scholarly journals Thin Polymer Layers with Superparamagnetic Properties

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Kristin Trommer ◽  
Carina Petzold ◽  
Bernd Morgenstern
Keyword(s):  
Ambient Temperature ◽  
Large Scale ◽  
Magnetic Sensors ◽  
Superparamagnetic Nanoparticles ◽  
Sensors And Actuators ◽  
Flexible Polymer ◽  
Thin Polymer ◽  
Simple Processing ◽  
20 Nm ◽  
Superparamagnetic Properties

Superparamagnetic particles were widely used in medical applications as well as for magnetic sensors and actuators. Generally, the size of the particles is in the range of 10–20 nm. To use such particles in large-scale applications, a simple processing as well as the use of commercially available particles is required. Therefore superparamagnetic nanoparticles available on the market were incorporated in flexible polymer films and the magnetic properties of the films were investigated. At ambient temperature no significant hysteresis was observed, indicating the superparamagnetic properties. Films containing up to 25% nanoparticles were prepared. The films show a saturation magnetization of 13.8 Am2/kg and a coercivity of 7 Oe at ambient temperature.

Research on Thermally Induced Deformation of Reinforcing Plate Based on Finite Element Simulation

2012 ◽  
Vol 197 ◽  
pp. 139-143
Author(s):  
Hua Bai ◽  
Yi Du Zhang
Keyword(s):  
Finite Element ◽  
Ambient Temperature ◽  
Finite Element Simulation ◽  
Temperature Change ◽  
Large Scale ◽  
Machining Process ◽  
Reinforcement Structure ◽  
Thermally Induced ◽  
Finite Element Software ◽  
Element Simulation

The change of ambient temperature will cause deformation during the machining process of large-scale aerospace monolithic component. Based on finite element simulation, thermally induced deformation of reinforcing plate is studied in such aspects as reinforcement structure, clamping method and temperature change, and contact function in finite element software is used to simulate the unilateral constraint between workpiece and worktable. The results indicate that reinforcing plate will produce warping deformation due to the change of ambient temperature. Different reinforcement structures and clamping methods have important influence on the deformation positions and degrees, and the deformation is proportional to the temperature change.

scholarly journals A method for large scale implantation of 3D microdevice ensembles into brain and soft tissue

2020 ◽  
Author(s):  
Stefan A. Sigurdsson ◽  
Zeyang Yu ◽  
Joonhee Lee ◽  
Arto Nurmikko
Keyword(s):  
Polyethylene Glycol ◽  
High Throughput ◽  
Large Scale ◽  
Soft Tissues ◽  
Tissue Injury ◽  
Physiological Activity ◽  
Medical Diagnostics ◽  
Sensors And Actuators ◽  
Small Device ◽  
Minimal Damage

AbstractWireless networks of implantable electronic sensors and actuators on the microscale (sub-mm) are being explored for monitoring and modulation of physiological activity for medical diagnostics and therapeutic purposes. Beyond the requirement of integrating multiple electronic or chemical functions within small device volumes, a key challenge is the development of high-throughput methods for implantation of large numbers of microdevices into soft tissues with minimal damage. To that end, we have developed a method for high-throughput implantation of ∼100-200 μm size devices which are here simulated by proxy microparticle ensembles. While generally applicable to subdermal tissue, our main focus and experimental testbed is the implantation of microparticles into the brain. The method deploys a scalable delivery tool composed of a 2-dimensional array of polyethylene glycol tipped microneedles which confine the microparticle payloads. Upon dissolution of the bioresorbable polyethylene glycol, the supporting array structure is retrieved and the microparticles remain embedded in the tissue, distributed spatially and geometrically according to the design of the microfabricated delivery tool. We first evaluated the method in an agarose testbed in terms of spatial precision and throughput for up to 1000 passive spherical and planar microparticles acting as proxy devices. We then performed the same evaluations of particles implanted into the rat cortex under acute conditions and assessed the tissue injury produced by our method of implantation under chronic conditions.

scholarly journals Extra Surfactant-Assisted Self-Assembly of Highly Ordered Monolayers of BaTiO3 Nanocubes at the Air—Water Interface

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 739 ◽  
Author(s):  
Hiroki Itasaka ◽  
Ken-Ichi Mimura ◽  
Kazumi Kato
Keyword(s):  
Self Assembly ◽  
Large Scale ◽  
Three Dimensional ◽  
Water Interface ◽  
Compression Pressure ◽  
Air Water Interface ◽  
Out Of Plane ◽  
Key Factor ◽  
Evaporation Induced Self Assembly ◽  
20 Nm

Assembly of nanocrystals into ordered two- or three-dimensional arrays is an essential technology to achieve their application in novel functional devices. Among a variety of assembly techniques, evaporation-induced self-assembly (EISA) is one of the prospective approaches because of its simplicity. Although EISA has shown its potential to form highly ordered nanocrystal arrays, the formation of uniform nanocrystal arrays over large areas remains a challenging subject. Here, we introduce a new EISA method and demonstrate the formation of large-scale highly ordered monolayers of barium titanate (BaTiO3, BT) nanocubes at the air-water interface. In our method, the addition of an extra surfactant to a water surface assists the EISA of BT nanocubes with a size of 15–20 nm into a highly ordered arrangement. We reveal that the compression pressure exerted by the extra surfactant on BT nanocubes during the solvent evaporation is a key factor in the self-assembly in our method. The BT nanocube monolayers transferred to substrates have sizes up to the millimeter scale and a high out-of-plane crystal orientation, containing almost no microcracks and voids.

