3D buckligami: combinatorial mechanical metamaterials

We present a class of elastic structures which exhibit collective buckling in 3D, and create these by a 3D printing/moulding technique. Our structures consist of cubic lattice of anisotropic unit cells, and we show that their mechanical properties are programmable via the orientations of all unit cells. Collectively buckling, but nonperiodic, structures can be found by solving a combinatorial problem related to spin ice. Such nonperiodic structures present a novel pathway to maximally auxetic, isotropic metamaterials

Tunable buckling of metabeams

We probe the buckling of elastic metabeams by means of experiments and simulations. We show that sufficiently wide elastic plain beams exhibit snap through buckling, an unstable form of buckling where the stiffness is negative. We demonstrate that wider beams experience stronger nonlinear deformations and geometric stiffening. Therefore, the distribution of stresses across the beam is distorted and the postbuckling behavior altered. In a second part, we tailor a strain-softening nonlinearity in the material by designing an ordered microstructure close to a pattern transformation, in such a way that we can rationally design the postbuckling behavior of arbitrarily thin beams

Programmable mechanical metamaterials: BiHolar networks

We probe the mechanics of BiHolar metamaterials, 2D elastic media with a square lattice of circular holes of two different sizes. Biaxial loading of these BiHolar structures leads to a wealth of mechanical responses, including mechanically switchable hysteresis and memory effects. We show that we can program the mechanical response with the loading force and the hole size ratios

Shot-noise limited throughput of soft X-ray ptychography for nanometrology applications

Due to its potential for high resolution and three-dimensional imaging, soft X-ray ptychography has received interest for nanometrology applications. We have analyzed the measurement time per unit area when using soft X-ray ptychography for various nanometrology applications including mask inspection and wafer inspection, and are thus able to predict (order of magnitude) throughput figures. Here we show that for a typical measurement system, using a typical sampling strategy, and when aiming for 10-15 nm resolution, it is expected that a wafer-based topology (2.5D) measurement takes approximately 4 minutes per μm2, and a full three-dimensional measurement takes roughly 6 hours per μm2. Due to their much higher reflectivity EUV masks can be measured considerably faster; a measurement speed of 0.1 seconds per μm2 is expected. However, such speeds do not allow for full wafer or mask inspection at industrially relevant throughput

Narrative medicine pinpoints loss of autonomy and stigma in Parkinson’s disease

Abstract Parkinson’s disease characteristics can create a self-perceived sense of stigmatization and disapproval by others, thereby affecting self-perceived autonomy. This study investigated the metaphors related to the loss of autonomy and stigma in stories and drawings of Parkinson’s disease. We compare a contemporary first-person illness narrative and -drawing from a person with Parkinson’s disease, with two novels (Jonathan Franzen’s The Corrections and Claudia Piñeiro’s Elena Knows), a graphic novel (Peter Dunlap-Shohl’s My Degeneration: A Journey Through Parkinson’s), a non-fiction book (Oliver Sacks’ Awakenings) and a first-person illness narrative (John Palfreman’s The Bright Side of Parkinson’s). Metaphors in the patient narrative, novels, and non-fiction work were reviewed and a list of themes or categorizations common to 2 of the metaphors was generated. Parkinson’s disease metaphors indicate a ‘Parkinson’s prism’ thereby depicting extreme experiences (24.4%) like a ‘fall by mischance’, a ‘tantrum of selfish misery’ or a ‘bottomless darkness and unreality’ (Table 1). Both novels signify a sense of ‘betrayal and disconnection’ in the Parkinson’s disease experience while non-fiction of Parkinsonism depicts a space in which one feels ‘caged and deprived’. This makes the Parkinson’s disease narrative a chaos story that could influence the decision to initiate treatment and treatment adherence. We conclude that narrative medicine can help to focus the medical consultations with affected individuals on issues that matter most to them, thereby improving self-perceived autonomy and stigma. As such, it is a critical component of the much-needed move towards personalized medicine in Parkinson’s disease, achieved through the reciprocity of thinking with stories

Shot-noise limited throughput of soft X-ray ptychography for nanometrology applications

\u3cp\u3eDue to its potential for high resolution and three-dimensional imaging, soft X-ray ptychography has received interest for nanometrology applications. We have analyzed the measurement time per unit area when using soft X-ray ptychography for various nanometrology applications including mask inspection and wafer inspection, and are thus able to predict (order of magnitude) throughput figures. Here we show that for a typical measurement system, using a typical sampling strategy, and when aiming for 10-15 nm resolution, it is expected that a wafer-based topology (2.5D) measurement takes approximately 4 minutes per μm\u3csup\u3e2\u3c/sup\u3e, and a full three-dimensional measurement takes roughly 6 hours per μm\u3csup\u3e2\u3c/sup\u3e. Due to their much higher reflectivity EUV masks can be measured considerably faster; a measurement speed of 0.1 seconds per μm\u3csup\u3e2\u3c/sup\u3e is expected. However, such speeds do not allow for full wafer or mask inspection at industrially relevant throughput.\u3c/p\u3