Field Effect Transistor Nanosensor for Breast Cancer Diagnostics

Silicon nanochannel field effect transistor (FET) biosensors are one of the most promising technologies in the development of highly sensitive and label-free analyte detection for cancer diagnostics. With their exceptional electrical properties and small dimensions, silicon nanochannels are ideally suited for extraordinarily high sensitivity. In fact, the high surface-to-volume ratios of these systems make single molecule detection possible. Further, FET biosensors offer the benefits of high speed, low cost, and high yield manufacturing, without sacrificing the sensitivity typical for traditional optical methods in diagnostics. Top down manufacturing methods leverage advantages in Complementary Metal Oxide Semiconductor (CMOS) technologies, making richly multiplexed sensor arrays a reality. Here, we discuss the fabrication and use of silicon nanochannel FET devices as biosensors for breast cancer diagnosis and monitoring

Performance of pilot scale plug flow microbial fuel cell for sustainable wastewater treatment and energy recovery

Wastewater is increasingly considered a resource rather than a problem. This study investigates the rapidly developing Microbial Fuel Cell technology and its potential to be used in an industrial scale and environment in the context of the whisky industry and to be used as an alternative or complementary sustainable wastewater treatment process. This study describes the development of a 122 litre multi-electrode open air cathode Microbial Fuel Cell. Throughout this study the reactor’s performance is assessed on two levels; energy recovery and effluent quality. During initial studies the principle of the MFC’s ability to treat whisky distillation by-products was established. The reactor was operated directly on diluted spent wash in ambient Scottish temperatures. During successful start-up, no correlation was found to temperature. During long-term operation, a positive correlation was found between temperature and the positive energy balance achieved by the MFC while tCOD removal efficiency was maintained at approximately 83 %. The reactor was further optimised in regards to electrical connections, thus its electrical performance which was also validated through a bench scale study. The successful initial experiments led to the integration of an operationally optimised pilot study in a local whisky distillery. The pilot set-up was successfully operated complementary to an anaerobic digester for over one year in the industrial environment achieving energy savings and a sustainable tCOD removal efficiency of over 80 %. Latterly, a simplified electrochemical model was examined to describe the performance of the MFC to be further developed. This study concludes that the nature of industrial wastewater treatment is a complex subject and equally so is the multi-disciplinary MFC technology. The MFC developed for this study and the industrial experience gained contributes towards a more sustainable, energy saving and efficient treatment technology with the potential to be used complementary to existing technologies

Southwest Research Institute assistance to NASA in biomedical areas of the technology utilization program Final report, 1 Feb. 1969 - 24 Aug. 1970

Research progress in technology transfer by NASA Biomedical Application Tea

Sustainable Waste-to-Energy Technologies: Bioelectrochemical Systems

The food industry produces a large amount of waste and wastewater, of which most of the constituents are carbohydrates, proteins, lipids, and organic fibers. Therefore food wastes are highly biodegradable and energy rich. Bioelectrochemical systems (BESs) are systems that use microorganisms to biochemically catalyze complex substrates into useful energy products, in which the catalytic reactions take place on electrodes. Microbial fuel cells (MFCs) are a type of bioelectrochemical systems that oxidize substrates and generate electric current. Microbial electrolysis cells (MECs) are another type of bioelectrochemical systems that use an external power source to catalyze the substrate into by-products such as hydrogen gas, methane gas, or hydrogen peroxide. BESs are advantageous due to their ability to achieve a degree of substrate remediation while generating energy. This chapter presents an extensive literature review on the use of MFCs and MECs to remediate and recover energy from food industry waste. These bioelectrochemical systems are still in their infancy state and further research is needed to better understand the systems and optimize their performance. Major challenges and limitations for the use of BESs are summarized and future research needs are identified

Space Station RT and E Utilization Study

Descriptive information on a set of 241 mission concepts was reviewed to establish preliminary Space Station outfitting needs for technology development missions. The missions studied covered the full range of in-space technology development activities envisioned for early Space Station operations and included both pressurized volume and attached payload requirements. Equipment needs were compared with outfitting plans for the life sciences and microgravity user communities, and a number of potential outfitting additions were identified. Outfitting implementation was addressed by selecting a strawman mission complement for each of seven technical themes, by organizing the missions into flight scenarios, and by assessing the associated outfitting buildup for planning impacts

The performance of varying PTFE coated fabric cloth on electricity production using synthetic wastewater with aid of activated carbon air-cathode

M.Tech. (Chemical Engineering)Abstract: Microbial fuel cell is the energy harvesting technology being studied; this technology concerns various substrates, microbes and wastewater into electrical energy by the catalytic reaction of micro-organisms. The thesis of the project research seeks to establish a comparison in the performance of biochemical properties for microbial fuel cells using synthetic wastewater and activated carbon. The cathode electrode used was a stainless steel pressed with activated carbon and was sectioned to a surface area of 36cm2 same with the proton exchange membrane and the carbon cloths were also sectioned at 36cm2. The experimental set-up consisted of a double chamber membrane which consisted of the anode and air-cathode chamber. The anode and air-cathode chamber were immersed in the open water bath regulated at a temperature of 35oC. On the start-up, the anode chamber was filled with 280ml of synthetic wastewater which was mixed and prepared in the lab to reach the ideal COD levels which meet the raw domestic wastewater COD levels and the air-cathode was filled with 8L of tap water. The anode chamber after every experiment was changed and fitted with a new and different carbon cloth coating, whereby the cathode chamber had to be changed with an addition of the pulverized activated carbon. The 50% PTFE coated carbon cloth is more efficient in generating power than the other which were compared to in the experiment; however the performance of individual carbon cloths varies significantly with the type or percentage of coating added and this directly affects the overall performance of the MFC, and this was highly aided with the addition of the activated carbon. An air-cathode with activated carbon with different particle sizes which was embedded on a stainless steel mesh. Microbial fuel cell (MFC) containing synthetic wastewater was constructed and compared to different types of carbon coated polytetrafluroethylene (PTFEs). The synthetic wastewater contained in MFCs was investigated and together with the aid of activated carbon which was pulverized to different sizes for oxygen removal. The synthetic wastewater MFC had a power output of 86.80mW/m2, compared to 17.47mW/m2 for the domestic wastewater. The limiting current density is 0.0347mA/m2 for the activated carbon in synthetic wastewater compared to 0.0046mA/m2 for domestic wastewater without an..

