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Van Herwaarden S.,Xensor Integration
Procedia Engineering | Year: 2010

Xensor Integration has been active in development and production of micro-sensors for customers since more than 2 decades. In that time we have developed products for applications in areas such as space, agriculture, medical and laboratory equipment. In this paper we will briefly discuss some research and development projects we carried out in that time, and then zoom in on an example of such a project, the development of the Flash DSC of Mettler-Toledo. This will give an impression of how unpredictable research and innovation really are. And how projects for space, medical and laboratory applications each have their own specifics.

Mele L.,Technical University of Delft | Santagata F.,Technical University of Delft | Iervolino E.,Xensor Integration | Mihailovic M.,Technical University of Delft | And 5 more authors.
Sensors and Actuators, A: Physical | Year: 2012

This paper presents a fabrication process for high-temperature MEMS microhotplates that uses sputtered molybdenum as a conductive material. Molybdenum has a high melting point (2693 °C, bulk) and is simpler to deposit and pattern in larger series than platinum. Molybdenum is sensitive to oxidation above 300°C, so during fabrication it is protected by PECVD silicon oxide. The electrical resistivity is linear with the temperature up to 700°C at least. Molybdenum microhotplate has a higher maximum operating temperature than platinum which is demonstrated by the observation of the boiling of barium carbonate (BaCO3) microcrystals at 1360°C. Annealing at 1100°C is effective in extending the operating range. The molybdenum microhotplate performs far better than platinum also in terms of long-term resistance drift. The material properties of the sputtered molybdenum are studied and the overall performances of the microhotplate are tested, with regard to power consumption, temperature uniformity and dynamic behavior. © 2011 Elsevier B.V. All rights reserved.

Van Herwaarden S.,Xensor Integration | Iervolino E.,Xensor Integration | Iervolino E.,Technical University of Delft | Van Herwaarden F.,Xensor Integration | And 3 more authors.
Thermochimica Acta | Year: 2011

This paper presents a new twin-membrane calorimeter chip for fast differential scanning calorimetry (DSC) with the Flash DSC 1 of Mettler-Toledo. The thin silicon nitride membranes enable scan rates in excess of 10 kK/s in heating and up to 4 kK/s in cooling for sample masses between 100 ng and 10 μg in the temperature range of -100 °C to 450 °C. The time constant for cooling is about 12 ms, the power resolution is typically 0.1-0.5 μW, the temperature accuracy of non-calibrated chips is typically better than ±5 K. The paper also shows measurements for the scan-rate dependent thermal lag of the device, showing an empty sensor thermal lag of about 0.2 ms, and a mass dependent thermal lag of about 0.3 ms/μg for Indium for a good thermal contact between Indium and membrane. © 2011 Elsevier B.V. All rights reserved.

Mathot V.,SciTe | Pyda M.,SciTe | Pyda M.,Poznan University of Medical Sciences | Pyda M.,Rzeszow University of Technology | And 6 more authors.
Thermochimica Acta | Year: 2011

The performance of the Flash DSC 1, a recently introduced, commercial available chip fast scanning calorimeter (FSC) based on MEMS sensor technology, was studied. Topics included calibration; symmetry; repeatability; scan rate control windows of operation. Scan rates up to 20 000 °C/s for empty cell measurements in cooling and heating have been achieved. By combinations of scan rates up to 1000 °C/s various topics in between -95 to 450 °C were studied on polymers including self nucleation; annealing and thermal fractionation; 'hot' and 'cold' crystallization; amorphization; and cross-over of crystallization behavior with scan rate variation for two polymers. Sample masses around 1 μg and less gave good results with excellent repeatability and acceptable thermal lags. The Flash DSC 1 enables to mimic realistic conditions of practice and to measure (meta)stability and reorganization phenomena of substances and materials, including polymers, metals, pharmaceuticals etc. © 2011 Elsevier B.V. All rights reserved.

Iervolino E.,Xensor Integration | Van Herwaarden A.W.,Xensor Integration | Van Der Vlist W.,Technical University of Delft | Sarro P.M.,Technical University of Delft
Journal of Microelectromechanical Systems | Year: 2011

This paper presents a microelectromechanical-systems device for thermogravimetric analysis (TGA) with integrated thermal actuators. It consists of a sensing cantilever paddle connected to two separated thermal actuators, one at each side of the cantilever. An integrated thermocouple allows to measure directly the temperature difference between the heater at the tip of the cantilever paddle and the device silicon frame. The cantilever paddle vibration amplitude (frequency) is measured with an integrated piezoresistor. The temperature dependence of the resonance frequency on local heating with the integrated heater is investigated. Mass and temperature calibrations are performed from 0 to 6 ng and from 300 K to 823 K, respectively. To demonstrate the device performance, TGA of polyamide 6 and paraffin samples is carried out. TGA can be performed with the presented device in the temperature range from 298 K up to 920 K for sample masses as small as 0.8 ng. The mass sensitivity is about 164 Hz/ng at ambient temperature. © 2006 IEEE.

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