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1.
This paper reports on a method for the investigation of mechanical stress on MEMS sensor and actuator structures due to packaging
processes. A silicon test chip is developed and manufactured to validate the simulation results. Finite element analysis (FEA)
is used to optimize the geometric parameters and to find a stress sensitive sensor geometry. A diaphragm structure is used
as mechanical amplifier for bulk induced stresses during the packaging process. Piezo resistive solid state resistors are
doped into the surface of the chip to measure the stress in the diaphragms and at the contact pads being most significant
locations for analysis. A high precision ohmmeter was used to measure the resistance prior and past the packaging process.
The captured data allows for computation of the resulting stress loads in magnitude. Therefore, a stress evaluation of different
packaging technologies is conducted and the impact of the packaging process on reliability can be estimated immediately. 相似文献
2.
A governing equation was developed to predict the density ρ(org) of organic material composed of carbon, oxygen, and hydrogen using the elemental ratios O:C and H:C as input parameters: ρ(org) = 1000 [(12 + 1(H:C) + 16(O:C)]/[7.0 + 5.0(H:C) + 4.15(O:C)] valid for 750 < ρ(org) < 1900 kg m(-3). Comparison of the actual to predicted ρ(org) values shows that the developed equation has an accuracy of 12% for more than 90% of the 31 atmospherically relevant compounds used in the training set. The equation was further validated for secondary organic material (SOM) produced by isoprene photo-oxidation and by α-pinene ozonolysis. Depending on the conditions of SOM production, ρ(org/SOM) ranged from 1230 to 1460 kg m(-3), O:C ranged from 0.38 to 0.72, and H:C ranged from 1.40 to 1.86. Atmospheric chemistry models that simulate particle production and growth can employ the developed equation to simulate particle physical properties. The equation can also extend atmospheric measurements presented as van Krevelen diagrams to include estimates of the material density of particles and their components. Use of the equation, however, is restricted to particle components having negligible quantities of additional elements, most notably nitrogen. 相似文献
3.
Soeren Schumacher Thomas Nagel Frieder W. Scheller Nenad Gajovic-Eichelmann 《Electrochimica acta》2011,(19):6607
In addition to the well-established spectroscopic Alizarin Red S (ARS) assay for the determination of binding constants between arylboronic acids and different saccharides, we report the use of ARS as a reporter in an electrochemical set-up. The electrochemical properties of ARS, the binding to phenyl boronic acid (PBA) and the competition with fructose in phosphate buffer at pH 7.4 were investigated by cyclic voltammetry (CV). By choosing a negative scan direction (starting at +0.2 V), a quasi-reversible process was detected at E0′ = −0.59V with ΔEp = 0.1V. An irreversible oxidation peak at +0.42 V could also be detected. These peaks are characterised both as a 2-proton-2-electron transfer and corresponds to the oxidation and reduction of the anthraquinone or the ortho-quinone moiety. After addition of phenylboronic acid a new oxidation peaks occurred at −0.42 V which correlates with the ARS–PBA interaction. The peak current increased with increasing phenylboronic acid concentration according to the release of BA and formation of the ARS–PBA ester. After addition of fructose the peak current decreases again, in proportion to the fructose concentration, enabling the use of ARS as an electrochemical reporter for fructose detection up to 50 mM. Also the interaction with other cis-diol containing compounds such as sorbitol, mannitol, glucose and mannose was investigated and a dependence based on already published binding constants to phenylboronic acid could be shown. 相似文献
4.
