37 research outputs found

    Wireless Sensor Network for Forest Fire Detection

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     Forest fires are one of problems that threaten sustainability of the forest. Early prevention system for indications of forest fires is absolutely necessary. The extent of the forest to be one of the problems encountered in the forest condition monitoring. To overcome the problems of forest extent, designed a system of forest fire detection system by adopting the Wireless Sensor Network (WSN) using multiple sensor nodes. Each sensor node has a microcontroller, transmitter/receiver and three sensors. Measurement method is performed by measuring the temperature, flame, the levels of methane, hydrocarbons, and CO2 in some forest area and the combustion of peat in a simulator. From results of measurements of temperature, levels of methane, a hydrocarbon gas and CO2 in an open area indicates there are no signs of fires due to the value of the temperature, methane, hydrocarbon gas, and CO2 is below the measurement in the space simulator

    Implantable Piezoresistive Microcantilever-based Wireless Cocaine Biosensors

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    Cocaine is a well-known, illegal, recreational drug that is addictive due to its effects on the mesolimbic reward pathway in the human body. Accurate and real-time measurement of the concentration of cocaine in the body as a function of time and physiological factors is a key requirement for the understanding of the use of this drug. Current methods for such measurements involve taking samples from the human body (such as blood, urine, and hair) and performing analytical chemistry tests on these samples. This techniques are relatively expensive, time consuming, and labor intensive. To address this issue, a new implantable sensor for the automated detection and measurement of the relative cocaine concentration is presented here. The device is more economical and provides for higher sampling frequencies than the current methods. The active sensor elements consist of piezoresistive microcantilever arrays, which are coated with an oligonucleotide-based aptamer, i.e. a short sequence of RNA with high affinity for specific target molecules, as the cocaine receptor. A Wheatstone bridge is used to convert the biosensor signal into an electronic signal. This signal is transmitted wireless at an operating frequency of 403.55 MHz, which complies with the US Medical Implant Communication System (MICS) FCC 47CFR Part 95. The limit of detection for the in vitro experiment is found to be 1 ng/ml. The device has successfully measured the relative concentration of cocaine upon implantation in the subcutaneous interstitial fluid of male Wistar rats

    Wireless Sensor Network for Forest Fire Detection

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    Ultra-thin and flexible CMOS technology: ISFET-based microsystem for biomedical applications

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    A new paradigm of silicon technology is the ultra-thin chip (UTC) technology and the emerging applications. Very thin integrated circuits (ICs) with through-silicon vias (TSVs) will allow the stacking and interconnection of multiple dies in a compact format allowing a migration towards three-dimensional ICs (3D-ICs). Also, extremely thin and therefore mechanically bendable silicon chips in conjunction with the emerging thin-film and organic semiconductor technologies will enhance the performance and functionality of large-area flexible electronic systems. However, UTC technology requires special attention related to the circuit design, fabrication, dicing and handling of ultra-thin chips as they have different physical properties compared to their bulky counterparts. Also, transistors and other active devices on UTCs experiencing variable bending stresses will suffer from the piezoresistive effect of silicon substrate which results in a shift of their operating point and therefore, an additional aspect should be considered during circuit design. This thesis tries to address some of these challenges related to UTC technology by focusing initially on modelling of transistors on mechanically bendable Si-UTCs. The developed behavioural models are a combination of mathematical equations and extracted parameters from BSIM4 and BSIM6 modified by a set of equations describing the bending-induced stresses on silicon. The transistor models are written in Verilog-A and compiled in Cadence Virtuoso environment where they were simulated at different bending conditions. To complement this, the verification of these models through experimental results is also presented. Two chips were designed using a 180 nm CMOS technology. The first chip includes nMOS and pMOS transistors with fixed channel width and two different channel lengths and two different channel orientations (0° and 90°) with respect to the wafer crystal orientation. The second chip includes inverter logic gates with different transistor sizes and orientations, as in the previous chip. Both chips were thinned down to ∼20m using dicing-before-grinding (DBG) prior to electrical characterisation at different bending conditions. Furthermore, this thesis presents the first reported fully integrated CMOS-based ISFET microsystem on UTC technology. The design of the integrated CMOS-based ISFET chip with 512 integrated on-chip ISFET sensors along with their read-out and digitisation scheme is presented. The integrated circuits (ICs) are thinned down to ∼30m and the bulky, as well as thinned ICs, are electrically and electrochemically characterised. Also, the thesis presents the first reported mechanically bendable CMOS-based ISFET device demonstrating that mechanical deformation of the die can result in drift compensation through the exploitation of the piezoresistive nature of silicon. Finally, this thesis presents the studies towards the development of on-chip reference electrodes and biodegradable and ultra-thin biosensors for the detection of neurotransmitters such as dopamine and serotonin

