Dr. Lou Cattafesta elected as a Fellow of ASME

Dr. Cattafesta was elected as a Fellow of the American Society of Mechanical Engineers (ASME).  A quotation from ASME reads

"Professor Cattafesta has contributed seminal contributions to the development and implementation of and education concerning active flow control systems, with particular emphasis on novel actuators and methods for closed-loop flow control experiments."

IMG Seminar: Capacitive shear stress sensor and its interface circuitry

Event date: 
Wed, 11/17/2010 - 9:00pm to 10:00pm

Speaker: Jessica Meloy

Introduction: The time-resolved characterization of complex wall-bounded flow fields is difficult and unachievable with the current set of research tools. At the University of Florida the Interdisciplinary Microsystems Group (IMG) has teamed with FCAAP to develop the next generation of instrumentation grade sensors for aerospace applications. Specifically, microelectromechanical systems (MEMS) technology is being used to develop sensor systems for reliable direct time-resolved shear stress measurement and fill this instrumentation void. IMG has developed a robust miniaturized package for integration into flow control studies currently being conducted at both the Advanced Aero-Propulsion Laboratory at Florida State University and at IMG wind tunnel facilities at the University of Florida. The specific sensor system being utilized in these studies is capable of measuring shear stress values as low as 1mPa with a sensitivity of 1.7mV/V/Pa and at least 80dB rejection to cross sensitivities. In this seminar the sensor system’s circuitry and package development will be discussed.

Electromechanical inductor for power converter applications

Event date: 
Wed, 11/10/2010 - 8:00pm to 8:30pm

Speaker: Yaxing Zhang

Introduction: The presentation will focus on the concept, theory, and demonstration of electromechanical inductors that couple an electrical conductor with a mechanical energy storage component in order to boost the electrical inductance over a specific frequency band. Measurements of mesoscale prototypes indicate an inductance boost >10,000x compared to static electrical devices. The results show as a step toward ultra-high-inductance-density microfabricated devices intended to dramatically reduce the size and mass of switched-mode power supplies.

Refreshments will be served.

IMG Seminar: Two-Axis Scanning Micromirror Based on A Tilt-and-Lateral Shift-Free Piezoelectric Actuator

Event date: 
Wed, 10/27/2010 - 8:30pm to 9:00pm

Speaker: Wenjing Liu

Introduction: This talk is about the design, fabrication and characterization of a piezoelectrically actuated high-fill-factor tip-tilt-piston (TTP) micromirror with nearly zero initial tilt and no lateral shift during scanning. The piezoelectric material is a sol-gel lead zirconate titanate (PZT) thin film with a Zr/Ti ratio of 53/47. The zero-initial-tilt (ZIT) and lateral-shift-free (LSF) of the mirror plate is achieved by a folded, three-segment piezoelectric unimorph actuator design. The piezoelectric unimorph actuation beams consist of Pt/Ti/PZT/Pt/Ti/SiO2 multilayers, which are released via undercutting the substrate silicon.

Refreshments will be served.

IMG Seminar: CMOS-MEMS inertial measurement unit (IMU)

Event date: 
Wed, 10/27/2010 - 8:00pm to 8:30pm

Speaker: Hongzhi Sun

Introduction: IMUs have wide automotive, consumer electronics, and medical applications. The focus of this talk is on a three-axis accelerometer and two single-axis gyroscopes. The presentation will include the CMOS-MEMS process, the interface circuit design, and the characterizations for the monolithic IMU.

Refreshments will be served.

IMG Seminar: Capabilities and Applications of Laser Doppler Velocimetry (LDV)

Event date: 
Thu, 10/21/2010 - 7:00pm to 8:00pm

Nik Zawodny will present the basic principles of Laser Doppler Velocimetry (LDV) as well as a cataloging of the LDV processing and data analysis capabilities available to IMG members. LDV is a non-intrusive optical technique for measuring fluid particle velocities at a single point. LDV is a highly stable measurement process that at times can be superior to Particle Image Velocimetry (PIV), with its ability to measure velocities in regions that cannot be illuminated with a laser light sheet.

IMG Seminar: Beamforming Fundamentals and Practical Applications

Event date: 
Thu, 10/14/2010 - 7:00pm to 8:00pm

Presenter: Chris Bahr, Ph.D.

Description: In aeroacoustic testing, the determination of acoustic source locations in an experiment is often critical, as the sources must be located before they can be mitigated.  One of the most common techniques used to determine source locations, known as beamforming, utilizes an array of microphones and acoustic source modeling.

In this presentation, the classic delay-and-sum (DAS) beamformer is discussed in both the time and frequency domains from a theoretical perspective.  Common implementations of the beamformer as used in wind tunnel testing are then shown, with discussion of appropriate usage and corrections.