scholarly journals Protective Ag:TiO2 thin films for pressure sensors in orthopedic prosthesis: the importance of composition, structural and morphological features on the biological response of the coatings

2014 ◽  
Vol 25 (9) ◽  
pp. 2069-2081 ◽  
Author(s):  
C. Lopes ◽  
P. Fonseca ◽  
T. Matamá ◽  
A. Gomes ◽  
C. Louro ◽  
...  
Keyword(s):  
Thin Films ◽  
Pressure Sensors ◽  
Biological Response ◽  
Morphological Features ◽  
Orthopedic Prosthesis

scholarly journals Cylinder pressure sensors for smart combustion control

2019 ◽  
Vol 8 (1) ◽  
pp. 75-85 ◽  
Author(s):  
Dennis Vollberg ◽  
Dennis Wachter ◽  
Thomas Kuberczyk ◽  
Günter Schultes
Keyword(s):  
Thin Films ◽  
Test Bench ◽  
Copper Wire ◽  
Combustion Process ◽  
Pressure Sensors ◽  
Gauge Factor ◽  
Full Detail ◽  
Relative Pressure ◽  
Cylinder Pressure ◽  
Combustion Control

Abstract. Different sensor concepts for time-resolved cylinder pressure monitoring of combustion engines are realized and evaluated in this paper. We distinguish a non-intrusive form of measurement outside the cylinder, performed by means of a force compression rod from intrusive, real in-cylinder measurement by means of pressure membrane sensors being exposed to the hot combustion process. The force compression rod has the shape of a sine wave with thinner zones equipped with highly sensitive foil strain gauges that experience a relatively moderate temperature level of 120 ∘C. The sensor rod delivers a relative pressure value that may be influenced by neighbour cylinders due to mechanical coupling. For the intrusive sensor type, two different materials for the membrane-type sensor element were simulated and tested, one based on the ceramic zirconia and the other based on stainless steel. Due to the higher thermal conductivity of steel, the element experiences only 200 ∘C while the zirconia element reaches 300 ∘C. Metallic chromium thin films with high strain sensitivity (gauge factor of 15) and high-temperature capability were deposited on the membranes and subsequently structured to a Wheatstone bridge. The pressure evolution can be measured with both types in full detail, comparable to the signals of test bench cylinder pressure sensors. For the preferential steel-based sensor type, a reliable laser-welded electrical connection between the thin films on the membrane and a copper wire was developed. The in-cylinder pressure sensors were tested both on a diesel test bench and on a gas-fired engine. On the latter, an endurance test with 20 million cycles was passed. Reliable cylinder pressure sensors with a minimum of internal components are thus provided. The signals will be processed inside the sensor housing to provide analysis and aggregated data, i.e. mass fraction burned (MFB50) and other parameters as an output to allow for smart combustion control.

Ferroelectric Thin Films in Micro-electromechanical Systems Applications

MRS Bulletin ◽  
1996 ◽  
Vol 21 (7) ◽  
pp. 59-65 ◽  
Author(s):  
D.L. Polla ◽  
L.F. Francis
Keyword(s):  
Thin Films ◽  
Integrated Circuit ◽  
Microelectromechanical Systems ◽  
Pressure Sensors ◽  
Ferroelectric Ceramic ◽  
Consumer Electronics ◽  
Ferroelectric Ceramics ◽  
Control Electronics ◽  
Commercial Applications ◽  
And Control

Ferroelectric ceramic thin films fit naturally into the burgeoning field of microelectromechanical systems (MEMS). Microelectromechanical systems combine traditional Si integrated-circuit (IC) electronics with micromechanical sensing and actuating components. The term MEMS has become synonymous with many types of microfabricated devices such as accelerometers, infrared detectors, flow meters, pumps, motors, and mechanical components. These devices have lateral dimensions in the range of 10 μm–10 mm. The ultimate goal of MEMS is a self-contained system of interrelated sensing and actuating devices together with signal processing and control electronics on a common substrate, most often Si. Since fabrication involves methods common to the IC industry, MEMS can be mass-produced. Commercial applications for MEMS already span biomedical (e.g., blood-pressure sensors), manufacturing (e.g., microflow controllers), information processing (e.g., displays), and automotive (e.g., accelerometers) industries. More applications are projected in consumer electronics, manufacturing control, communications, and aerospace. Materials for MEMS include traditional microelectronic materials (e.g., Si, SiO2, Si3N4, polyimide, Pt, Al) as well as nontraditional ones (e.g., ferroelectric ceramics, shapememory alloys, chemical-sensing materials). The superior piezoelectric and pyroelectric properties of ferroelectric ceramics make them ideal materials for microactuators and microsensors.