    Design and Development of Low cost spirometer with pc Interface

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    The primary test of lung function is called Spirometry. Spirometry parameters are derived from pressure and/or flow measurements. The spirometer records exhaled air volume, and produces graphic and numeric information in the form of spirometric parameters and tracings that can depict and describe the mechanical properties of the lung. Some possible measurements are like Pressure and gas flows behave during one respiratory cycle in volume controlled. Patient Spirometry measures airway pressures, flow, volumes, compliance, and airway resistance breath-by-breath at the patient’s airway. The flow of gas is measured, and the inspiratory and expiratory concentrations of oxygen and carbon dioxide analyzed. All parameters are measured through a single, lightweight flow sensor and gas sampler, placed at the patient’s airway. The “close to the patient” measurement is a sensitive and continuous reflector of patient’s ventilator status, obtained independently of the ventilator used. The breath-by-breath measurement of pulmonary gas exchange is technically very demanding and requires sophisticated compensation and data processing algorithms to achieve the accuracy required in the clinical use. Measurement of respiratory gas flow continuously is associated with several problems, such as the effects of humidity, alternating gas composition, secretions, and the dynamic response of the flow sensors. Medical technologies have enabled accurate measurement of respiratory gas exchange in a wide variety of clinical conditions. The clinical applications range from assessment of energy requirements to comprehensive analysis of ventilation and oxygen transport in patients with complex cardio respiratory problems. Obstructive disorders, which are much more common than restrictive abnormalities include asthma and COPD. Asthmatic bronchitis, chronic bronchitis, and emphysema are included in COPD. These diseases can be identified by a low FEV / FVC ratio or an FEV that is lower than predicted. Spirometric data have been presented as exhaled volume over time. These volume-time curves are easy to visualize and allow physicians to identify FEV, FVC, and expiratory time at a glance. The flow transducer permits physicians to visualize peak flow and timed peak flow. Which is a check of patients’ efforts FEV, FVC, and FEV, FVC ratio are expressed in terms of lower limit of normal. Here the FEV1/FVC ratio is about the same as (i.e., 57% vs. 59%), but the absolute FEV, is only 66% of predicted. Spirometric measurements can be as fundamental to medicine as are pulse, blood pressure. Temperature, height and weight measurements and therefore could be considered in the physical examination as important vital signs

    Analysis of relevant technical issues and deficiencies of the existing sensors and related initiatives currently set and working in marine environment. New generation technologies for cost-effective sensors

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    The last decade has seen significant growth in the field of sensor networks, which are currently collecting large amounts of environmental data. This data needs to be collected, processed, stored and made available for analysis and interpretation in a manner which is meaningful and accessible to end users and stakeholders with a range of requirements, including government agencies, environmental agencies, the research community, industry users and the public. The COMMONSENSE project aims to develop and provide cost-effective, multi-functional innovative sensors to perform reliable in-situ measurements in the marine environment. The sensors will be easily usable across several platforms, and will focus on key parameters including eutrophication, heavy metal contaminants, marine litter (microplastics) and underwater noise descriptors of the MSFD. The aims of Tasks 2.1 and 2.2 which comprise the work of this deliverable are: • To obtain a comprehensive understanding and an up-to-date state of the art of existing sensors. • To provide a working basis on “new generation” technologies in order to develop cost-effective sensors suitable for large-scale production. This deliverable will consist of an analysis of state-of-the-art solutions for the different sensors and data platforms related with COMMONSENSE project. An analysis of relevant technical issues and deficiencies of existing sensors and related initiatives currently set and working in marine environment will be performed. Existing solutions will be studied to determine the main limitations to be considered during novel sensor developments in further WP’s. Objectives & Rationale The objectives of deliverable 2.1 are: • To create a solid and robust basis for finding cheaper and innovative ways of gathering data. This is preparatory for the activities in other WPs: for WP4 (Transversal Sensor development and Sensor Integration), for WP(5-8) (Novel Sensors) to develop cost-effective sensors suitable for large-scale production, reducing costs of data collection (compared to commercially available sensors), increasing data access availability for WP9 (Field testing) when the deployment of new sensors will be drawn and then realized

