[show abstract][hide abstract] ABSTRACT: The paper presents an implemented architecture of a software platform used in a master program from our university. The interactive teaching consists in online courses and virtual laboratories about electronics devices simulation, circuit optimisation and biocomponents analysis. The software is based on Core and Collaboration components from the Lotus LearningSpace package. Both a demonstrative course and virtual laboratory are included in the first step of the Core component installing. After the Collaboration component set-up, whiteboard and live session are used. Then some applications concerning microelectronics and bio-components simulation are presented, as a collaborative work from the e-Learning environment. The implemented platform gives the possibility to integrate the poor universities in the international framework and to make the national qualifications more readable.
[show abstract][hide abstract] ABSTRACT: A new challenge in the biomedical engineering is the remote patient monitoring by web applications. This paper proposes a first instance of diagnosis that guide the patients to a first medical point, with the advantage of a flexible structure, suitable for the next web developers, like students from bioinformatics universities. These kinds of applications stand for a sub-component of the telemedicine, as web-assisted medical E-healthcare diagnosis points. A diseases-symptoms database was uploaded in order to establish a final diagnosis. The main scope of this article is to offer a web protocol for medical diagnosis, under educational projects, as application to learning, bioinformatics and telemedicine. The paper presents an original software developed in HTML and its subsidiaries, as a flexible student environment.
Data Compression, Communications and Processing (CCP), 2011 First International Conference on; 07/2011
[show abstract][hide abstract] ABSTRACT: The paper presents a hardware solution of the in vivo electrophysiological signals processing, using a continuous data acquisition on PC. The originality of the paper comes from some blocks proposal, which selective amplify the bio signals. One of the major problems in the electrophysiological signals monitoring is the impossibility to record the weak signals from deep organs that are covered by noise or by strong cardiac or muscular signals. An automatic gain control block is used, so that the high power skin signals are less amplified than the low components. The analog processing block is based on a dynamic range compressor, containing the automatic gain control block. The following block is a clipper since to capture all the transitions that escape from the dynamic range compressor. At clipper output a low-pass filter is connected since to abruptly cut the high frequencies, like 50Hz, ECG. The data vector recording is performing by strong internal resources micro controller including ten bits A/D conversion port.
First International Conference on Data Compression, Communications and Processing, CCP 2011, Palinuro, Cilento Coast, Italy, June 21-24, 2011; 01/2011
[show abstract][hide abstract] ABSTRACT: In the industrial chain of the nanomaterials for electronic devices, a main stage is represented by the wafer characterization. This paper is starting from a standard SOI wafer with 200 nm film thickness and is proposing two directions for the SOI materials miniaturization, indexing the static characteristics by simulation. The first SOI nanomaterial is a sub-10 nm Si-film with a rectangular shape. The influence of the buried interface fixed charges has to be approached by the distribution theory. The second proposal studies the influence of the vacuum cavity in a “U” shaped SOI nanofilm. In all cases, with rectangular or “U” shape film, the simulations reveal transfer characteristics with a maximum and output characteristics with a minimum for sub-10 nm thickness of the SOI film.
Journal of Nanomaterials 01/2011; 2011. · 1.55 Impact Factor
[show abstract][hide abstract] ABSTRACT: A brief presentation of the NOI — Nothing On Insulator — nanotransistor, followed by two theoretical points of view concerning the NOI-FET non-linearity are presented in this paper. The main target is to prove the NOI nanotransistor affiliation to the FETs family, monitoring the gate-control on the drain current. The drain current is activated by the VDS voltage under tunneling conditions. The gate terminal modulates the carriers concentration and consequently the drain current flow. Secondary, a new model parameter comes to complete the NOI-FET theory. The third order derivative was used for the extraction of a threshold drain-source voltage that splits the work domain in two conduction regions: weak and strong.
[show abstract][hide abstract] ABSTRACT: This paper presents the TCAD techniques used for the simulation, optimisation and design of the BioFET device parameters, using a specialised software package, ATLAS. The values of these parameters will prescribe the process fabrication and device size. Using EDA tools like LEDIT, the layers that will constitute the fabrication masks for both active and reference devices will be established, as a first novelty of this paper. A biodevice description in Atlas program, including an enzyme within the gate space, represents a second original approach. Besides to the simulations and mask design, the paper exposes some comparative experimental results concerning a nanostructured material, suitable for the enzyme entrapping.
