This work focusses on the development of a ZnO based piezo-resistive polymer cantilever sensor platform. Two different approaches have been taken, one based on Al-doped ZnO transistor (TFT) embedded in a polymeric mic...
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ISBN:
(纸本)9781467325240
This work focusses on the development of a ZnO based piezo-resistive polymer cantilever sensor platform. Two different approaches have been taken, one based on Al-doped ZnO transistor (TFT) embedded in a polymeric micro-cantilever and another with a ZnO nanowire embedded microcantilever. Low Young's modulus of SU-8, low process temperature and high strain sensing capability of ZnO makes this platform an attractive option for sensorapplications. For both the approaches, electromechanical and mechanical characterization results are reported in this work.
The concept of fiber-Bragg grating (FBG) arrays was investigated regarding its potential to serve as a new method to fabricate cost efficient and high performance pressure sensor catheters for hollow organs. Draw towe...
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ISBN:
(纸本)9781467359825
The concept of fiber-Bragg grating (FBG) arrays was investigated regarding its potential to serve as a new method to fabricate cost efficient and high performance pressure sensor catheters for hollow organs. Draw tower fibers with a reduced diameter of 80 μm and a co-extrusion fabrication process were used in order to keep the catheter simple and prone to be used as one way product. The total diameter of these catheters can range literally from the fiber diameter of 80 μm up to 5 mm. Finite element based investigations on the design were followed by experimental characterization of the material parameters and the fabrication of samples. These samples were thoroughly examined regarding pressure, tension and temperature sensitivity as well as their mechanical properties like stiffness, tensile strength and geometry. As a result of these studies pressure sensor catheter designs for hollow organs in human medicine are proposed. With state of the art interrogation systems for FBG-sensor readout different kinds of measurement catheters are possible to be designed. Possible applications are motility measurements ranging from the human esophagus to the gut, containing rectum, colon and small intestine and even sphincter of Oddi which are accessible by placing the catheter via endoscopic techniques. The use in cardiac arrangements is in preparation.
A number of potentially low-cost time-of-flight (ToF) 3D image sensors aiming at consumer electronics applications have recently appeared in CMOS. Diffused-light sensors taking advantage of SPAD pixels, conventional a...
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A number of potentially low-cost time-of-flight (ToF) 3D image sensors aiming at consumer electronics applications have recently appeared in CMOS. Diffused-light sensors taking advantage of SPAD pixels, conventional and pinned-photodiode lock-in pixels demonstrate centimeter-ranging performance in distances of typically up to 6m, and with the exception of, under low background light (BG) conditions. In those approaches, however, performance tends to rapidly deteriorate in severe BG conditions, such as outdoors, and long-distance ranges have yet to be reported. Another common limitation is their inability to cope with multi-echo target environments. Higher optical signal-to-background ratio (SBR), and hence better performance, is typically achieved by laser-scanning approaches, e.g. employing polygonal or MEMS mirrors. With the emerging need for high-resolution light detection and ranging (LIDAR) technologies in advanced driving-assistance systems (ADAS), we introduce an SoC that performs time-correlated single-photon counting (TCSPC) and complete DSP for a 100m-range ToF sensor. The chip provides the system-level electronics with a serial and low-bit-rate digital interface for: multi-echo distance, distance reliability, intensity, and BG-only intensity, thus mitigating system-level complexity and cost.
This paper presents the development of a ring shaped force sensor for sensorized guidewire applications. The sensor comprises a suspended ring structure located at the center of four suspended beams that can be integr...
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ISBN:
(纸本)9781467359825
This paper presents the development of a ring shaped force sensor for sensorized guidewire applications. The sensor comprises a suspended ring structure located at the center of four suspended beams that can be integrated on the distal tip of a guidewire. SiNWs with a length of 6 μm and a cross section of 90 nm × 90 nm are embedded at the anchor of each silicon bridge as the piezoresistive sensing elements. Taking advantage of the high sensitivity of SiNWs, the fabricated sensor was capable to detect small displacement in nm ranges with a sensitivity of 13.4 × 10~(-3) μm~(-1) in the z-direction. This force sensor showed high linearity (>99.9%) to the applied load and no obvious hysteresis was observed.
Positron-Emission Tomography (PET) is a nuclear imaging technique that provides functional 3-dimensional images of the body, finding its key applications in clinical oncology and brain-function analyses. The typical P...
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Positron-Emission Tomography (PET) is a nuclear imaging technique that provides functional 3-dimensional images of the body, finding its key applications in clinical oncology and brain-function analyses. The typical PET scanner is composed of a ring of scintillator crystals that absorb gamma rays and emit photons as a result, coupled to photon-sensing devices. The photons hit the sensors with a certain spread in space and time, depending on the material and geometry of the crystals. The sensors must then estimate the energy, the time of arrival (ToA), and the axial position of incoming gamma rays. Most commercially available scanners use photomultiplier tubes (PMTs), which are sensitive to magnetic fields, as the sensing element, making the integration of these systems with Magnetic-Resonance Imaging (MRI) impossible. A significant amount of research has focused on replacing PMTs with solid-state detectors, such as Silicon photomultipliers (SiPMs) [1], which can be integrated with MRI while maintaining the high-sensitivity of PMTs.
development of new satellite imagery processing algorithms for resolution enhancement and subpixel analysis allows to increase efficiency of remote sensing applications. Insufficiency of the spatial resolution leads t...
