5,751 research outputs found
Recrystallized parylene as a mask for silicon chemical etching
This paper presents the first use of recrystallized
parylene as masking material for silicon chemical etch.
Recrystallized parylene was obtained by melting parylene C at
350°C for 2 hours. The masking ability of recrystallized parylene
was tested in HNA (hydrofluoric acid, nitric acid and acetic acid)
solution of various ratios, KOH (potassium hydroxide) solution
and TMAH (tetramethylammonium hydroxide) at different
temperatures and concentrations. It is found that interface
between parylene and the substrate can be attacked, which
results in undercuts. Otherwise, recrystallized parylene exhibited
good adhesion to silicon, complete protection of unexposed silicon
and silicon etching rates comparable to literature data
Q-enhanced fold-and-bond MEMS inductors
This work presents a novel coil fabrication technology
to enhance quality factor (Q factor) of microfabricated inductors
for implanted medical wireless sensing and data/power transfer
applications. Using parylene as a flexible thin-film device
substrate, a post-microfabrication substrate folding-and-bonding
method is developed to effectively increase the metal thickness of
the surface-micromachined inductors, resulting in their lower
self-resistance so their higher quality factor. One-fold-and-bond
coils are successfully demonstrated as an example to verify the
feasibility of the fabrication technology with measurement results
in good agreements with device simulation. Depending on target
specifications, multiple substrate folding-and-bonding can be
extensively implemented to facilitate further improved electrical
characteristics of the coils from single fabrication batch. Such Q-enhanced
inductors can be broadly utilized with great potentials
in flexible integrated wireless devices/systems for intraocular
prostheses and other biomedical implants
The Multi-shadow Analysis of LED Secondary Optics
AbstractDue to these advantages, small size, low heat radiation, long life time, and high luminous efficiency, the light-emitting diodes (LEDs) have been used widely to the varied lighting in recent years. However, the LEDs have the higher intensity of light in central region and the scattering in the surrounding during lighting, so it is necessary to modify the LED projection by the secondary optical lens. The extra secondary optical lens can enhance the light collection efficiency of LED, but it will readily induce the multi-shadow phenomenon during lighting, which has a significant impact on the human vision. In this study, the LED illumination module with/without secondary optical lens, total internal reflected (TIR) lens or reflection mirror cup, can be simulated by the Apilux(R) optical software. The result indicates that the approach can identify the level of multi-shadow images according to the deviations in light intensity, and will be new performance criteria of LEDs for users
The Active And Interactive Thinking Learning Research In Flip Education
In 2014 a total of 183 schools and 40 high schools participating in the experiment, the schools are in the Tablet PC as a learning tool, application-oriented learning and teaching strategies topics flipped learning, so that students in the teacher\u27s guide concept after active exploration program, in peer under the cooperative learning deepen CBC. After the rise of the majority of primary and secondary schools flipped classroom teacher began groping flip-teaching philosophy, the domestic schools have been put into digital teaching become common trend, there is a period of systematic research in schools to promote the use of the Internet and action vehicles, auxiliary in teaching of information technology equipment, emphasizes active learning, enhance learning interaction between teachers and learners understand and factors influencing teaching effectiveness, so with this initiative (active) and interactive (interactive) flip teaching experiment program
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