    Beyond Tissue replacement: The Emerging role of smart implants in healthcare

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    Smart implants are increasingly used to treat various diseases, track patient status, and restore tissue and organ function. These devices support internal organs, actively stimulate nerves, and monitor essential functions. With continuous monitoring or stimulation, patient observation quality and subsequent treatment can be improved. Additionally, using biodegradable and entirely excreted implant materials eliminates the need for surgical removal, providing a patient-friendly solution. In this review, we classify smart implants and discuss the latest prototypes, materials, and technologies employed in their creation. Our focus lies in exploring medical devices beyond replacing an organ or tissue and incorporating new functionality through sensors and electronic circuits. We also examine the advantages, opportunities, and challenges of creating implantable devices that preserve all critical functions. By presenting an in-depth overview of the current state-of-the-art smart implants, we shed light on persistent issues and limitations while discussing potential avenues for future advancements in materials used for these devices

    SYSTEM-LEVEL APPROACHES FOR IMPROVING PERFORMANCE OF CANTILEVER-BASED CHEMICAL SENSORS

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    This work presents the development of different technologies and techniques for enhancing the performance of cantilever-based MEMS chemical sensors. The developed methods address specifically the sensor metrics of sensitivity, selectivity, and stability. Different techniques for improving the quality and uniformity of deposited sorbent polymer films onto MEMS-based micro-cantilever chemical sensors are presented. A novel integrated recess structure for constraining the sorbent polymer layer to a fixed volume with uniform thickness was developed. The recess structure is used in conjunction with localized polymer deposition techniques, such as inkjet printing and spray coating using shadow masking, to deposit controlled, uniform sorbent layers onto specific regions of chemical sensors, enhancing device performance. The integrated recess structure enhances the stability of a cantilever-based sensor by constraining the deposited polymer layers away from high-strain regions of the device, reducing Q-factor degradation. Additionally, the integrated recess structure enhances the sensitivity of the sensor by replacing chemically-inert silicon mass with ‘active’ sorbent polymer mass. Finally, implementation of localized polymer deposition enables the use of sensor arrays, where each sensor in the array is coated with a different sorbent, leading to improved selectivity. In addition, transient signal generation and analysis for mass-sensitive chemical sensing of volatile organic compounds (VOCs) in the gas phase is investigated. It is demonstrated that transient signal analysis can be employed to enhance the selectivity of individual sensors leading to improved analyte discrimination. As an example, elements of a simple alcohol series and elements of a simple aromatic ring series are distinguished with a single sensor (i.e. without an array) based solely on sorption transients. Transient signals are generated by the rapid switching of mechanical valves, and also by thermal methods. Thermally-generated transients utilize a novel sensor design which incorporates integrated heating units onto the cantilever and enables transient signal generation without the need for an external fluidic system. It is expected that the thermal generation of transient signals will allow for future operation in a pulsed mode configuration, leading to reduced drift and enhanced stability without the need for a reference device. Finally, A MEMS-based micro thermal pre-concentration (µTPC) system for improving sensor sensitivity and selectivity is presented. The µTPC enhances sensor sensitivity by amplifying low-level chemical concentrations, and is designed to enable coarse pre-filtering (e.g. for injection into a GC system) by means of arrayed and individually-addressable µTPC devices. The system implements a suspended membrane geometry, enhancing thermal isolation and enabling high temperature elevations even for low levels of heating power. The membranes have a large surface area-to-volume ratio but low thermal mass (and therefore, low thermal time constant), with arrays of 3-D high aspect-ratio features formed via DRIE of silicon. Integrated onto the membrane are sets of diffused resistors designed for performing thermal desorption (via joule heating) and for measuring the temperature elevation of the device due to the temperature-dependent resistivity of doped silicon. The novel system features integrated real-time chemical sensing technology, which allows for reduced sampling time and a reduced total system dead volume of approximately 10 µL. The system is capable of operating in both a traditional flow-through configuration and also a diffusion-based quasi-static configuration, which requires no external fluidic flow system, thereby enabling novel measurement methods and applications. The ability to operate without a forced-flow fluidic system is a distinct advantage and can considerably enhance the portability of a sensing system, facilitating deployment on mobile airborne platforms as well as long-term monitoring stations in remote locations. Initial tests of the system have demonstrated a pre-concentration factor of 50% for toluene.Ph.D

