Electro-Mechanical Coupling and Power Generation in a Pzt Micro-Engine

2001 ◽  
Vol 687 ◽  
Author(s):  
D.F. Bahr ◽  
K.R. Bruce ◽  
B.W. Olson ◽  
L.M. Eakins ◽  
C.D. Richards ◽  
...  

AbstractA piezoelectric thin film MEMS device for generating power from a novel heat engine which approaches a Carnot cycle has been developed. The structure of the underlying electrode and PZT thin film generator has been optimized for increased adhesion. Atomic force microscopy was used to track electrode grain size and roughness; generating grain sizes of approximately 100 and 200 nm in diameter and a roughness of about 14-20 nm provide substantial improvements in film adhesion over systems with smaller grains and smoother surfaces. This has led to the ability to operate the engine at frequencies between 10 and 1500 Hz. The system of interest (a fluid filled cavity sealed by a micromachined silicon membrane and the PZT film) shows increased deflections for a given pressure applied to the membrane at frequencies where the system resonates. By operating the system dynamically, it is possible to generate more than 2 V from a single generator structure.

Author(s):  
Pankaj B. Kaul ◽  
Vikas Prakash

Thin films in general exhibit different thermal properties compared to bulk due to size effect [1–3]. In this study, the thermal conductivity of sputtered Sn films of thickness 500 nm ± 50 nm and 100 nm ± 20 nm are obtained from 55K to 300K and from 40K to 310K, respectively, using the three omega method. The thermal conductivity of 500 nm thin film at room temperature is 46.2 ±4.2 W/m-K, which is lower when compared to its bulk value of 63 W/m-K, and increases gradually as the temperature is lowered to 55K. In contrast, the thermal conductivity of the 100 nm thin film exhibits even reduced thermal conductivity, 36 ± 2.88 W/m-K at 300K, when compared to the 500 nm film, and decreases as the temperature is lowered. The reduction in thermal conductivity of Sn thin film may be due to the pronounced effects of electron scattering at the grain boundaries as well as the twin boundaries in addition to the scattering from the boundary surface at lower temperatures. These experimentally determined thermal conductivities are compared to models that take into account size effects on thermal conductivity of metallic films based on electronic scattering as proposed by Fuchs-Sondheimer (FS), Mayadas-Shatzkes (MS) and Qiu and Tien (QT). The experimentally measured thermal conductivity of Sn films is in good agreement with the MS model indicating the importance of the grain boundary scattering. Thickness measurements are obtained by ellipsometry and profilometer. The estimation of the mean grain size in both films and the evidence of twin boundaries are obtained by Atomic Force Microscopy.


2011 ◽  
Vol 14 (8) ◽  
pp. H311 ◽  
Author(s):  
J. Y. Son ◽  
D.-Y. Kim ◽  
H. Kim ◽  
W. J. Maeng ◽  
Y.-S. Shin ◽  
...  

2021 ◽  
Vol 900 ◽  
pp. 103-111
Author(s):  
Christelle Habis ◽  
Jean Zaraket ◽  
Michel Aillerie

Transparent conductive oxides are materials combining great transparency with high conductivity. In photovoltaic applications, they are developed under thin layer for the realization of upper electrodes of solar cells. Among transparent oxide materials, Zinc Oxide (ZnO) presents unique properties, starting with its first qualities to be abundant, low-cost and non-toxic oxide. Zinc Oxide thin film was deposited on rectangular glass substrate by magnetron sputtering. After an overview of the properties expected for good transparent conductive materials, the effect of distance from the center of the cell on the morphology of the film was investigated by Atomic Force Microscopy (AFM). The scanning was done on different area of the sample as function of the distance from the central position of the direct sputtering jet. As far as the distance increased, it has been noticed a quasi-linear increase in thickness of the ZnO deposited film and a change in the grain shape from spherical to pyramidal with an increase in the size of the particles. Controlling the sputtering distance allows the control of texture, thus of the Haze factor, the photo-generation of excitons, as well the optical transmission of the TCO layer and finally an improvement in the efficiency of the so-built photovoltaic cells.


2006 ◽  
Vol 20 (02) ◽  
pp. 217-231 ◽  
Author(s):  
MUHAMMAD MAQBOOL ◽  
TAHIRZEB KHAN

Thin films of pure silver were deposited on glass substrate by thermal evaporation process at room temperature. Surface characterization of the films was performed using X-ray diffraction (XRD) and atomic force microscopy (AFM). Thickness of the films varied between 20 nm and 72.8 nm. XRD analysis provided a sharp peak at 38.75° from silver. These results indicated that the films deposited on glass substrates at room temperature are crystalline. Three-dimension and top view pictures of the films were obtained by AFM to study the grain size and its dependency on various factors. Average grain size increased with the thickness of the deposited films. A minimum grain size of 8 nm was obtained for 20 nm thick films, reaching 41.9 nm when the film size reaches 60 nm. Grain size was calculated from the information provided by the XRD spectrum and averaging method. We could not find any sequential variation in the grain size with the growth rate.


Author(s):  
Shunyu Chang ◽  
Yanquan Geng ◽  
Yongda Yan

AbstractAs one of the most widely used nanofabrication methods, the atomic force microscopy (AFM) tip-based nanomachining technique offers important advantages, including nanoscale manipulation accuracy, low maintenance cost, and flexible experimental operation. This technique has been applied to one-, two-, and even three-dimensional nanomachining patterns on thin films made of polymers, metals, and two-dimensional materials. These structures are widely used in the fields of nanooptics, nanoelectronics, data storage, super lubrication, and so forth. Moreover, they are believed to have a wide application in other fields, and their possible industrialization may be realized in the future. In this work, the current state of the research into the use of the AFM tip-based nanomachining method in thin-film machining is presented. First, the state of the structures machined on thin films is reviewed according to the type of thin-film materials (i.e., polymers, metals, and two-dimensional materials). Second, the related applications of tip-based nanomachining to film machining are presented. Finally, the current situation of this area and its potential development direction are discussed. This review is expected to enrich the understanding of the research status of the use of the tip-based nanomachining method in thin-film machining and ultimately broaden its application.


2017 ◽  
Vol 49 (1) ◽  
pp. 73-79
Author(s):  
Jelena Potocnik ◽  
Milos Nenadovic ◽  
Bojan Jokic ◽  
Maja Popovic ◽  
Zlatko Rakocevic

In this work, Glancing Angle Deposition technique was used for obtaining nanostructured nickel thin film with vertical posts on glass substrate which was positioned 75 degrees with respect to the substrate normal and rotated with a suitable constant speed. The obtained nickel thin film was characterized by Scanning Electron Microscopy, Atomic Force Microscopy and X-ray Photoelectron Spectroscopy. It was found that the deposited thin film consists of 94.0 at.% of nickel. Magnetic properties of the deposited thin film were determined by Magneto-Optical Kerr Effect Microscopy. According to the obtained coercivity values, it can be concluded that the nickel thin film shows uniaxial magnetic anisotropy.


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