Electrical & Computer Engineering - Infrastructure & Energy/Environmental Technology

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Primary Investigator: Hulya Seferoglu

Energy Efficiency in Cooperating Mobile Devices

Problem Statement and Motivation • Increasing popularity of applications such as video streaming in mobile devices introduces: • Higher demand for throughput; • Strain on cellular links. • Cooperation among mobile devices by exploiting both cellular and local area connections (WiFi, Bluetooth) is promising. • Popularity of applications  exponential increase in data rates. • The energy per delivered bit needs to be reduced in cooperating mobile devices.

Technical Approach • Goal: Develop energy efficient cooperation schemes for mobile devices by taking into account energy consumption cost of mobile devices while maximizing throughput. • Approach: • Develop stochastic network control algorithms that take into account practical requirements of cooperating mobile devices. • Investigate energy consumption cost of mobile devices and its impact on the control algorithms. • Investigate energy storage (battery) levels of mobile devices. • Develop energy efficient stochastic network control algorithms for cooperating mobile devices.

Key Achievements and Future Goals • The PI has published several conference and journal papers in the broader area. • The PI is planning to submit a proposal on this topic.


P.I. Igor Paprotny Funding: new faculty startup, Intel, DOE

Problem Statement and Motivation • • •

Airborne particulate matter (PM) is harmful to our health In particular fine PM smaller than 2.5 µm in diameter (PM2.5) Includes: • Diesel exhaust • Tobacco smoke • Bio-aerosols

• •

Current instruments are too big and expensive to be portable Personal PM2.5 sensor does not exist

Key Achievements and Future Goals

Technical Approach • • •

Use MEMS techniques to create air-microfluidic lab-on-a-chip that measures airborne PM by direct mass deposition Inertial separation (virtual impaction) is used to separate PM2.5 from the rest of the airstream. Thermophoretic precipitation is used to deposit the separated PM2.5 on top of a mass-sensitive film-bulk acoustic resonator (FBAR) The rate of the frequency shift in the FBAR corresponds to the PM2.5 concentration.

• • • •

Demonstrated a microfabricated PM2.5 direct-mass sensor • 5 cm x 2.5 cm x 1 cm in size Sensitivity comparable to large instruments • 1-2 µg/m3 PM2.5 concentration Form factor enables integration into a regular cellphone Future goals: • Improve sensitivity • Measure particle-size distribution • Chemical speciation


P.I. Igor Paprotny Funding: Department of Health and Human Services

Problem Statement and Motivation • • • •

Key Achievements and Future Goals

Technical Approach • • • •

A flat surface placed in a mine environment collects deposited dust Incident light at several wave-lengths is reflected from the deposited layer, and is collected by a photo-detector Microfabricated mass sensors and humidity sensors helps to determine the true explosibility of the deposited layers Connects to a communication backbone to automate the operation of the rock dusting equipment

Excessive build-up of coal dust in underground mines leads to explosion risk Rock-dusting (dispensing of inert lime-stone dust) is used to mitigate the explosion risk • Increasing total incombustible content (TIC) Currently manual sampling of dust in mines to determine TIC and control rock dusting A low-cost reliable automated method is needed

• • •

Verified the viability of using multi-wavelength optical method to detected the layers of deposited dust Created preliminary sensor prototype Future goals: • Determine the dependence of the optical method on humidity content and particle size, as well as the layer thickness • Create a MEMS mass and humidity sensor • Integrate with a communication backbone in the underground mine


Mahshid Amirabadi, Department of Electrical and Computer Engineering

Problem Statement and Motivation •

Key Achievements and Future Goals

Technical Approach •

ac-link universal power converters are new class of power converters with numerous advantages over the existing technologies: • The input and output of these converters may be dc, single phase ac, or multiphase ac. They can be employed in a variety of applications including, but not limited to, photovoltaic power generation and wind power generation systems. • Link current and voltage are alternating and their frequency can be high. This results in compact link and filter elements. • They do not need dc electrolytic capacitors or low frequency transformers. • ac-link Universal power converters provide soft switching. Therefore, the switching losses are negligible and the link frequency may be increased further.

