Search results for: Thomas Walewyns
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The formaldehyde detection is important for protecting human health and controlling environment pollution. Many metal oxide sensors have been developed for the formaldehyde detection in the last decade. The NiO sensor is considered as the most sensitive one, which is able to detect very low concentration of formaldehyde (< 1 ppm). But it needs a high operating temperature. Presently, graphene has...
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In this live demonstration, we present the microsystem integration of a palladium-based MEMS capacitive hydrogen gas sensor and its sub-components. The system includes all the elements of the data acquisition chain. The MEMS device is interfaced by a capacitance-to-digital converter for signal conditioning, and a microcontroller associated to a radio for both data processing and transmitting. Moreover...
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2015 IEEE SENSORS > 1 - 4
We developed and integrated a MEMS capacitive transducer based on aluminium/palladium bimorph configured as clamped-clamped beams, performing fast and highly selective hydrogen detection. The bimorph is obtained by combining evaporation and sputtering deposition techniques and acts as actuator of the structure. The stress control in the beams has been investigated in order to gain control over the...
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Procedia Engineering > 2014 > 87 > Complete > 268-271
We developed an ultra-low power MEMS hydrogen (H2) sensor performing high dynamics together with high sensitivity up to the Lower Explosive Limit (LEL), i.e. 4% vol. H2 in dry air. The architecture consists of Al clamped-clamped beams (700 nm- thick, 800μm-total width, 140 or 240μm-length) with both ends made of a Pd/Al bimorph (200/700 nm-thick) on a quarter of its length, acting as actuators, released...
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We have proposed and demonstrated a novel sequence in MEMS fabrication process flow. The novel MEMS fabrication process flow can be shortly described as a “packaging first, MEMS release second”, whereas a standard process starts form MEMS release and ends up with packaging. The process is explored on a 3D capacitive MEMS sensor (3 × 3 mm2). Unreleased wafer is singulated by sawing on individual dies,...
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2012 IEEE Sensors > 1 - 4
We present and model a miniaturized field ionization sensor associated with a MEMS actuation system. The sensor consists in parallel plates spaced by a few micrometers and metal nanowires added to one of the electrodes in order to enhance the electric field. A split bottom electrode is used to differentiate between the ionization field monitoring and the electrostatically-actuated gap spacing. Such...