Optimal sensors and actuators placement for large-scale switched systems

2018 ◽  
Vol 7 (1) ◽  
pp. 147-156
Author(s):  
Masoud Seyed Sakha ◽  
Hamid Reza Shaker ◽  
Maryamsadat Tahavori
Keyword(s):  
Switched Systems ◽  
Large Scale ◽  
Sensors And Actuators

Large-scale fabrication of all-inkjet-printed resistors and WORM memories on flexible polymer films with high yield and stability

2021 ◽  
Vol 6 (1) ◽  
pp. 015003
Author(s):  
Eloi Ramon ◽  
Enrico Sowade ◽  
Carme Martínez-Domingo ◽  
Kalyan Yoti Mitra ◽  
Ana Alcalde ◽  
...  
Keyword(s):  
Polymer Films ◽  
Large Scale ◽  
High Yield ◽  
Flexible Polymer

Neural Networks Model for Optimization an Study on Isomorphism Discernment

2010 ◽  
Vol 156-157 ◽  
pp. 492-495
Author(s):  
Miao Zhang ◽  
Ning Bo Liao ◽  
Chen Zhou
Keyword(s):  
Neural Networks ◽  
Large Scale ◽  
Optimization Problems ◽  
Isomorphism Problem ◽  
Processing Elements ◽  
Feedback Network ◽  
Simple Processing ◽  
Np Complete ◽  
Is Design ◽  
Complete Optimization

An artificial neural network is composed of large number of simple processing elements by direct links named connections, the benefits of neural networks extend beyond the high computation rates by massive parallelism. Optimization problems could be transferred into a feedback network, the network interconnects the neurons with a feedback path. Graphs isomorphism discernment is one of the most important and difficult issues in graphs theory based structures design. To solve the problem, a Hopfield neural networks (HNN) model is presented in this paper. The solution of HNN is design as a permutation matrix of two graphs, and some operators are improved to prevent premature convergence. It is concluded that the algorithm presented here is efficient for large-scale graphs isomorphism problem and other NP-complete optimization issues.

Fabrication of Core-shell Type FeCo-Au (Ag) High Moment Magnetic Nanoparticles

2005 ◽  
Vol 877 ◽  
Author(s):  
Jianmin Bai ◽  
Yunhao Xu ◽  
Jian-Ping Wang
Keyword(s):  
Deposition Process ◽  
Superparamagnetic Nanoparticles ◽  
Core Shell ◽  
Physical Vacuum ◽  
Shell Type ◽  
On Line ◽  
High Magnetic Moment ◽  
20 Nm ◽  
Controllable Particle Size ◽  
Feco Nanoparticles

AbstractWe developed a physical vacuum deposition technique combining an on-line sputtering/evaporation process with an integrated nanocluster deposition process to prepare core-shell type nanoparticles. High magnetic moment (Fe60Co40)coreAushell and (Fe60Co40)coreAgshell superparamagnetic nanoparticles with controllable particle size of 10 – 20 nm and Au/Ag shell thickness of 1 – 3 nm were prepared successfully by using method. Au shell is not only functional for the potential biocompatibility but also the key to prevent oxidation of FeCo nanoparticles. Saturation magnetization of (Fe60Co40)coreAushell nanoparticles was found three times higher than that of iron oxide nanoparticles. This novel technique enables us to control independently the dimensions of core and shell and select individually materials for core and shell for other core-shell type nanoparticles.

scholarly journals Large-scale fabrication of highly ordered sub-20 nm noble metal nanoparticles on silica substrates without metallic adhesion layers

2018 ◽  
Vol 4 (1) ◽  
Author(s):  
Hai Le-The ◽  
Erwin Berenschot ◽  
Roald M. Tiggelaar ◽  
Niels R. Tas ◽  
Albert van den Berg ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Noble Metal ◽  
Large Scale ◽  
Noble Metal Nanoparticles ◽  
20 Nm ◽  
Silica Substrates

scholarly journals Design of a Tri-Axial Surface Micromachined MEMS Vibrating Gyroscope

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2822
Author(s):  
Rocco Crescenzi ◽  
Giuseppe Vincenzo Castellito ◽  
Simone Quaranta ◽  
Marco Balucani
Keyword(s):  
Integrated Circuit ◽  
Large Scale ◽  
Manufacturing Industry ◽  
Low Cost ◽  
High Volume ◽  
Electronic System ◽  
Sensors And Actuators ◽  
Micro Electro Mechanical Systems ◽  
Final Assembly ◽  
Comb Drives

Gyroscopes are one of the next killer applications for the MEMS (Micro-Electro-Mechanical-Systems) sensors industry. Many mature applications have already been developed and produced in limited volumes for the automotive, consumer, industrial, medical, and military markets. Plenty of high-volume applications, over 100 million per year, have been calling for low-cost gyroscopes. Bulk silicon is a promising candidate for low-cost gyroscopes due to its large scale availability and maturity of its manufacturing industry. Nevertheless, it is not suitable for a real monolithic IC integration and requires a dedicated packaging. New designs are supposed to eliminate the need for magnets and metal case package, and allow for a real monolithic MEMS-IC (Integrated Circuit) electronic system. In addition, a drastic cost reduction could be achieved by utilizing off-the-shelf plastic packaging with lead frames for the final assembly. The present paper puts forward the design of a novel tri-axial gyroscope based on rotating comb-drives acting as both capacitive sensors and actuators. The comb-drives are comprised of a single monolithic moving component (rotor) and fixed parts (stators). The former is made out of different concentrated masses connected by curved silicon beams in order to decouple the motion signals. The sensor was devised to be fabricated through the PolyMUMPs® process and it is intended for working in air in order to semplify the MEMS-IC monolithic integration.

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