Power Electronics is an integral part of many systems including, but not limited to, renewable energy systems and electric and hybrid electric vehicles. The existing power electronic circuits have some limitations • They are usually bulky. • Their reliability is low and they have a short lifetime. For example, the lifetime of the PV inverters is 5-10 years whereas the life time of a PV module is 25 years. Therefore, PV inverters need to be replaced 2 or 3 times within the lifetime of a PV module. • The low reliability of power converters adds cost to the system. For the long-term success of renewable energy sector we have to increase the reliability of power converters, decrease their size/weight and reduce their cost.

• • • •

ac-link universal power converters are much more compact compared to the existing technologies. They have higher reliability. They are less expensive. Sparse and ultra-sparse ac-link universal power converters have the same principles of the operation but they require fewer switches: • They further decrease the size. • They dramatically increase the reliability. • They are less expensive than the ac-link universal power converters.


Sudip K. Mazumder, ECE Primary Grant Support: NSF, DOE (SECA and I&I), PNNL, CEC, NASA, Ceramatec, Airforce (award pending), TI, Altera

Problem Statement and Motivation •

To achieve reliable interactive power-electronics networks

To design and develop power-management electronics for residential and vehicular applications of renewable/alternate energy sources (e.g., fuel and photovoltaic cells)

To achieve higher power density and realize systems on chip

Key Achievements and Future Goals

Technical Approach •

Stability and Stabilization of Power-Electronics Networks: a) Global stability analysis of stochastic and functional hybrid system b) Stabilization using wireless networked control

Optimal Fuel Cell based Stationary and Vehicular Energy Systems a) Resolving interactions among energy source (such as fuel cells), power electronics, and balance of plant. b) Fuel-cell power-electronics inverter design that simultaneously meet criteria of cost, durability, and energy efficiency

Robust and efficient power devices and smart power ASIC a) High-speed, EMI immune, wide-bandgap power devices b) Integration of low- and high-voltage electronics on the same chip

First, wireless distributed control dc/dc and multiphase converters and three-phase induction motor control

First, zero-ripple, multilevel, energy-efficient fuel cell inverter

First, photonically-triggered power transistor design for power electronics

First, nonlinear VRM controller for next-generation Pentium processors

Comprehensive solid-oxide-fuel-cell (SOFC) spatio-temporal system model


Sudip K. Mazumder, Professor, Electrical and Computer Engineering Department Director, Laboratory for Energy and Switching-Electronics Systems Funding Agencies: NSF, ONR, DOE, AFRL, GeneSiC Semiconductor, APEI

Hybrid SiC optical power device

Optically-switched highfrequency and high-voltage power converter

Problem Statement and Motivation •

To realize a high-gain, high-voltage, and high-temperature opticallyswitched power transistor, which is triggered in a non-latched manner using low power monochromatic photonic source by monolithically integrating an optically-controlled transistor with a high-voltage SiC field-effect transistor.

The scalable device technology can have radical impact for highvoltage and ultra-high-frequency power-electronics/power systems including solar/wind/fuel-cell inverters, energy storage systems, pulsed power, fault current limiting, fly-by-light systems, solid-state transformer, electromagnetic-interference-immune systems.

Key Achievements and Future Goals

Technical Approach •

GaAs-based optically-controlled high-gain superjunction lateral triggering device to enable non-latched and low-cost long-wavelength triggering SiC based high-voltage and high-temperature vertical metal-oxidesemiconductor-field-effect transistor (MOSFET) for power switching at high frequency and high voltage

Optoelectronic integration of the hybrid SiC MOSFET and GaAs based optical triggering device to yield hybrid SiC optical power device

Power converter design and fabrication using the hybrid SiC optical power device and switching characterization of the power converter under high-frequency and high-voltage operation.