[show abstract][hide abstract] ABSTRACT: This paper presents the simulation results of the gate-controlled diode, working in the analog regime. The aim of the paper is to find the device macromodel that provides an optimum linearity of the junction voltage versus the gate voltage, at a given current. The lateral pn junction is simulated in the breakdown regime and the gate voltage biases the MOS capacitor in deep depletion. Finally, linearity under 1% was accomplished, being in agreement with the theory. An equivalent circuit was developed according to these simulations in order to be implemented in Spice like programs.
[show abstract][hide abstract] ABSTRACT: The paper presents the aspects of design and implementation of a chain for electrophysiological signal recording, respectively
collection, analog processing and digital data recording. The analog processing is based of dynamic range compressor circuit
composed by the automatic gain control with a recovery delay to minimize the distortions, thermal behavior compensation and
an adaptation stage for levelmeter. At compressor output was added a clipper, which must catch all the transitions, that escapes
out of the dynamic range compressor and at clipper output a lowpass filter to cuts abruptly the high frequencies. The data
vector recording is performing by strong internal resources microcontroller including ten bits A/D conversion port.
Keywordsbioelectronics-analog processing-digital recording
[show abstract][hide abstract] ABSTRACT: This paper presents the enhanced performances of a glucose biosensor constructed with a dielectric multi-layer Si/SiO2/Si3N4/Al2O3. If the Si/SiO2 system is present in all the silicon integrated sensors, the biosensors processing involves special attention to the intermediate
layer responsible for the biological receptors entrapping. A first experience imposes to use the Si3N4 layer over the SiO2 layer mainly to stops the Na+ and K+ ions diffusion from bio-environment toward the silicon transducer. These results are
reflected in the CV traced curve and a minimum leakage current. The nitride besides to a nanometric top Al2O3 layer grown by anodization, helps to a better enzyme entrapping, maintains the GOD active centers and are in agreement with
the planar technology requirements. An original Al2O3 deposition technique is presented. The final multilayer structure was characterized as a capacitor by CV-metry, ellipsometry,
[show abstract][hide abstract] ABSTRACT: This paper presents the simulations results and preliminary experiments of a glucose BioFET constructed with a dielectric multi-layer Si/SiO<sub>2</sub>/Si<sub>3</sub>N<sub>4</sub>/Al<sub>2</sub>O<sub>3</sub>. Beside to the Si/SiO<sub>2</sub> system, the biosensors processing involves special attention to the intermediate layer responsible for the biological receptors entrapping. A first experience imposes to use the Si<sub>3</sub>N<sub>4</sub> layer over the SiO<sub>2</sub> layer mainly to stops the Na<sup>+</sup> and K<sup>+</sup> ions diffusion from the bioenvironment toward the silicon transducer. The nitride beside to a porous top Al<sub>2</sub>O<sub>3</sub> layer grown by anodization, helps to a better enzyme entrapping, maintains the GOD active centres and are in agreement with the planar technology requirements. An original Al<sub>2</sub>O<sub>3</sub> deposition technique is presented. The final multilayer structure was characterized as a capacitor using a CV-meter and an ellipsometer.
Semiconductor Conference, 2009. CAS 2009. International; 11/2009
[show abstract][hide abstract] ABSTRACT: The modern medicine cannot be conceived without the latest news in engineering technology. One of the challenges is related to the novel energy source inside the human body that can be useful for implantable devices, as pacemakers or in vivo insulin micropumps or biosensors. In this paper, the biofuel properties of the glucose that is regulated within the endocrine pancreas, is analyzed in order to offer alternative methods to biogenerators, using the inside glucose from the bloodstream itself. The glucose concentration is regulated by the beta cells activity, via the insulin hormone released in the bloodstream. The insulin exocytose in 7 steps is modeled as a digital system, expressed in an organigram, proving the cellular self-organizing. The exocytose phenomenon is accompanied by electrical behavior at membranar level. The entire electrophysiological model of the beta cell is analyzed in order to offer a useful model for diagnosis in medicine, using the inside glucose from the bloodstream.