Stacking of IGBT devices for fast high-voltage high-current applications

The development of solid-state switches for pulsed power applications has been of considerable interest since high-power semiconductor devices became available. However, the use of solid-state devices in the pulsed power environment has usually been restricted by device limitations in either their voltage/current ratings or their switching speed. The stacking of fast medium-voltage devices, such as IGBTs, to improve the voltage rating, makes solid-state switches a potential substitute for conventional switches such as hard glass tubes, thyratrons and spark gaps. Previous studies into stacking IGBTs have been concerned with specific devices, designed or modified particularly for a specific application. The present study is concerned with stacking fast and commercially available IGBTs and their application to the generation of pulsed electric field and the switching of a high intensity Xenon flashlamp. The aim of the first section of the present study was to investigate different solid-state switching devices with a stacking capability and this led to the choice of the Insulated Gate Bipolar Transistor (IGBT). It was found that the collector-emitter voltage decreases in two stages in most of the available IGBTs. Experiments and simulation showed that a reason for this behaviour could be fast variations in device parasitic parameters particularly gate-collector capacitance. Choosing the proper IGBT, as well as dealing with problems such as unbalanced voltage and current sharing, are important aspects of stacking and these were reported in this study. Dynamic and steady state voltage imbalances caused by gate driver delay was controlled using an array of synchronised pulses, isolated with magnetic and optical coupling. The design procedure for pulse transformers, optical modules, the drive circuits required to minimise possible jitter and time delays, and over-voltage protection of IGBT modules are also important aspects of stacking, and were reported in this study. The second purpose of this study was to investigate the switching performance of both magnetically coupled and optically coupled stacks, in pulse power applications such as Pulse Electric Field (PEF) inactivation of microorganisms and UV light inactivation of food-related pathogenic bacteria. The stack, consisting of 50 1.2 kV IGBTs with the voltage and current capabilities of 10 kV, 400 A, was incorporated into a coaxial cable Blumlein type pulse - generator and its performance was successfully tested with both magnetic and optical coupling. As a second application of the switch, a fully integrated solid-state Marx generator was designed and assembled to drive a UV flashlamp for the purpose of microbiological inactivation. The generator has an output voltage rating of 3 kV and a peak current rating of 2 kA, although the modular approach taken allows for a number of voltage and current ratings to be achieved. The performance of the switch was successfully tested over a period of more than 10⁶ pulses when it was applied to pulse a xenon flashlamp.The development of solid-state switches for pulsed power applications has been of considerable interest since high-power semiconductor devices became available. However, the use of solid-state devices in the pulsed power environment has usually been restricted by device limitations in either their voltage/current ratings or their switching speed. The stacking of fast medium-voltage devices, such as IGBTs, to improve the voltage rating, makes solid-state switches a potential substitute for conventional switches such as hard glass tubes, thyratrons and spark gaps. Previous studies into stacking IGBTs have been concerned with specific devices, designed or modified particularly for a specific application. The present study is concerned with stacking fast and commercially available IGBTs and their application to the generation of pulsed electric field and the switching of a high intensity Xenon flashlamp. The aim of the first section of the present study was to investigate different solid-state switching devices with a stacking capability and this led to the choice of the Insulated Gate Bipolar Transistor (IGBT). It was found that the collector-emitter voltage decreases in two stages in most of the available IGBTs. Experiments and simulation showed that a reason for this behaviour could be fast variations in device parasitic parameters particularly gate-collector capacitance. Choosing the proper IGBT, as well as dealing with problems such as unbalanced voltage and current sharing, are important aspects of stacking and these were reported in this study. Dynamic and steady state voltage imbalances caused by gate driver delay was controlled using an array of synchronised pulses, isolated with magnetic and optical coupling. The design procedure for pulse transformers, optical modules, the drive circuits required to minimise possible jitter and time delays, and over-voltage protection of IGBT modules are also important aspects of stacking, and were reported in this study. The second purpose of this study was to investigate the switching performance of both magnetically coupled and optically coupled stacks, in pulse power applications such as Pulse Electric Field (PEF) inactivation of microorganisms and UV light inactivation of food-related pathogenic bacteria. The stack, consisting of 50 1.2 kV IGBTs with the voltage and current capabilities of 10 kV, 400 A, was incorporated into a coaxial cable Blumlein type pulse - generator and its performance was successfully tested with both magnetic and optical coupling. As a second application of the switch, a fully integrated solid-state Marx generator was designed and assembled to drive a UV flashlamp for the purpose of microbiological inactivation. The generator has an output voltage rating of 3 kV and a peak current rating of 2 kA, although the modular approach taken allows for a number of voltage and current ratings to be achieved. The performance of the switch was successfully tested over a period of more than 10⁶ pulses when it was applied to pulse a xenon flashlamp