scholarly journals Conformal coating by photoresist of sharp corners of anisotropically etched through-holes in silicon

Author(s):  
M. Heschel ◽  
S. Bouwstra
Author(s):  
Peter Marvin Müller ◽  
Niklas Kühl ◽  
Martin Siebenborn ◽  
Klaus Deckelnick ◽  
Michael Hinze ◽  
...  

AbstractWe introduce a novel method for the implementation of shape optimization for non-parameterized shapes in fluid dynamics applications, where we propose to use the shape derivative to determine deformation fields with the help of the $$p-$$ p - Laplacian for $$p > 2$$ p > 2 . This approach is closely related to the computation of steepest descent directions of the shape functional in the $$W^{1,\infty }-$$ W 1 , ∞ - topology and refers to the recent publication Deckelnick et al. (A novel $$W^{1,\infty}$$ W 1 , ∞ approach to shape optimisation with Lipschitz domains, 2021), where this idea is proposed. Our approach is demonstrated for shape optimization related to drag-minimal free floating bodies. The method is validated against existing approaches with respect to convergence of the optimization algorithm, the obtained shape, and regarding the quality of the computational grid after large deformations. Our numerical results strongly indicate that shape optimization related to the $$W^{1,\infty }$$ W 1 , ∞ -topology—though numerically more demanding—seems to be superior over the classical approaches invoking Hilbert space methods, concerning the convergence, the obtained shapes and the mesh quality after large deformations, in particular when the optimal shape features sharp corners.


Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 82
Author(s):  
Helmut Thissen ◽  
Richard A. Evans ◽  
Vincent Ball

In recent years major advances in surface chemistry and surface functionalization have been performed through the development, most often inspired by living organisms, of versatile methodologies. Among those, the contact of substrates with aminomalononitrile (AMN) containing solutions at pH = 8.5 allows a conformal coating to be deposited on the surface of all known classes of material. Since AMN is a molecule probably formed in the early atmosphere of our planet and since HCN-based compounds have been detected on many comets and Titan (Saturn’s largest moon) it is likely that such molecules will open a large avenue in surface functionalization mostly for bio-applications. This mini review describes the state of the art of AMN-based coatings from their deposition kinetics, composition, chemical reactivity, hypothetical structure to their first applications as biomaterials. Finally, the AMN-based versatile coatings are compared to other kinds of versatile coating based on catecholamines and polyphenols.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 338
Author(s):  
Hak Hyeon Lee ◽  
Dong Su Kim ◽  
Ji Hoon Choi ◽  
Young Been Kim ◽  
Sung Hyeon Jung ◽  
...  

An effective strategy for improving the charge transport efficiency of p-type Cu2O photocathodes is the use of counter n-type semiconductors with a proper band alignment, preferably using Al-doped ZnO (AZO). Atomic layer deposition (ALD)-prepared AZO films show an increase in the built-in potential at the Cu2O/AZO interface as well as an excellent conformal coating with a thin thickness on irregular Cu2O. Considering the thin thickness of the AZO overlayers, it is expected that the composition of the Al and the layer stacking sequence in the ALD process will significantly influence the charge transport behavior and the photoelectrochemical (PEC) performance. We designed various stacking orders of AZO overlayers where the stacking layers consisted of Al2O3 (or Al) and ZnO using the atomically controlled ALD process. Al doping in ZnO results in a wide bandgap and does not degrade the absorption efficiency of Cu2O. The best PEC performance was obtained for the sample with an AZO overlayer containing conductive Al layers in the bottom and top regions. The Cu2O/AZO/TiO2/Pt photoelectrode with this overlayer exhibits an open circuit potential of 0.63 V and maintains a high cathodic photocurrent value of approximately −3.2 mA cm−2 at 0 VRHE for over 100 min.


1990 ◽  
Vol 2 (1) ◽  
pp. 44-57 ◽  
Author(s):  
Steven W. Zucker ◽  
Lee Iverson ◽  
Robert A. Hummel

Consider two wire gratings, superimposed and moving across each other. Under certain conditions the two gratings will cohere into a single, compound pattern, which will appear to be moving in another direction. Such coherent motion patterns have been studied for sinusoidal component gratings, and give rise to percepts of rigid, planar motions. In this paper we show how to construct coherent motion displays that give rise to nonuniform, nonrigid, and nonplanar percepts. Most significantly, they also can define percepts with corners. Since these patterns are more consistent with the structure of natural scenes than rigid sinusoidal gratings, they stand as interesting stimuli for both computational and physiological studies. To illustrate, our display with sharp corners (tangent discontinuities or singularities) separating regions of coherent motion suggests that smoothing does not cross tangent discontinuities, a point that argues against existing (regularization) algorithms for computing motion. This leads us to consider how singularities can be confronted directly within optical flow computations, and we conclude with two hypotheses: (1) that singularities are represented within the motion system as multiple directions at the same retinotopic location; and (2) for component gratings to cohere, they must be at the same depth from the viewer. Both hypotheses have implications for the neural computation of coherent motion.


Sign in / Sign up

Export Citation Format

Share Document