Clean Electrical Power, 2009 International Conference on; 07/2009
[show abstract][hide abstract] ABSTRACT: This paper presents the simulations results of some biological nanostructures. A first class refers to the electrical transmembranar voltage simulation with a software borrowed from microelectronics devices. The property of insulator is proved for the lipidic bilayer. The membrane contains ion channels with ~2 nm width. Through these nano-pores the water molecules cross in/out of cell. The flow properties in these nano-channels are impossible to be experimentally investigated. Simulations of nanofluidics present the velocity distribution, the vorticity and the laminar flow inside the inner layer.
[show abstract][hide abstract] ABSTRACT: One of the challenges in the biomedical engineering domain is the Telemedicine. The remote diagnosis, automate instruments for drug delivery or mobile platforms for domestic applications are common targets accepted by the medical insurance companies form the world wide. The Telemedicine need the development of various tools for home analysis, in order to send all the collected analysis to a medical center or to a database on Internet. In this paper is proposed a simple and cheap platform for the Electro-cardio-gram recording on the Personal Computer. The platform consists in a hardware part and a software part. The general electrical circuit for the ECG recording was adapted in order to be available at home applications. The amplified signal is then connected via the microphone muff to PC. A dedicated software converts the input ldquonoiserdquo signal into an ECG trace. In this way, the ECG becomes available, in the simpler mode directly on the computer screen, without any expensive tracer.
Semiconductor Conference, 2008. CAS 2008. International; 11/2008
[show abstract][hide abstract] ABSTRACT: The electrical properties of the chemical mediators at synapses level could be investigated in vitro, with some test biodevices. One of neurotransmitters, like epinephrine, placed on an insulator support and contacted with metal electrodes, provides a Biomaterials On Insulators - BOI-type, structure. The test device is inspired from the pseudo-MOS technique, frequently used in the Silicon On Insulator characterisation. The DC regime study allows some polarography experiments. A behavior like the Field Effect Transistor was also investigated in DC regime, biasing a third terminal - the gate. A gate voltage control on the current is expected. It is still linear, emphasising none inversion layer onset. The AC regime measurements of the BOI device provided some conductometry results, providing the epinphrine resistivity.
Semiconductor Conference, 2008. CAS 2008. International; 11/2008
[show abstract][hide abstract] ABSTRACT: This paper reports the feed-back from a pilot new course, proposed in 2005 and accepted in 2006 for next years at the Polytechnic University of Bucharest, Romania, Faculty of Electronics, Microsystems Specialization at master studies. The BioNEC course entitled Biodevices and Cellular Nano-Electronics is dedicated to the Biosensors, Biosignals and Biomodeling, accordingly with the European curricular area. Placed at the cross-point of Biology and Electronics Engineering, this course intends to familiarize the future engineers with the new trends, products and applications in bio-engineering.
[show abstract][hide abstract] ABSTRACT: An inherent SOI device dedicated for the in situ electrical characterization of wafers is the pseudo-MOS transistor that easily provides a key parameter: Flat-Band Voltage, VFB. Usual models for this voltage were established for SOI structures with 0,2mum...2mum film thickness and 0,4...100mum oxide thickness. The classical models of VFB, deduced for micronic sizes, present some deficiencies in the nanodevice area. An interface charge about 1012e/cm2 in micronic sizes means 1e/100nm2 equivalent with one electron per device area in the nano-domain. This paper analyses the flat-band voltage modeling, due to the consequences of the down-scaling of the SOI wafers.
[show abstract][hide abstract] ABSTRACT: An MOSFET with a piezoelectric layer instead of the gate insulator represents a sensitive device at a mechanical pressure stimulus. If the SOI structure is modified so that significant currents occur in the V<sub>c</sub>=0 V vicinity, a higher sensitivity is ensured. In a SOI-MOSFET this aim was possible using shallow diffusions n<sup>+</sup>p about 40...60 nm. An analytical model of the transducer element and ATLAS simulations revealed the electrical behavior of the device. There were comparatively presented the transfer characteristics of a classical SOI-MOSFET, a pseudo-MOS transistor and a modified SOI transistor with shallows diffusions. The last one represents a trade-off solution for a pressure sensor that needs high response in the zero gate voltage vicinity.
Semiconductor Conference, 2007. CAS 2007. International; 01/2007