    Development of biomedical devices for the extracorporeal real-time monitoring and perfusion of transplant organs

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    The goal of this Thesis is to develop a range of technologies that could enable a paradigm shift in organ preservation for renal transplantation, transitioning from static cold storage to warm normothermic blood perfusion. This transition could enable the development of novel pre-implantation therapies, and even serve as the foundation for a global donor pool. A low-hæmolysis pump was developed, based on a design first proposed by Nikola Tesla in 1913. Simulations demonstrated the theoretical superiority of this design over existing centrifugal pumps for blood recirculation, and provided insights for future avenues of research into this technology. A miniature, battery-powered, multimodal sensor suite for the in-line monitoring of a blood perfusion circuit was designed and implemented. This was named the ‘SmartPipe’, and proved capable of simultaneously monitoring temperature, pressure and blood oxygen saturations over the biologically-relevant ranges of each modality. Finally, the Thesis details the successful implementation and optimisation of a combined microfluidic and microdialysis system for the real-time quantitation of creatinine in blood or urine through amperometric sensing, to act as a live renal function monitor. The range of detection was 4.3μM – 500μM, with the possibility of extending this in both directions. This work also details and explores a novel methodology for functional monitoring in closed-loop systems which avoids the need for sensor calibration, and potentially overcomes the problems of sensor drift and desensitisation.Open Acces

    Wireless Sensors and their Applications in Controlling Vibrations

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    As wireless devices are becoming more powerful, more flexible and less costly to produce, they are often being applied in new ways. Combining wireless technology with new types of sensors results in the ability to monitor and control the environment in ways not previously possible. For example, an intelligent wireless sensor system that consists of a sensor, digital processor and a transceiver can be mounted on a board the size of a coin. The data collected by these devices are then transmitted to a central unit which is able to thoroughly process and store this data. Not only can the central processing station provide reports about certain physical parameters in the environment, it can also control the environment and other parameters of interest. The design process of these wireless sensor platforms is a well-developed area of research that covers concepts like networking, circuit design, Radio-Frequency (RF) circuits and antenna design. The design of a wireless sensor can be as simple as putting together a microcontroller, a transceiver and a sensor chip or as complicated as implementing all the necessary circuitry into a single integrated circuit. One of the main applications of the sensors is in a control loop which controls physical characteristics in an environment. Specifically, if the objective of a control system is to limit the amount of vibrations in a structure, vibration sensors such as accelerometers are usually used. In environments where the use of wires is costly or impossible, it makes sense to use wireless accelerometers instead. Among the numerous applications that can use such devices are the automotive and medical vibration control systems. In the automotive industry it is desirable to reduce the amount of vibrations in the vehicle felt by the passengers. These vibrations can originate from the engine or the uneven road, but they are damped using passive mechanical elements like rubber, springs and shocks. It is possible however, to have a more effective vibration suppression using active sensor-actuator systems. Since adding and maintaining wires in a vehicle is costly, a wireless accelerometer can be put to good use there. A medical application for wireless accelerometers can be used with a procedure called Deep Brain Stimulation (DBS). DBS is a relatively new and very effective treatment for advanced Parkinson’s disease. The purpose of DBS is to reduce tremors in the patients. In DBS a set of voltages is applied to the brain of the patient as some optimum combinations of voltages will have a very positive effect on the tremors. Those optimum voltages are currently found by trial and error while a doctor is observing the patient for tremors. Wireless accelerometers with the use of a computer algorithm can assist in this process by finding the optimum voltages using the feedback provided by the accelerometers. The algorithm will assist the doctor in making decisions and has the potential of finding the optimums completely on its own
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