Direct Bonding SOI Wafer Based Cantilever Resonator for Trace Gas Sensor Application

A thermal driving and piezoresistive sensing MEMS cantilever resonator has been proposed and developed to construct trace gas detection sensors. The problem of integrating vibration structure, transducers and electric elements is the main concern in the design and fabrication of the resonator. In this paper, the parameters and the configuration of the resonator are discussed, the fabrication process and the test results are presented. Finite Element Analysis (FEA) has been carried out to optimize the configuration of the resonator to obtain high sensitivity and efficiency with a uniform temperature distribution that is propitious to the function of the gas sensing material. The fabrication process is based on direct bonding silicon-on-insulator (SOI) wafer and inductive coupled plasma (ICP) etching technology, which conciliate the semiconductor processes and the micromaching processes, and provide precise control of the resonator parameters. The experimental test results of the fabricated resonator agreed well with the calculation and simulation results and demonstrated that the proposed resonator was qualified to construct trace gas detection sensors

Multifocal PEComa (PEComatosis) of the female genital tract and pelvis: a case report and review of the literature

Perivascular epithelioid cells (PECs) are constantly present in a group of tumors called PEComas, including angiomyolipoma (AML), clear-cell "sugar" tumor (CCST) of the lung and extrapulmonary sites, lymphangioleiomyomatosis, clear-cell myomelanocytic tumor of the falciform ligament/ligamentum teres and rare clear-cell tumors of other anatomic sites. PECs have distinctive morphologic, immunohistochemical, ultrastructural and genetic characteristics, including an epithelioid appearance with a clear to granular cytoplasm, a round to oval, centrally located nucleus, and an inconspicuous nucleolus. PECs also express melanocytic and myogenic markers like HMB45 and smooth muscle actin. PEComa is rare in human, and multifocal PEComas (PEComatosis) is extremely rare. Up to now there have been only less than 5 cases described in the literature. Here we report a 46-year old Chinese woman who had PEComatosis arising from the genital tract and pelvis. To our knowledge, this is the first case of PEComatosis ever reported in China

Microscopic Investigation of a Copper Molten Mark by Optical Microscopy (OM) and Atomic Force Microscopy (AFM)

AbstractA wide variety of physical and chemical detecting methods have been proposed for discriminating between and electric arc bead that caused a fire, versus one that was caused by the fire itself. The simplest proposed method claims that examination of the molten marks in a bead under a microscope will suffice to make the distinction. Generally, copper molten marks of the bead are examined by using optical (OM) and scanning electron microscopy (SEM). In this paper, OM and AFM were employed to investigate a molten mark formed in laboratory. AFM observation reveals that AFM could be an auxiliary method to investigate the copper molten mark formed in the fire in order to confirm the reasons of the fire