Search

We demonstrate the successful replication of biological surface structures, specifically the surface of the ventral snake skin, onto polymer foils using UV-assisted nanoimprint lithography (NIL). The foils were used as mold inlays for ceramic injection molding. Additionally, artificial structures mimicking the snake skin were designed by 3D lithography. The size of the features that can be replicated into the ceramics depends on the ceramic grain size after sintering. This study demonstrates that the transfer of complex biological and artificial structures onto the surfaces of non-flat ceramic parts is possible, including their anisotropic friction-reducing properties. [ABSTRACT FROM AUTHOR]

Electron beam grayscale lithography and selective thermal polymer reflow were combined to realize replication master having a bio-inspired surface topography. It consists of an array of asymmetric denticles with two-directional gradients on different length-scales. Each denticle has a sharp pin of 2 μm height on one and a smooth taper on the other side. In contrast to funnel-like structures having only vertical sidewalls, master with a sidewall angle smoothly changing between 15° and 70° were prepared. Discrete patterns, predefined by electron beam lithography, were transformed by reflow into well-defined, continuous, final device structures. Starting from stepped structures with only a few levels, this new approach of tapering allowed a very smooth transition from steep, sub-500 nm regions with aspect ratios up to four towards very broad and shallow regions within the same structure. This enabled the origination of master structures to be used for replication as low-frictional, durable, bio-inspired surfaces by ceramic powder injection molding. [ABSTRACT FROM AUTHOR]

While ethical considerations regarding the care of patients with erectile dysfunction have been previously described, there remains a paucity of literature regarding ethics as it pertains to penile prosthesis surgery. As the prevalence of erectile dysfunction increases, there is a need to further evaluate the ethical challenges penile prosthesis surgery presents to patients and clinicians. The purpose of our study was to investigate how practicing urological prosthetic surgeons approach ethically challenging scenarios that arise in penile prosthesis surgery and to describe which patient-related factors impact their approach. [Extracted from the article]