Among many coherent optical methods one should distinguished Grating Interferometry (GI) which allows accurate
in-plane displacement measurements and Digital Speckle Pattern Interferometry (DSPI) used for in-plane and
out-of-plane measurements. Development of sensors based on both methods mentioned above as complementary ones
will provide user universal group of sensors from which depending on measurement requirements such as measuring
range, object surface profile and measurement conditions the most appropriate can be chosen.
In-plane displacement measurements are of interested of different branches of industry - from micro (i.e.:
characterization of MEMS or MOEMS) to civil engineering (i.e.: Structural Health Monitoring systems). In the paper the
new optical coherent sensor for in-plane displacement and strain measurements is presented. The sensor combines GI
and DSPI methods in one device which can be used for testing of objects with different types of surfaces. GI requires the
specimen grating attached at the surface but provides very good measurement accuracy however DSPI can be applied for
testing of objects with rough surfaces but due to higher noise gives lower accuracy. The sensor can work in three modes:
as GI only, DSPI only and both GI and DSPI simultaneously. The third mode can by useful when the specimen grating
is attached on the part of object under test only.
In the paper the theoretical background of the sensor is presented. For confirmation of GI/DSPI sensor possibilities
the specially designed demonstrator is described and the exemplary results obtained during its laboratory tests are shown.
Successful application of proposed sensor is possible due to its miniaturization, simplicity of operation by user
(compact structure and automation of measurement procedure) and low cost. The last mentioned condition will
be possible due to low cost replication techniques with usage of silicon technology.
We describe the fabrication of wafer-scale alkali vapor cells based on silicon micromachining and anodic bonding. The principle of the proposed micromachined alkali cell is based on an extremely compact sealed vacuum cavity of a few cubic millimeters containing caesium vapors, illuminated by a high-frequency modulated laser beam. The alkali cells are formed by sealing an etched silicon wafer between two glass wafers. The technique of cell filling involves the use of an alkali dispenser. The activation of cesium vapors is made by local heating of the dispenser below temperature range causing degradations of cesium vapor purity. Thus, the procedure avoids negative effects of cesium chemistry on the quality of cell surfaces and sealing procedure. To demonstrate the clock operation, cesium absorption as well as coherent population trapping resonance was measured in the cells.
In the paper the new concept of fully integrated scanning confocal optical microscope on-chip is proposed. The operation of this microscope combines the 3-D transmissive scanning of VCSEL laser beam by use of two MOEMS scanners, and active signal detection, based on the optical feedback in the VCSEL laser cavity. The silicon-based electrostatically driven scanners provide controlled movement of two convex microlenses, working as an objective lens of microscope. Glass microlenses are monolithically integrated on movable silicon tables of scanners. The first results of technological investigation on the microscope components are presented.
A new concept of the fabrication process for glass microlenses (external diameter ED<1 mm, focal length a few millimeters), based on the silicon master mask-less anisotropic wet etching in KOH, vacuum anodic bonding and re-flow of borosilicate glass, followed by the precise wafer-scale polishing and DRIE has been presented. A single spherical microlens as well as an array of spherical microlenses with focal length between 44.8 and 8.6 mm and external diameter 0.35 to 0.985 mm have been repeatable manufactured.
Microfluidic detectors have been designed for μ-TAS application. Micromechanical, integrated silicon-glass nanolitres range conductivity and fluorescence detectors have been presented. The construction, technology, and basic characteristics have been discussed for the first time in Poland.
The paper presents fire and gas hazards occurring in underground hard coal mines; methods of hazard detection and methods of gas concentration measurement used while monitoring and/or mine rescue operations. Chromatographs applied to measurement of atmosphere in mine underground and construction of the own-design gas chromatograph; functional examination of the microchromatograph and analyses of gas mixtures are discussed.
A new microwave enhanced anisotropic wet method of etching of silicon (External Etching Microwave Silicon - E2Msi), has been presented. In the method an etchant is irradiated by microwave and then flows to an external reaction chamber where etching is performed. The reaction chamber is situated outside of area of microwave irradiation. The main characteristics of E2Msi etching has been presented. It has been shown that the new process utilizes a memory effect of high chemical reactivity observed in water and water-based solution irradiated by microwave.
LTCC package of silicon membrane katharometer was made and investigated. The package protects the katharometer against mechanical damage and makes possible an easy connection of electrical signals. Moreover, the heater and temperature sensors allow for obtaining the proper temperature of the element. The basic electrical parameters of the integrated heater and thermistors as well as measured temperature distribution are presented.
The paper describes the microsystems for total chemical analysis and the structure of a gas microchromatograph. The construction and technical data of capillary micro column of thermo conducting detector and gas microvalve are also described. The paper refers to the test of a model of gas micro chromatography, the analyses of gas samples and presents the exemplary chromatograms.
Under etching of convex corners during the fabrication process of pressure sensor with the 'bossed' type structure seriously deteriorates parameters of these devices. The problem can be solved by application of properly designed masks with compensating corners.
A gas analyzer based on chromatography method using silicon- glass components has been built. Its main components were made by using MAMS-like technology, and its conception is concurrent to the idea of an integrated silicon chromatography proposed by SC Terry.
In the article, the results of investigation of the silicon microtips manufacturing process are presented. A two-stage technology of the microtips forming has been worked out. At the first stage, a single-micrometer high, suitably shaped precursor of the tip is done. Next, the process of its sharpening is performed, using the isotropic etching and thermal oxidation techniques. The arrays of the reproducible silicon microtips were fabricated.
Computer calculations of electric field distribution in VLEDs and FETRODEs with cylindrical and prismatoidal geometry are presented. Plasma etched prismatoidal silicon tips are shown. A new TV flat screen with FETRODEs (or VLEDs) has been proposed.