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ISBN:
(纸本)9781479909230
development of new satellite imagery processing algorithms for resolution enhancement and subpixel analysis allows to increase efficiency of remote sensing applications. Insufficiency of the spatial resolution leads to uncertainty in satellite imagery classification and analysis. In this paper we present the technique for satellite imagery spatial resolution enhancement based on subpixel multiple image registration.
This study presents the development of a foundry available process scheme for MEMS devices. Such MEMS process scheme enables integration of various MEMS sensors with Pirani gauge. In applications, this study has emplo...
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ISBN:
(纸本)9781467359825
This study presents the development of a foundry available process scheme for MEMS devices. Such MEMS process scheme enables integration of various MEMS sensors with Pirani gauge. In applications, this study has employed such bulk Si with embedded poly plug process scheme to demonstrate various MEMS devices of different vacuum requirement, including resonators, accelerometer, gyroscope, and magnetometers on single Si wafer. Moreover, a monolithically integrated silicon-based Pirani vacuum gauge to provide in situ pressure monitor for each device is also demonstrated.
Object-detection and classification is a key task in micro- and nanohandling. The microscopy image is often the only available sensor to detect information about the positions and orientations of objects. FPGA-based i...
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Object-detection and classification is a key task in micro- and nanohandling. The microscopy image is often the only available sensor to detect information about the positions and orientations of objects. FPGA-based image processing is superior to state of the art PC-based image processing in terms of achievable update rate, latency and jitter. development of specialized FPGA solutions for object detection and tracking using a hardware-description language is time consuming and requires deep knowledge of the target system. Using SystemC, a C++ based class library, fast implementation with less knowledge of the system is possible. However, the gain in development speed is accompanied by higher resource usage of the FPGA and lower performance regarding computation speed. In this paper, several image processing algorithms are implemented in both manners and are compared regarding achievable update-rate, resource consumption and development time. The SystemC implementations could be implemented twice as fast and with less knowledge about the system. The increased resource usage of SystemC is negligible for small series and prototyping applications, while the decreased computation speed may be problematic for high-speed applications.
Advances in solid-state technology have enabled the development of silicon photomultiplier sensorarrays capable of sensing individual photons. Combined with high-frequency time-to-digital converters (TDCs), this tech...
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Advances in solid-state technology have enabled the development of silicon photomultiplier sensorarrays capable of sensing individual photons. Combined with high-frequency time-to-digital converters (TDCs), this technology opens up the prospect of sensors capable of recording with high accuracy both the time and location of each detected photon. Such a capability could lead to significant improvements in imaging accuracy, especially for applications operating with low photon fluxes such as light detection and ranging and positron-emission tomography. The demands placed on on-chip readout circuitry impose stringent trade-offs between fill factor and spatiotemporal resolution, causing many contemporary designs to severely underuse the technology's full potential. Concentrating on the low photon flux setting, this paper leverages results from group testing and proposes an architecture for a highly efficient readout of pixels using only a small number of TDCs. We provide optimized design instances for various sensor parameters and compute explicit upper and lower bounds on the number of TDCs required to uniquely decode a given maximum number of simultaneous photon arrivals. To illustrate the strength of the proposed architecture, we note a typical digitization of a 60 x 60 photodiode sensor using only 142 TDCs. The design guarantees registration and unique recovery of up to four simultaneous photon arrivals using a fast decoding algorithm. By contrast, a cross-strip design requires 120 TDCs and cannot uniquely decode any simultaneous photon arrivals. Among other realistic simulations of scintillation events in clinical positron-emission tomography, the above design is shown to recover the spatiotemporal location of 99.98% of all detected photons.
Multi-Pixel Photon Counter (MPPC) is a solidstate photon counting device consisting of Geiger-mode APD pixels and self-quenching resistors. The MPPC has attractive features, such as low bias voltage operation, high g...
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Multi-Pixel Photon Counter (MPPC) is a solidstate photon counting device consisting of Geiger-mode APD pixels and self-quenching resistors. The MPPC has attractive features, such as low bias voltage operation, high gain, compact size, robustness and insensitivity to magnetic fields. Therefore, MPPC applications are now being expanded, especially for very low light level measurements. We have developed a new MPPC based PET detector module dedicated to TOF-PET systems. The module consists of a 16 × 16 Lutetium Fine Silicate (LFS) scintillator array with 3.2 mm pitch and a 16 × 16 Through-Silicone-Via (TSV) MPPC array, included analyzing circuits for gamma-ray detection, The performance of the module has been evaluated. The coincidence timing resolution was obtained 440 ps FWHM with a pair of the modules. The energy resolution value was 12.3% at 511 keV. All crystal segments were also clearly separated with uniform irradiation of 511 keV gamma-rays.
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