Cordtz J Olde B Solem K Ladefoged SD 《Hemodialysis international. International Symposium on Home Hemodialysis》2008,12(3):369-377
Intradialytic hypotension (IDH) is one of the most important short-term complications to hemodialysis (HD). Inadequate cardiac filling due to a reduction in the central blood volume is believed to be a major etiological factor. The aim of this study was to evaluate whether these pathophysiologic events are reflected in the central venous oxygen saturation (ScO(2)) and thoracic admittance (TA) during dialysis. Twenty ambulatory HD patients, 11 hypotension prone (HP) and 9 hypotension resistant, with central vascular access, were monitored during 3 HD sessions each. ScO(2), TA, finger blood pressure (BP), and relative change in blood volume (DeltaBV) were measured and sampled continuously. The relative TA decrease and DeltaBV were both largest in the HP group (p<0.05 for both), whereas ScO(2) decreased only in HP patients (p<0.001). Baseline TA was lower in the HP group (p<0.01). Changes in ScO(2) and TA correlated much closer than did changes in ScO(2) and DeltaBV (r=0.43 and 0.18, respectively). Our results suggest that an intradialytic decrease in cardiac output, as reflected by a fall in ScO(2), is a common feature to HD patients prone to IDH. In patients using a central vascular access, ScO(2) and TA measurements may be more specific to the pathophysiologic events preceding IDH than DeltaBV-the current standard monitoring method. 相似文献
5.
Erkka Saukko Soeren Zorn Mikinori Kuwata Jorma Keskinen Annele Virtanen 《Aerosol science and technology》2013,47(7):531-537
The phase state of secondary organic aerosol (SOA) has an impact on its lifetime, composition, and its interaction with water. To better understand the effect of phase state of SOA on climate interactions, we studied the SOA phase state and the effect of its history and report here the phase state and the humidity-induced phase hysteresis of multicomponent-seeded SOA particles produced in a large, continuously stirred tank reactor. We determined the phase state of the particles by their bounced fraction impacting on a smooth substrate in a low-pressure impactor. The particles were composed of ammonium sulfate ([NH4]2SO4) seed and a secondary organic matter (SOM) shell formed from oxidized α-pinene or isoprene. The ammonium sulfate (AS) seed dominated the deliquescence of the α-pinene SOM multicomponent particles, whereas their efflorescence was strongly attenuated by the SOM coating. Particles coated with isoprene SOM showed continuous phase transitions with a lesser effect by the AS seed. The results agree with and independently corroborate contemporary research.Copyright 2015 American Association for Aerosol Research 相似文献
6.
Pawel E. Malinowski Atsushi Nakamura Dimitri Janssen Yoshitaka Kamochi Ichiro Koyama Yu Iwai Anna Stefaniuk Ewelina Wilenska Caterin Salas Redondo David Cheyns Soeren Steudel Paul Heremans 《Organic Electronics》2014,15(10):2355-2359
We report on the fabrication of organic photodetectors (OPD) based on isolated islands of P3HT:PCBM. Pattern transfer to the active material was done with photolithography based on non-fluorinated solvents and the excessive organic semiconductor was removed with oxygen plasma reactive ion etching. The photoresist system used was found to be benign to the P3HT:PCBM layer as confirmed by absorption, thickness and roughness measurements. Current–voltage characteristics and external quantum efficiency (EQE) remained unchanged after the patterning process. It was demonstrated that it is possible to photolithographically pattern isolated islands with 200 μm edge length with the same dark current density (<10−5 A/cm2 at −2 V bias voltage) and photocurrent density (>5 × 10−3 A/cm2 at −2 V). Furthermore, concerning the solar cell performance, the patterned, small-area devices showed power conversion efficiency of 2.1% and fill-factor of 60%. Dark current was observed to depend on the size of the remaining semiconductor island, which was demonstrated on OPDs with diameter of 50 μm. The presented results show the feasibility of fabrication of isolated devices based on organic semiconductors patterned with non-fluorinated photolithography. 相似文献
7.
