Fabrication and Characterization of MEMS-Based Structures from a Bio-Inspired, Chemo-Responsive Polymer Nanocomposite

2011 ◽  
Vol 1299 ◽  
Author(s):  
Allison E. Hess ◽  
Christian A.. Zorman
Keyword(s):  
Electrochemical Impedance ◽  
Polymer Nanocomposite ◽  
Time Dependent ◽  
Stimuli Responsive ◽  
Responsive Polymer ◽  
Fabrication And Characterization ◽  
Phosphate Buffered Saline ◽  
Biomedical Microsystems ◽  
Exposed Surface Area

ABSTRACTThis paper reports the development of micromachining processes, as well as electrical and mechanical evaluation of a stimuli-responsive, mechanically-dynamic polymer nanocomposite for biomedical microsystems. The nanocomposite, which consists of a cellulose nanofiber network embedded in a poly(vinyl acetate) matrix, was shown to display a switchable stiffness comparable to bulk samples, with a Young’s modulus of 3570 MPa in the dry state, which reduced to ~25 MPa in the wet state, with a stiff-to-flexible transition-time dependent on exposed surface area. Upon immersion in phosphate buffered saline, the ac resistance through the PVAc-TW thickness was found to reduce from 8.04 MΩ to ~17 kΩ. Electrochemical impedance of an Au electrode on PVAc-TW was found to be ~178 kΩ at 1 kHz, and this was found to be stable as the probe shank was flexed to compress the metal, but increased with increasing flex angle when the metal was flexed into a tensile state.

scholarly journals Fabrication and Characterization of Ceramic Coating on Al7075 Alloy by Plasma Electrolytic Oxidation in Molten Salt

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 993
Author(s):  
Alexander Sobolev ◽  
Tamar Peretz ◽  
Konstantin Borodianskiy
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Electrochemical Impedance ◽  
Current Frequency ◽  
Electrolytic Oxidation ◽  
Fabrication And Characterization ◽  
Plasma Electrolytic

The fabrication of a ceramic coating on the metallic substrate is usually applied to achieve the improved performance of the material. Plasma electrolytic oxidation (PEO) is one of the most promising methods to reach this performance, mostly wear and corrosion resistance. Traditional PEO is carried out in an aqueous electrolyte. However, the current work showed the fabrication and characterization of a ceramic coating using PEO in molten salt which was used to avoid disadvantages in system heating-up and the formation of undesired elements in the coating. Aluminum 7075 alloy was subjected to the surface treatment using PEO in molten nitrate salt. Various current frequencies were applied in the process. Coating investigations revealed its surface porous structure and the presence of two oxide layers, α-Al2O3 and γ-Al2O3. Microhardness measurements and chemical and phase examinations confirmed these results. Potentiodynamic polarization tests and electrochemical impedance spectroscopy revealed the greater corrosion resistance for the coated alloy. Moreover, the corrosion resistance was increased with the current frequency of the PEO process.

scholarly journals Fabrication and Characterization of Magnetoresponsive Electrospun Nanocomposite Membranes Based on Methacrylic Random Copolymers and Magnetite Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Ioanna Savva ◽  
George Krekos ◽  
Alina Taculescu ◽  
Oana Marinica ◽  
Ladislau Vekas ◽  
...  
Keyword(s):  
Random Copolymers ◽  
Magnetic Characteristics ◽  
Stimuli Responsive ◽  
Nanocomposite Membranes ◽  
Electrospinning Technique ◽  
Responsive Materials ◽  
Fibrous Matrix ◽  
Fabrication And Characterization ◽  
Fibrous Membranes

Magnetoresponsive polymer-based fibrous nanocomposites belonging to the broad category of stimuli-responsive materials, is a relatively new class of “soft” composite materials, consisting of magnetic nanoparticles embedded within a polymeric fibrous matrix. The presence of an externally applied magnetic field influences the properties of these materials rendering them useful in numerous technological and biomedical applications including sensing, magnetic separation, catalysis and magnetic drug delivery. This study deals with the fabrication and characterization of magnetoresponsive nanocomposite fibrous membranes consisting of methacrylic random copolymers based on methyl methacrylate (MMA) and 2-(acetoacetoxy)ethyl methacrylate (AEMA) (MMA-co-AEMA) and oleic acid-coated magnetite (OA·Fe3O4) nanoparticles. The AEMA moieties containingβ-ketoester side-chain functionalities were introduced for the first time in this type of materials, because of their inherent ability to bind effectively onto inorganic surfaces providing an improved stabilization. For membrane fabrication the electrospinning technique was employed and a series of nanocomposite membranes was prepared in which the polymer content was kept constant and only the inorganic (OA·Fe3O4) content varied. Further to the characterization of these materials in regards to their morphology, composition and thermal properties, assessment of their magnetic characteristics disclosed tunable superparamagnetic behaviour at ambient temperature.

Developing Carbon Nanocomposite Smart Materials

2007 ◽  
Vol 119 ◽  
pp. 207-210 ◽  
Author(s):  
In Pil Kang ◽  
Joo Yung Jung ◽  
Gyeong Rak Choi ◽  
Hyung Ki Park ◽  
Jong Won Lee ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrochemical Properties ◽  
Smart Materials ◽  
Electrochemical Impedance ◽  
Smart Material ◽  
Nanocomposite Material ◽  
Fabrication And Characterization ◽  
Carbon Nanocomposite

To address the need for new smart materials, this paper explores the use of carbon nanotubes to develop a nanocomposite smart material having electrochemical impedance properties for sensing and actuation. Fabrication and characterization of the carbon nanocomposite material are discussed in the paper. The issues related to hurdles in the practical manufacturing of commodity level macro size nanocomposite smart materials with prescribed electrical and electrochemical properties are also discussed.

Fabrication and characterization of high strength Nylon-6/Si3N4 polymer nanocomposite fibers

2009 ◽  
Vol 500 (1-2) ◽  
pp. 92-97 ◽  
Author(s):  
Vijaya K. Rangari ◽  
Mohammad Y. Shaik ◽  
Hassan Mahfuz ◽  
Shaik Jeelani
Keyword(s):  
High Strength ◽  
Polymer Nanocomposite ◽  
Nylon 6 ◽  
Nanocomposite Fibers ◽  
Fabrication And Characterization

Fabrication and characterization of ultrathin dextran layers: Time dependent nanostructure in aqueous environments revealed by OWLS

2016 ◽  
Vol 146 ◽  
pp. 861-870 ◽  
Author(s):  
Andras Saftics ◽  
Sándor Kurunczi ◽  
Zsolt Szekrényes ◽  
Katalin Kamarás ◽  
Nguyen Quoc Khánh ◽  
...  
Keyword(s):  
Time Dependent ◽  
Aqueous Environments ◽  
Fabrication And Characterization
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