Investigation of ferroelectrics using conventional and in situ electron microscopy

1994 ◽  
Vol 52 ◽  
pp. 586-587
Author(s):  
V. Saikumar ◽  
H. M. Chan ◽  
M. P. Harmer
Keyword(s):  
Nonvolatile Memory ◽  
Ferroelectric Materials ◽  
Gate Insulator ◽  
Sensors And Actuators ◽  
In Situ Electron Microscopy ◽  
Ferroelectric Domains ◽  
Domain Boundaries ◽  
Domain Interactions ◽  
Memory Applications

In recent years, there has been a growing interest in the application of ferroelectric thin films for nonvolatile memory applications and as a gate insulator in DRAM structures. In addition, bulk ferroelectric materials are also widely used as components in electronic circuits and find numerous applications in sensors and actuators. To a large extent, the performance of ferroelectric materials are governed by the ferroelectric domains (with dimensions in the micron to sub-micron range) and the switching of domains in the presence of an applied field. Conventional TEM studies of ferroelectric domains structures, in conjunction with in-situ studies of the domain interactions can aid in explaining the behavior of ferroelectric materials, while providing some answers to the mechanisms and processes that influence the performance of ferroelectric materials. A few examples from bulk and thin film ferroelectric materials studied using the TEM are discussed below.Figure 1 shows micrographs of ferroelectric domains obtained from undoped and Fe-doped BaTiO3 single crystals. The domain boundaries have been identified as 90° domains with the boundaries parallel to <011>.

Response fitting in low-cost radiation sensors

2010 ◽  
Vol 1 (08) ◽  
pp. 920-925
Author(s):  
A. Gómez Moreno ◽  
P.J. Casanova Peláez ◽  
F.A. Díaz Garrido ◽  
J.M. Palomar Carnicero ◽  
R. López García ◽  
...  
Keyword(s):  
Low Cost ◽  
Fitting In ◽  
Radiation Sensors

High Temperature Smart Sensors and Actuators

1992 ◽  
Author(s):  
Oscar J. Almeida ◽  
Brian G. Dixon ◽  
Jill H. Hardin ◽  
John P. Sanford ◽  
Myles Walsh
Keyword(s):  
High Temperature ◽  
Smart Sensors ◽  
Sensors And Actuators

scholarly journals Bacterial Spore-Based Hygromorphs: A Novel Active Material with Potential for Architectural Applications

2021 ◽  
Vol 13 (7) ◽  
pp. 4030
Author(s):  
Emily Birch ◽  
Ben Bridgens ◽  
Meng Zhang ◽  
Martyn Dade-Robertson
Keyword(s):  
Bacillus Subtilis ◽  
Architectural Design ◽  
Energy Input ◽  
Shape Change ◽  
Active Material ◽  
Meaningful Work ◽  
Sensors And Actuators ◽  
Active Materials ◽  
Environmental Humidity ◽  
New Material

This paper introduces a new active material which responds to changes in environmental humidity. There has been growing interest in active materials which are able to respond to their environment, creating dynamic architectural systems without the need for energy input or complex systems of sensors and actuators. A subset of these materials are hygromorphs, which respond to changes in relative humidity (RH) and wetting through shape change. Here, we introduce a novel hygromorphic material in the context of architectural design, composed of multiple monolayers of microbial spores of Bacillus subtilis and latex sheets. Methods of fabrication and testing for this new material are described, showing that small actuators made from this material demonstrate rapid, reversible and repeatable deflection in response to changes in RH. It is demonstrated that the hygromorphic actuators are able to lift at least 150% of their own mass. Investigations are also extended to understanding this new biomaterial in terms of meaningful work.

scholarly journals Electronic Textiles

Encyclopedia ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 115-130
Author(s):  
Guido Ehrmann ◽  
Andrea Ehrmann
Keyword(s):  
Power Supply ◽  
Sensor Data ◽  
Electronic Textiles ◽  
Sensors And Actuators ◽  
External Communication ◽  
Data Processor ◽  
Temperature Strain

Electronic textiles belong to the broader range of smart (or “intelligent”) textiles. Their “smartness” is enabled by embedded or added electronics and allows the sensing of defined parameters of their environment as well as actuating according to these sensor data. For this purpose, different sensors (e.g., temperature, strain, light sensors) and actuators (e.g., LEDs or mechanical actuators) are embedded and connected with a power supply, a data processor, and internal/external communication.

Reliability of nonlinear stochastic controlled systems considering the dynamics of sensors and actuators

2021 ◽  
pp. 107754632110037
Author(s):  
Sun Jiaojiao ◽  
Xia Lei ◽  
Ying Zuguang ◽  
Huan Ronghua ◽  
Zhu Weiqiu
Keyword(s):  
Closed Loop ◽  
First Passage Time ◽  
Hamiltonian Function ◽  
Small Time ◽  
Kolmogorov Equation ◽  
Sensors And Actuators ◽  
First Passage ◽  
Controlled System ◽  
Main Structure ◽  
Controlled Systems

A closed-loop controlled system usually consists of the main structure, sensors, and actuators. The dynamics of sensors and actuators may influence the motion of the main structure. This article presents an analytical study on the first-passage reliability of a nonlinear stochastic controlled system under the consideration of the dynamics of sensors and actuators. The coupled dynamic equations of the controlled systems with sensors and actuators are first given, which are further integrated into a controlled, randomly excited, dissipated Hamiltonian system. By applying the stochastic averaging method for quasi-Hamiltonian systems, a one-dimensional averaged differential equation for the Hamiltonian function is obtained. The backward Kolmogorov equation associated with the averaged equation is then derived for the first-passage reliability analysis, from which the approximate reliability function and probability density of first-passage time are obtained. The accuracy of the proposed procedure is demonstrated by an example. A comparative analysis of the reliability of the system with/without sensors and actuators is carried out, which indicates that ignoring sensors and actuators will make underestimation of the reliability of the closed-loop system with small time. However, when time increases, there appears the opposite trend. Our findings provide a reference for control strategy design.

Sign in / Sign up

Export Citation Format

Share Document