Power saving through state retention in IGZO‐TFT AMOLED displays for wearable applications
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Soeren Steudel Jan‐Laurens P.J. van der Steen Manoj Nag Tung Huei Ke Steve Smout Thijs Bel Karin van Diesen Gerard de Haas Joris Maas Joris de Riet Madelon Rovers Roy Verbeek Yen‐Yu Huang Shin‐Chuan Chiang Marc Ameys Florian De Roose Wim Dehaene Jan Genoe Paul Heremans Gerwin Gelinck Auke Jisk Kronemeijer 《Journal of the Society for Information Display》2017,25(4):222-228
We present a qHD (960 × 540 with three sub‐pixels) top‐emitting active‐matrix organic light‐emitting diode display with a 340‐ppi resolution using a self‐aligned IGZO thin‐film transistor backplane on polyimide foil with a humidity barrier. The back plane process flow is based on a seven‐layer photolithography process with a CD = 4 μm. We implement a 2T1C pixel engine and use a commercial source driver IC made for low‐temperature polycrystalline silicon. By using an IGZO thin‐film transistor and leveraging the extremely low off current, we can switch off the power to the source and gate driver while maintaining the image unchanged for several minutes. We demonstrate that, depending on the image content, low‐refresh operation yields reduction in power consumption of up to 50% compared with normal (continuous) operation. We show that with the further increase in resolution, the power saving through state retention will be even more significant. 相似文献
8.
Manoj Nag Adrian Chasin Maarten Rockele Soeren Steudel Kris Myny Ajay Bhoolokam Ashutosh Tripathi Bas van der Putten Abhishek Kumar Jan‐Laurens van der Steen Jan Genoe Flora Li Joris Maas Erik van Veenendaal Gerwin Gelinck Paul Heremans 《Journal of the Society for Information Display》2013,21(3):129-136
In this study, the authors report on high‐quality amorphous indium–gallium–zinc oxide thin‐film transistors (TFTs) based on a single‐source dual‐layer concept processed at temperatures down to 150°C. The dual‐layer concept allows the precise control of local charge carrier densities by varying the O2/Ar gas ratio during sputtering for the bottom and top layers. Therefore, extensive annealing steps after the deposition can be avoided. In addition, the dual‐layer concept is more robust against variation of the oxygen flow in the deposition chamber. The charge carrier density in the TFT channel is namely adjusted by varying the thickness of the two layers whereby the oxygen concentration during deposition is switched only between no oxygen for the bottom layer and very high concentration for the top layer. The dual‐layer TFTs are more stable under bias conditions in comparison with single‐layer TFTs processed at low temperatures. Finally, the applicability of this dual‐layer concept in logic circuitry such as 19‐stage ring oscillators and a TFT backplane on polyethylene naphthalate foil containing a quarter video graphics array active‐matrix organic light‐emitting diode display demonstrator is proven. 相似文献
9.
Claudio Girotto Barry P. Rand Soeren Steudel Jan Genoe Paul Heremans 《Organic Electronics》2009,10(4):735-740
We demonstrate a solution-processed top electrode for large area organic electronic devices. A Ag nanoparticle solution is spray-coated directly on top of an inverted bulk-heterojunction organic solar cell through a shadow mask. After sintering the Ag nanoparticle film at 150 °C, a temperature which is compatible with processes on flexible substrates, cells show performances comparable to those of reference devices with evaporated top-contacts. 相似文献
10.
A. A. Fomin M. A. Fomina V. A. Koshuro I. V. Rodionov A. V. Voiko A. M. Zakharevich A. Aman A. Oseev S. Hirsch S. Majcherek 《Technical Physics Letters》2016,42(9):932-935
We have studied the characteristics of the porous microstructure of tantalum coatings obtained by means of electric spark spraying on the surface of commercial grade titanium. It is established that, at an electric spark current within 0.8–2.2 A, a mechanically strong tantalum coating microstructure is formed with an average protrusion size of 5.1–5.4 µm and pore sizes from 3.5 to 9.2 µm. On the nanoscale, a structurally heterogeneous state of coatings has been achieved by subsequent thermal modification at 800–830°C with the aid of high-frequency currents. A metal oxide nanostructure with grain sizes from 40 to 120 nm is formed by short-time (~30 s) thermal modification. The coating hardness reaches 9.5–10.5 GPa at an elastic modulus of 400–550 GPa. 相似文献