Iris segmentation

The quality of eye image data become degraded particularly when the image is taken in the non-cooperative acquisition environment such as under visible wavelength illumination. Consequently, this environmental condition may lead to noisy eye images, incorrect localization of limbic and pupillary boundaries and eventually degrade the performance of iris recognition system. Hence, this study has compared several segmentation methods to address the abovementioned issues. The results show that Circular Hough transform method is the best segmentation method with the best overall accuracy, error rate and decidability index that more tolerant to ‘noise’ such as reflection

Advancement, Spring 2002

Advancement, a supplement to Bostonia magazine, provided updates on BU development activities, including major gifts and projects

3D surface topography and reflectivity of anisotropic etched silicon micromirrors for BioMEMS

This paper examines wet and dry fabrication of vertical micro-mirrors in (110) silicon for use in an innovative BioMEMS integrating gripping and micro force sensing functionalities. Wet anisotropic chemical etching in potassium hydroxide (KOH) and tetramethyl ammonium hydroxide (TMAH) with and without isopropanol alcohol (IPA) additive was examined. Deep Reactive Ion Etched samples were produced using inductive coupled process. 3D surface roughness of samples was examined using scanning electron microscope, interferometric profilometer and atomic force microscopy. An optic fiber displacement sensor was exploited to measure the reflectivity of uncoated or coated samples with evaporated metallic thin film. The research aimed to find optimal fabrication technique for fabricating vertical micro-mirrors in polymer based BioMEMS. TMAH etched silicon samples with surface roughness R a = 15.1 nm showed highest reflectivity of all structures fabricated, reflectivity was more than doubled by adding a 10 nm layer of evaporated aluminum coating

Smart Nanostructures and Synthetic Quantum Systems

So far proposed quantum computers use fragile and environmentally sensitive natural quantum systems. Here we explore the notion that synthetic quantum systems suitable for quantum computation may be fabricated from smart nanostructures using topological excitations of a neural-type network that can mimic natural quantum systems. These developments are a technological application of process physics which is a semantic information theory of reality in which space and quantum phenomena are emergent.Comment: LaTex,14 pages 1 eps file. To be published in BioMEMS and Smart Nanostructures, Proceedings of SPIE Conference #4590, ed. L. B. Kis

Teaching MEMS Curriculum in Electrical Engineering Graduate Program

© ASEE 2010Microelectromechanical Systems (MEMS) refer to devices and systems in the size range of 1 micron (1 micron=10-6m) to 1000 microns. Due to their small size, MEMS technology has the advantages of low weight, low cost, low power consumption and high resolution. MEMS have found broad applications in automobile, inertial navigation, light display, optical and RF communications, biomedicine, etc. World’s MEMS market is growing rapidly each year. To meet the strong market demands on MEMS engineers and researchers, we developed MEMS curriculum in our master program in School of Engineering since Fall 2005. In this paper, we shared our experience in teaching the MEMS curriculum in master program of Electrical Engineering department. Three core courses have been developed for MEMS curriculum. The course description, goals, prerequisites, as well as the topics covered in these courses are discussed. Multimedia technology is used in the teaching to enhance the teaching results. Several MEMS course projects using ANSYS simulation are designed to help student accumulate experience in MEMS device design and simulation. Students are fascinated by the MEMS field and continue their master project/thesis research in MEMS. The MEMS curriculum attracted tremendous interest among students, and the students’ feedback on the course have been excellent. This is part of our efforts to prepare students for the future need of economy revival

A microwave dielectric biosensor based on suspended distributed MEMS transmission lines

Design and characterization of a miniature microwave dielectric biosensor based on distributed microelectromechanical systems (MEMS) transmission lines (DMTL) is reported in this paper. The biosensor has been realized by bonding the DMTL device with an acrylic fluidic channel. In order to demonstrate the sensing mechanism, the sensor is used to detect the small variation of the concentration of aqueous glucose solutions by measuring the electromagnetic resonant frequency shift of the device. It is observed from the results that the second notch of the reflection coefficient (S-11) varies from 7.66 to 7.93 GHz and the third notch of the reflection coefficient varies from 15.81 to 15.24 GHz when the concentration of the glucose solution ranges from 0 to 347 mg/ml, which indicates that higher order notches have higher sensitivities if looking at the absolute change in frequency

Parylene BioMEMS

This paper describes parylene as an emerging bioMEMS material. Parylene has the unique feature of room-temperature, pinhole-free conformal CVD deposition. It is chemically inert and biocompatible. More interestingly, it is found that parylene thin film usually possesses a tensile intrinsic stress, controlled by the last thermal steps. These features allow free-standing parylene MEMS structures in many designs. Parylene MEMS is also a suitable technology for post-CMOS integration. As a result, multi-layer parylene MEMS technology has been developed, especially for bioMEMS applications. This paper also gives examples of integrated parylene microfluidics and HPLC on-a-chip

Flip-chip distributed MEMS transmission lines (DMTLs) for biosensing applications

Design and characterization of a flip-chip distributed MEMS transmission line (DMTL) are presented. The concept of using this DMTL as a biosensor is then introduced. Radio frequency experiments on the DMTL loaded with biosamples have been conducted using the most accessible materials, namely, deionized water and aqueous solutions of salts. Results show that the reflection coefficient (S11) of the solution-loaded DMTL is very sensitive to the salt concentration of the solution in the low-frequency ranges of 10 MHz-1 GHz and 3-4.5 GHz. At high frequencies, the relative dielectric constant of the biosample can also be quantitatively determined from the impedance of the DMTL

Tactile sensing chips with POSFET array and integrated interface electronics

This work presents the advanced version of novel POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) devices based tactile sensing chip. The new version of the tactile sensing chip presented here comprises of a 4 x 4 array of POSFET touch sensing devices and integrated interface electronics (i.e. multiplexers, high compliance current sinks and voltage output buffers). The chip also includes four temperature diodes for the measurement of contact temperature. Various components on the chip have been characterized systematically and the overall operation of the tactile sensing system has been evaluated. With new design the POSFET devices have improved performance (i.e. linear response in the dynamic contact forces range of 0.01–3N and sensitivity (without amplification) of 102.4 mV/N), which is more than twice the performance of their previous implementations. The integrated interface electronics result in reduced interconnections which otherwise would be needed to connect the POSFET array with off-chip interface electronic circuitry. This research paves the way for CMOS (Complementary Metal Oxide Semiconductor) implementation of full on-chip tactile sensing systems based on POSFETs