• • • • •

World’s first  0.25 MHz wide-bandgap device based opticallyswitched dc/dc converter 6 NSF, ONR, DOE, and AFRL grants 2 U.S. patents received and 1 patent pending 2 journal papers in IEEE Transactions on Power Electronics with an impact factor > 5 Future work involves a) optically controlled very high voltage (> 15 kV) SiC bipolar transistor; b) control of a power-electronic system at device level by dynamic intensity and/or wavelength modulation of the optical power device.


P.L.E. Uslenghi (P.I.), S. Dutt, D. Erricolo, H-.Y. D. Yang, ECE in collaboration with Clemson University, Houston University, Ohio State University, University of Illinois at Urbana-Champaign, University of Michigan Primary Grant Support: AFOSR

Problem Statement and Motivation

High Power EM fields

E

Puls er

Understand and predict the effects of the new electromagnetic threat represented by high power microwave (HPM) and ultrawide band (UWB) pulses on digital electronic systems found inside fixed or moving platforms.

Develop recommendations for performing field tests/measurements

H

External EM Source (Impulse Radiating Antenna)

Illuminated target

Key Achievements and Future Goals

Technical Approach •

Apply electromagnetic topology to predict the effects of HPM/UWB aggressor signals

Fast computer codes are under development at UH, UIUC, UM and OSU.

Apply recently developed fast and accurate computer simulation tools.

Topology studies are underway at CU. Analysis of devices and of processor faults are being conducted at CU and UIC.

Further extend the capabilities of the computer simulation tools to obtain a better understanding of the overall problem.

Validation tests for codes are being developed at CU, OSU, and UIC.


Mitra Dutta, ECE and Michael Stroscio, ECE & BioE Primary Grant Support: ARO, AFOSR (a) 0 1 2

-4

Fluorescence

-3 LUMO

3 4 5 6 7

HOMO

Organic-inorganic hybrid structures enable integration of useful organic and inorganic characteristics for novel applications such as solar cell, chemical sensors, and fluorescent biotags.

Energy transfer in the composite of inorganic quantum dots (QDs) and photosystem I (PS-I) is not understood although it is very important and well studied for photosynthesis.

0 +1

+- +-

+2 CdSe QDs

QDs

-2 -1

En1 Ec hv Ev Eh1

8

Problem Statement and Motivation

NEH(V)

Evac(eV)

+3

PS-I

QDs+PS1

Glass

Glass

Key Achievements and Future Goals

Technical Approach •

Synthesis of the composite of inorganic CdSe QDs and organic PS-I

Observed energy transfer from CdSe QDs to PS-I by optical and electrical measurements.

Experimental measurement of the energy transfer between QDs and PS-I

Photoluminescence data and absorption data show that the energy of excited carriers of CdSe QDs to PS-I by means of radiative emission, FRET, and electron/hole transfer between the inorganic-organic system.

I-V measurement data are sensitive to incident light in the composite CdSe QDs/PS-I material.

Further studies continue to identify each energy transfer method.

Investigation of structural, optical and transport properties by means of photoluminescence, time-resolved photoluminescence, absorption, capacitance-voltage and current-voltage measurements


Investigators: ; M. Dutta, ECE M. Stroscio, ECE and BioE

Problem Statement and Motivation Example of ZnO Nanowires

• Design, fabrication, and characterization of quantum-wire based optoelectronic devices and structures including those incorporating conductive polymers • Design, fabrication, and characterization of quantum-wire based piezoelectric devices and structures for energy harvesting

Technical Approach • Growth of quantum wires

Key Achievements and Future Goals • Numerous simulations of electrical, optical and piezoelectric properties of quantum-wire structures

• Fabrication of quantum-wire based devices • Modeling electrical and optical properties including robustness of quantum-wire-based devices

• Numerous simulations and predictions for a variety of quantum-wire—conductive-polymer structures and piezoelectric structures

• Experimental characterization of integrated structures quantum-wire-based structures

• Demonstrated polarization-dependent light inteactions with arrays of quantum wires • Strong Enhancement of Near-BandEdge PLof ZnO Nanowires


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