The Effects of Additive Manufacturing and Electric Poling Techniques on PVdF Thin Films: Towards 3D Printed Functional Materials

2020 ◽  
Author(s):  
Jinsheng Fan ◽  
David Gonzalez ◽  
Jose Garcia ◽  
Brittany Newell ◽  
Robert A. Nawrocki
Keyword(s):  
Thin Films ◽  
Smart Materials ◽  
Vinylidene Fluoride ◽  
Pressure Sensors ◽  
Functional Materials ◽  
Piezoelectric Constant ◽  
Β Phase ◽  
Calibration Curves ◽  
Wide Range ◽  
3D Printed

Abstract Mechanical flexibility, faster processing, lower fabrication cost and biocompatibility enable poly (vinylidene fluoride) (PVdF) to have a wide range of applications. This work investigated the use of a piezoelectric polymeric material, PVdF, in combination with 3D printing, to explore new strategies for the fabrication of smart materials with embedded functions, namely sensing. The motivation behind this research was to design and fabricate PVdF thin films that will be used to build pressure sensors with applications in active intelligent structures. In this work, 3D printed PVdF thin films with thickness values in the range of 250 to 350 μm were poled under high direct current electrical fields, which were varied from 0.4 to 12 MV/m and temperatures from 80 to 140 °C. Copper electrodes were applied, forming a standard capacitor layered structure, to facilitate poling and to collect piezoelectric output voltage. The poling process enabled the piezoelectric crystalline phase transition of printed PVdF films to transfer from the non-active a α-phase to the piezoelectric active β-phase and rearranged the dipole alignments of the β-phase. The efficiency of poling was evaluated through the piezoelectric constant calculated from measured calibration curves. These calibration curves demonstrated the PVdF sensing device have a positive linear correlation between mechanical input and voltage output. We found that a peak value in piezoelectric constant correlated with poling voltages and temperatures. The highest piezoelectric constant achieved through contact poling was 32.29 pC/N poled at 750 V and 120 °C, and temperature was deemed the most important factors to influence piezoelectric constant. We believe that the present work demonstrates a path towards fully 3D printed smart, functional materials.

Development and Characterization of PVDF Thin Films for pressure sensors

2018 ◽  
Vol 5 (10) ◽  
pp. 21082-21090 ◽  
Author(s):  
T.S. Roopaa ◽  
H.N. Narasimha Murthy ◽  
V.V. Praveen Kumar ◽  
M. Krishna
Keyword(s):  
Thin Films ◽  
Pressure Sensors

Some electronic properties and morphological features of hybrid material DNA–SWCNT thin films

2010 ◽  
Vol 150 (33-34) ◽  
pp. 1584-1586 ◽  
Author(s):  
Yusei Maruyama ◽  
Satoru Motohashi ◽  
Masayuki Tanaka ◽  
Hironori Ogata ◽  
Biao Zhou ◽  
...  
Keyword(s):  
Thin Films ◽  
Electronic Properties ◽  
Hybrid Material ◽  
Morphological Features

scholarly journals Materials of Nanocrystalline Sr1-xBaxBi4Ti4O15 for Piezoelectric Sensor

2008 ◽  
Vol 55-57 ◽  
pp. 253-256 ◽  
Author(s):  
N. A. A. Manaf ◽  
Muhamad Mat Salleh ◽  
Muhammad Yahaya
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Pressure Sensors ◽  
Piezoelectric Sensor ◽  
Titanium Butoxide ◽  
Loading Method ◽  
Different Temperatures ◽  
Dielectric Constant Measurement ◽  
Crystalline Nature ◽  
Source Materials

The nanocrystalline Strontium Barium Bismuth Titanate (SBBT) thin films with structure of Al/TiO2/SBBT/TiO2/RuO2/SiO2/Si were fabricated using sol-gel technique. The source materials are bismuth acetate Bi(CH3COO)2, barium acetate Bi(CH3COO)2, strontium acetate Sr(CH3COO)2 and titanium butoxide (Ti(OC4H9 )4). Different nanostructures of the films were prepared with un-annealed condition as well as after annealing at three different temperatures of 400, 500 and 6000C, in air for 2 minutes. The structure of SBBT thin films have been systematically studied by XRD, AFM, SEM and dielectric constant measurement. For the sensor device measurement, the SBBT thin film pressure sensors were tested by pneumatic loading method at pressure range between 0 to 450 kPa. It was found that the sensing properties of the films were affected by the crystalline nature of the films. It is shown that there is a linear relationship between the crystallization, grains size and dielectric properties with the sensing response of the film towards pressure.

Relationships between the solution and solid-state properties of solution-cast low-k silica thin films

2016 ◽  
Vol 18 (30) ◽  
pp. 20371-20380 ◽  
Author(s):  
Chao-Ching Chiang ◽  
Chien-You Su ◽  
An-Chih Yang ◽  
Ting-Yu Wang ◽  
Wen-Ya Lee ◽  
...  
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Physical Properties ◽  
Amorphous Silica ◽  
Morphological Features ◽  
Silica Thin Films ◽  
Different Types ◽  
Solution Cast ◽  
Low K

This paper reports on the fabrication of low-k (amorphous) silica thin films cast from solutions without and with two different types of surfactants (TWEEN® 80 and Triton™ X-100) to elucidate the relationships between the structural/morphological features of the casting solutions and the physical properties of the resulting thin films.

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