Abstract: This research aims to design and build a wet etching system, which is suitable for anisotropic wet etching, in order to reduce etching time, to reduce hillocks on the etched surface (to reduce roughness), and to create a 45-degree wall angle (micro-mirror). This study would start by designing a wet etching system. There are four main components in this system: an ultrasonic cleaning, a condenser, a motor and a substrate holder. After that, an ultrasonic machine was modified by applying a condenser to maintain the consistency of the solution concentration during the etching process and installing a motor for improving the roughness. This effect on the etch rate and the roughness showed that the etch rate increased and the roughness was reduced.
Abstract: In this current contribution, authors are dedicated to
investigate influence of the crystal lamellae orientation on
electromechanical behaviors of relaxor ferroelectric Poly
(vinylidene fluoride –trifluoroethylene -chlorotrifluoroethylene)
(P(VDF-TrFE-CTFE)) films by control of polymer microstructure,
aiming to picture the full map of structure-property relationship. In
order to define their crystal orientation films, terpolymer films were
fabricated by solution-casting, stretching and hot-pressing process.
Differential scanning calorimetry, impedance analyzer, and tensile
strength techniques were employed to characterize crystallographic
parameters, dielectric permittivity, and elastic Young’s modulus
respectively. In addition, large electrical induced out-of-plane
electrostrictive strain was obtained by cantilever beam mode.
Consequently, as-casted pristine films exhibited surprisingly high
electrostrictive strain 0.1774% due to considerably small value of
elastic Young’s modulus although relatively low dielectric
permittivity. Such reasons contributed to large mechanical elastic
energy density. Instead, due to 2 folds increase of elastic Young’s
modulus and less than 50% augmentation of dielectric constant, fullycrystallized
film showed weak electrostrictive behavior and
mechanical energy density as well. And subjected to mechanical
stretching process, Film C exhibited stronger dielectric constant and
out-performed electrostrictive strain over Film B because edge-on
crystal lamellae orientation induced by uniaxially mechanical stretch.
Hot-press films were compared in term of cooling rate. Rather large
electrostrictive strain of 0.2788% for hot-pressed Film D in
quenching process was observed although its dielectric permittivity
equivalent to that of pristine as-casted Film A, showing highest
mechanical elastic energy density value of 359.5 J/m3. In hot-press
cooling process, dielectric permittivity of Film E saw values at 48.8
concomitant with ca.100% increase of Young’s modulus. Films with
intermediate mechanical energy density were obtained.
Abstract: The electrolyte stirring method of anodization etching
process for manufacturing porous silicon (PS) is reported in this work.
Two experimental setups of nature air stirring (PS-ASM) and
electrolyte stirring (PS-ESM) are employed to clarify the influence of
stirring mechanisms on electrochemical etching process. Compared to
traditional fabrication without any stirring apparatus (PS-TM), a large
plateau region of PS surface structure is obtained from samples with
both stirring methods by the 3D-profiler measurement. Moreover, the
light emission response is also improved by both proposed electrolyte
stirring methods due to the cycling force in electrolyte could
effectively enhance etch-carrier distribution while the electrochemical
etching process is made. According to the analysis of statistical
calculation of photoluminescence (PL) intensity, lower standard
deviations are obtained from PS-samples with studied stirring methods,
i.e. the uniformity of PL-intensity is effectively improved. The
calculated deviations of PL-intensity are 93.2, 74.5 and 64,
respectively, for PS-TM, PS-ASM and PS-ESM.
Abstract: In this paper, design, fabrication and coupled
multifield analysis of hollow out-of-plane silicon microneedle array
with piezoelectrically actuated microfluidic device for transdermal
drug delivery (TDD) applications is presented. The fabrication
process of silicon microneedle array is first done by series of
combined isotropic and anisotropic etching processes using
inductively coupled plasma (ICP) etching technology. Then coupled
multifield analysis of MEMS based piezoelectrically actuated device
with integrated 2×2 silicon microneedle array is presented. To predict
the stress distribution and model fluid flow in coupled field analysis,
finite element (FE) and computational fluid dynamic (CFD) analysis
using ANSYS rather than analytical systems has been performed.
Static analysis and transient CFD analysis were performed to predict
the fluid flow through the microneedle array. The inlet pressure from
10 kPa to 150 kPa was considered for static CFD analysis. In the
lumen region fluid flow rate 3.2946 μL/min is obtained at 150 V for
2×2 microneedle array. In the present study the authors have
performed simulation of structural, piezoelectric and CFD analysis
on three dimensional model of the piezoelectrically actuated
mcirofluidic device integrated with 2×2 microneedle array.
Abstract: The selective wet-etching of amorphous and
crystalline region of Sb20Se80 thin films was carried out using organic
based solution e.g. amines. We report the development of an in situ
real-time method to study the wet chemical etching process of thin
films. Characterization of the structure and surface of films studied
by X-ray diffraction, SEM and EBSD methods has been done and
potential application suggested.