IMG Seminar

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.

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.

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.

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.

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.

Matias Oyarzun will give a tutorial on how to correctly use the Laser Displacement Sensor which is typically used to measure vibrations. All of IMG is encouraged to attend.

Refreshments will be provided.

Please note that this week's seminar is from 4PM (not 3PM) due to speaker's conflict.

Snacks and drinks will be served

Speaker: David Senior

Abstract: Highly compact metamaterial devices are demonstrated by combining the composite right-left handed transmission line approach with a multilayer surface micromachined fabrication processusing SU8 as a dielectric layer. Multiband microwave metamaterial applications for ISM frequencies of 2.4GHz and 5.8GHz are implemented The use of microfabrication techniques eliminates the necessity of using surface mounting device (SMD) based lumped components and makes the CRLH structures compatible and integrable with CMOS/MEMS processes while allowing batch fabrication of multiple devices.

Please note that this week's seminar is from 4PM (not 3PM) due to speaker's conflict.

Snacks and drinks will be served

Speaker: Cheolbok Kim

Abstract: Modern satellite communication systems often demand low-profile, wide bandwidth, high gain, and circular polarization antennas. For this applications, a high gain circular polarization antenna with metamaterial slabs has been proposed. Metamaterial slabs having periodic circular lattices have been used to focus beam while fan-shaped patches are added on the slabs to generate circular polarization. The proposed antenna has shown a good axial ratio at the resonant frequency band. It also has shown a simulated gain improvement and transmission gain improvement. In addition, the left/right handed polarization is simply controlled by turning over metamaterial slabs.

Speaker: PitFee Jao

The direction of cell growth is associated with chemical, structural and/or mechanical properties of the substrate. Structurally, electrospun nanofibers provide a suitable environment for cell attachment and proliferation due to their similar physical dimension to that of the extracellular matrix. Furthermore, by modulating the topographical features of nanofibers, which include fiber diameter and orientation, cell growth and its related functions can be modified. Here, we demonstrate a solid gradient scaffold for directional growth of spiral ganglion neurons (SGNs).