Netherlands
Netherlands

Time filter

Source Type

Iervolino E.,Xensor Integration | Iervolino E.,elft University | Van Herwaarden A.W.,Xensor Integration | Van Herwaarden F.G.,Xensor Integration | And 5 more authors.
Thermochimica Acta | Year: 2011

This paper reports on the temperature calibration and electrical characterization of the calorimeter chip UFS1 (internal design XI-400) developed for the new commercially available differential scanning calorimeter (DSC), the Flash DSC 1 of Mettler-Toledo. The chip consists of 2 identical membranes both with a p-type polysilicon microheater in the center of the membrane and a p/n-type polysilicon thermopile for measuring the sample temperature. The temperature calibration of the XI-400 is performed in the temperature range from 208 K to 723 K. An isothermal calibration is first performed to calibrate the heater resistance and the obtained curve is used to calibrate the integrated thermopile. The accuracy of the calibration is then determined by measuring the extrapolated onset temperature (Te) of primary standards. A detailed electrical characterization of the device is also reported. The calibration method implemented and the good temperature reproducibility of the device allow to use devices with uncalibrated heater resistance in the temperature range from 208 K to 723 K with a typical maximum error of ±5 K. © 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.


Santagata F.,Technical University of Delft | Creemer J.F.,Technical University of Delft | Iervolino E.,Xensor Integration | Mele L.,Technical University of Delft | And 2 more authors.
Journal of Microelectromechanical Systems | Year: 2011

We present a micromachined Pirani gauge that combines low detection limit and strongly reduced footprint. It consists of a tube-shaped resistor that is buried in the silicon substrate. The choice of the tube geometry gives the resistor a very high structural rigidity. This enables the fabrication of much longer resistors, thus shifting the detection limit toward lower pressures. In addition, since the resistor is buried under the silicon surface, its footprint is kept very small. The high stiffness allowed the fabrication of a 3-mm-long and 1.8-\mum}-thick poly-Si tube with a 1-mumgap without buckling and/or stiction problems. It shows a detection limit of 0.1 Pa for a noise level of 50 muV, and it has a footprint of only 0.012 mm2. This is an improvement of at least 20 times compared with Pirani gauges with the same detection limit. Pirani tubes of 1.6- and 0.4-mm lengths have also been designed, fabricated, and tested. The 0.4-mm-long tube shows a low pressure limit of 2 Pa, whereas the tube of 1.6 mm shows a low pressure limit of 0.2 Pa. The measured transfer functions correspond very well to the 1-D analytical model. © 2011 IEEE.


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.


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

We present a fluidic micro-calorimeter that shows high versatility measuring both thermal properties of samples and enthalpies of bio-chemical processes. The micro-calorimeter consists of two stacked chips with silicon nitride membranes that define the liquid chamber of 2.6 μl. The chamber has two inlets which allow real time reactions monitoring. We measured the thermal conductivity and diffusivity of water-methanol solutions with 1% resolution, and we determined the mixing enthalpy for watermethanol system with a signal/ noise ratio of 20.


Splinter R.,Xensor Integration | van Herwaarden A.W.,Xensor Integration | van Wetten I.A.,Xensor Integration | Pfreundt A.,Technical University of Denmark | Svendsen W.E.,Technical University of Denmark
Thermochimica Acta | Year: 2014

Based on a modified version of standard chips for fast differential scanning calorimetry, DSC of liquid samples has been performed at temperature scan rates of up to 1000. °C/s. This paper describes experimental results with the protein lysozyme, bovine serum, and olive oil. The heating and cooling rate of the sensor is measured for temperature scan rates of up to 1300. °C/s with water and 2-butanol, in the temperature range of -90. °C/s to +130. °C/s. The lysozyme is measured at temperature scan rates varying from 10. °C/s to 400. °C/s and in concentrations between 0.1% and 10% protein by weight. The bovine serum measurements show two main peaks, in good agreement with standard DSC measurements. Olive oil has been measured, with good agreement for the cooling curve and qualitative agreement for the heater curve, compared to DSC measurements. © 2014 Elsevier B.V.


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 Wetten I.A.,Xensor Integration | Van Wetten I.A.,Wageningen University | Van Herwaarden A.W.,Xensor Integration | Splinter R.,Xensor Integration | And 2 more authors.
Thermochimica Acta | Year: 2015

Extra virgin olive oil (EVOO) is an economically valuable product, due to its high quality and premium price. Therefore it is vulnerable for adulteration by means of the addition of cheaper vegetable oils. Differential scanning calorimetry (DSC) has been suggested as a fast technique for the detection of adulteration. However, measurements still take several hours. Fast DSC measurements take several minutes. Therefore this study investigates the applicability of fast DSC for the detection of sunflower oil (SFO) in EVOO. Nine EVOOs, five SFOs and three mixtures were analysed. Cooling curves of EVOO and SFO show one major exothermic peak. Because the cooling curves of EVOO and SFO are very similar they cannot be used for the detection of adulteration. Heating curves of EVOOs show two major endothermic peaks after slow cooling (-2 °C/s), heating curves of SFOs only one. Addition of SFO to EVOO caused a rapid decrease in the coldest endothermic peak and can therefore be used in the detection of adulteration of EVOO by SFO. Depending on the type of olive oil, the presence of 2-10% SFO can already be detected. © 2014 Elsevier B.V.

Loading Xensor Integration collaborators
Loading Xensor Integration collaborators