Papers by Keyword: Microsensors

Abstract: Novel method of manufacturing micro sensors arrays for biomedical applications using BioForce NanoeNablerTM is reported. The operation of pH and glucose sensing elements is based on the properties of polymers, which exhibit a change in their electrical characteristics (such as resistance or capacitance) on exposure to solutions with different concentrations of pH or glucose. A sensor for glucose was successfully fabricated using the enzyme glucose oxidase immobilized within the polymer poly (o-phenylenediamine). This sensor was then successfully miniaturized utilizing immobilization for a dry process. The concentrations used for the microsensor were between 1 mM and 6 mM. Samples containing different concentrations of glucose were applied to the sensor while the system was being monitored for variances in either current or conductance. The resulting changes in the electrical characteristics of the sensor monitored in real time were found to be proportional to the different concentrations of glucose applied. Microscaled interdigitated electrodes were used for sensors array, with 48 sensors places on one chip. It is envisaged that findings of this work would form the basis for miniaturised point-of-care diagnostic system.

Abstract: This paper presents a nonlinear optimization design of microaccelerometer. The sensitivity rates with respect to the structural sizes, for example, length, width, and depth, are simulated before we start the optimal design. Four types of microaccelerometers are investigated that the maxima sensitivity and bandwidth are taken into the design specification. The results meet the requirement of large bandwidth successfully.

Abstract: This paper presents procedures and standards to test tactile and optical microsensors and micro-computed tomography (CT) systems. The tests are similar to the established tests for classical coordinate measuring machines and assess local and global sensor characteristics. For this purpose, adequate and miniaturized reference standards were manufactured, calibrated and tested. In addition, task-specific reference standards have been realized to determine special sensor characteristics such as the maximum slope angle measurable by optical sensors or specific errors of tactile-optical microprobes measuring deep microholes.

Abstract: This paper proposes an improved active homodyne detection technique to compensate for the drift in homodyne measurement. The technique is implemented on a fiber based Michelson interferometer where a computer controller is designed to drive a piezoelectric cylinder attached to one arm of the interferometer. It is shown that the proposed technique can efficiently stabilize the interferometric output.

Abstract: The fuel cell has the potential to become an indispensable source of electric power. However, some problems have not yet been resolved. Measuring the temperature and humidity inside the fuel cells is currently difficult. Accordingly, in this study, micro sensors were fabricated within the fuel cell, in which the temperature and humidity distributions were measured. The substrate of the fuel cell was made of stainless steel (SS-304) and etching was employed to fabricate the channel on the stainless steel substrate. Then micro-electro-mechanical-systems (MEMS) technology was used to fabricate the array micro temperature and humidity sensors on the rib of channel of stainless steel. The advantages of array micro temperature sensors are their small volume, their high accuracy, their short response time, the simplicity of their fabrication, their mass production and their ability to measure the temperature at a precise location more effectively than the traditional thermocouple. The micro humidity sensors were made from gold and titanium as down and up electrodes in the channel. The performance curve of the single cell was operating at 41.54 °C and gas flow rates of H2/O2 at 200/200ml/min. The max power density of the bipolar with micro sensor was 56 mW/cm2.

Abstract: Chemical mechanical polishing (CMP) of platinum thin films was performed for the improvement of surface morphology. Platinum thin films after CMP process with alumina slurry showed the increase of surface morphology without a remarkable difference of the thermal characteristics of as-annealed platinum thin films. The power consumption of platinum thin films micro-heater also became very low by improvement of surface morphology after CMP process. The similar or improved electrical and thermal characteristics of platinum thin films for micro-heater of sensor applications as well as evaluation possibility of sensing property by the improved surface morphology were obtained after CMP process.