Color biosensors for bacteria
Researcher: Raz Jelinek
Department: Chemistry / IKI
Faculty: Natural Sciences
E-mail: razj@bgu.ac.il
My research aims to address the lack of generic technologies for on-site, rapid bacterials identification. In my laboratory we develop chemical constructs which respond to the presence of bacteria through color changes. The changes are generated in a bio-mimetic platform through the activity of membrane-active molecules secreted by bacteria. The sensor platform is not limited to a particular bacterial species but is rather a versatile, flexible, and task-oriented sensing solution. Application of the proposed sensor technology will not require prior knowledge on the pathogens, and could thus be applied in situations where unknown contaminants are distributed. The sensor assembly is furthermore easy to implement and apply; the induced color changes are both visible to the naked eye and could be also recorded by optical instrumentation. Alternatively, the detection scheme can be based upon fluorescence emitted from the sensor matrix following interactions with the bacterial substances. The simplicity of the detection scheme could make the chromatic platform into a generic tool for alerting as to the presence of bacteria in varied environments.
Sensors - Development of novel and relatively inexpensive focal plane array imagers of mm wave and THz radiation using miniature neon indicator lamps as detectors
Researcher: Natan Kopeika
Department: (1) Electro optical Engineering and (2) Electrical and Computer Engineering
Faculty: Engineering Sciences
E-mail: kopeika@ee.bgu.ac.il
Sensitive real time imaging at mm wave and THz frequencies is usually limited by lack of appropriate inexpensive detectors. We have found that miniature neon indicator lamps costing about 50 cents each exhibit NEP on the order of 10-9 W/Hz1/2 with microsecond order response time at 100-300 GHz. This is easily fast enough for video frame rates. Other advantages include room temperature operation, electronic ruggedness, and linearity of response. The latter makes it possible to use them as mixers in heterodyne detection, in which minimum detectable power can be reduced by orders of magnitude. Small focal plane arrays such as 8X8 pixels have been built, and good quality images obtained with them. They have been used to obtain 32X32 pixel images by moving the array to different locations in the image plane, and imaging at each location a different portion of the object. The sum of 16 such images then yields a 32X32 pixel image. Superresolution image restoration has also been implemented. Presently, a 32X32 pixel board is under construction so as to yield 32X32 pixels with a single snapshot. Both conducting and dielectric objects are imaged. Image quality is essentially the same as that with Schottky diode detectors. Applications can include imaging through obstructing dielectric media such as clothing, suitcases, etc., as well as through walls [depending on conductivity]. There are also many biological and medical applications for imaging at such frequencies. Future plans, depending on funding, include increasing the number of pixels, implementing heterodyne detection so as to increase imaging range, and implementing compressive imaging so as to significantly improve resolution.
Adhesion force measurement between explosive particles and various substrates, particle sampling and numerical simulations of detonation processes using reactive molecular dynamics calculations
Researcher: Yehuda Zeiri
Department: Biomedical
Faculty: Engineering
E-mail: yehuda@bgu.ac.il
We measure the adhesion forces between particles in general and various substrates. The force measurement is carried out using two different methods: force measurement using an atomic force microscope (AFM) and utilization of the aerodynamic approach. In the aerodynamic method one employs a short pulse of an inert gas jet to remove particles attached to the substrate. The experiment is carried out under an optical microscope and allows us to compare the images before and after the gas jet pulse to obtain information related to adhesion forces. This approach allows a comparative study in contrast to the AFM experiments in which the actual adhesion force between a single particle and the substrate is obtained.
In addition to these experiments we also investigate ways to improve sample collection mainly when using the swab collection (as is the case in all airports today). This part of the research is accompanied by the use of high sensitivity analytical methods for quantitative analysis of explosive traces.
The theoretical part of our research deals mainly with atomic level simulations of detonation processes. The main tool is a molecular dynamics code that incorporates a reactive force field. This method allows us to study the detailed chemical reactions that accompany the detonation process when the shock wave passes through the explosive material. This approach allows us to obtain reaction products distributions at various isothermal and isobaric conditions that are relevant to the detonation process.
Subsurface Detection – Magnetic sensors
Researcher: Evgeny (Eugene) Paperno
Department: E&CE
Faculty: Engineering Sciences
E-mail: paperno@ee.bgu.ac.il
Magnetic sensors and magnetometers, including atomic magnetometers planar Hall effect sensors, magneto-electric sensors, search coils, fluxgates, AMR, sensor networks, magnetic tracking systems, magnetic shielding, low-noise and low-power electronics, magnetic and electronic instrumentation.
