an analog adaptive filter. The resulting systems can be simulated at various levels of abstraction during the design phase. As an example, we presentsimulation results from a four-tap analog adaptive filter simulated using Matlab and SPICE.


Analog Vlsi Implementation Of Support Vector Machine Learning And Classification, Sheng-Yu Peng, Bradley Minch, Paul Hasler Jul 2012

Analog Vlsi Implementation Of Support Vector Machine Learning And Classification, Sheng-Yu Peng, Bradley Minch, Paul Hasler

Bradley Minch

We propose an analog VLSI approach to implementing the projection neural networks adapted for the supportvector machine with radial-basis kernel functions, which are realized by a proposed floating-gate bump circuit with the adjustable width. Other proposed circuits include simple current mirrors and log-domain Alters. Neither resistors nor amplifiers are employed. Therefore it is suitable for large-scale neural network implementations. We show the measurement results of the bump circuit and verify the resulting analog signal processing system on the transistor level by using a SPICE simulator. The same approach can also be applied to the support vectorregression. With these analog signal …


A Long-Channel Model For The Asymmetric Double-Gate Mosfet Valid In All Regions Of Operation, Abhishek Kammula, Bradley Minch Jul 2012

A Long-Channel Model For The Asymmetric Double-Gate Mosfet Valid In All Regions Of Operation, Abhishek Kammula, Bradley Minch

Bradley Minch

We present a physically based, continuous analytical model for long-channel double-gate MOSFETs. The model is particularly well suited for implementation in circuit simulators due to the simple expressions for the current andthe continuous nature of the derivatives of the current which improves convergence behavior.