The ability to achieve simultaneous intrinsic deformation with fast response in commercially available materials that can safely contact skin continues to be an unresolved challenge for artificial actuating materials. Rather than using a microporous structure, here we show an ambient-driven actuator that takes advantage of inherent nanoscale molecular channels within a commercial perfluorosulfonic acid ionomer (PFSA) film, fabricated by simple solution processing to realize a rapid response, self-adaptive, and exceptionally stable actuation. Selective patterning of PFSA films on an inert soft substrate (polyethylene terephthalate film) facilitates the formation of a range of different geometries, including a 2D (two-dimensional) roll or 3D (three-dimensional) helical structure in response to vapor stimuli. Chemical modification of the surface allowed the development of a kirigami-inspired single-layer actuator for personal humidity and heat management through macroscale geometric design features, to afford a bilayer stimuli-responsive actuator with multicolor switching capability.

Both primary and secondary nucleation rates are considered in a model developed for unseeded batch crystallization. A carefully designed strategy was employed to minimize the effects of the stochastic nature of induction time; nucleation was induced at designed supersaturations on known temperature plateaus. Crystallization kinetics of paracetamol from ethanolic solutions were extracted from measurements of in situ solute concentrations and combined with sieve (ex situ) data on the final product. Parameters in models for primary and secondary nucleation and for crystal growth rate were estimated by fitting a full population balance model to the measurements, and the evolution of the crystal size distribution was compared against in situ estimation from focused-beam reflectance measurements using the technique that we previously developed. The resulting models suggest that primary nucleation produces fewer surviving crystals than had been expected and that most of the product crystals from the process involving a temperature plateau result from secondary nucleation.

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Digital in-line holography (DIH) is broadly used to reconstruct 3D shapes of microscopic objects from their 2D holograms. One of the technical challenges in the reconstruction stage is eliminating the twin image originating from the phase-conjugate wavefront. The twin image removal is typically formulated as a non-linear inverse problem since the scattering process involved in generating the hologram is irreversible. Conventional phase recovery methods rely on multiple holographic imaging at different distances from the object plane along with iterative algorithms. Recently, end-to-end deep learning (DL) methods are utilized to reconstruct the object wavefront (as a surrogate for the 3D structure of the object) directly from the singleshot in-line digital hologram. However, massive data pairs are required to train the utilize DL model for an acceptable reconstruction precision. In contrast to typical image processing problems, well-curated datasets for in-line digital holography do not exist. The trained models are also highly influenced by the objects' morphological properties, hence can vary from one application to another. Therefore, data collection can be prohibitively laborious and time-consuming, as a critical drawback of using DL methods for DH. In this paper, we propose a novel DL method that takes advantages of the main characteristic of auto-encoders for blind single-shot hologram reconstruction solely based on the captured sample and without the need for a large dataset of samples with available ground truth to train the model. The simulation results demonstrate the superior performance of the proposed method compared to the state-of-the-art methods used for singleshot hologram reconstruction.

A high-resolution atomic force microscopy (AFM) study has shown that the molecular packing on the tetragonal lysozyme (110) face corresponds to only one of two possible packing arrangements, suggesting that growth layers on this face are of bimolecular height [Li et al. (1999). Acta Cryst. D55, 1023-1035]. Theoretical analyses of the packing also indicated that growth of this face should proceed by the addition of growth units of at least tetramer size, corresponding to the 43 helices in the crystal. In this study, an AFM linescan technique was used to measure the dimensions of individual growth units on protein crystal faces as they were being incorporated into the lattice. Images of individual growth events on the (110) face of tetragonal lysozyme crystals were observed, shown by jump discontinuities in the growth step in the linescan images. The growth-unit dimension in the scanned direction was obtained from these images. A large number of scans in two directions on the (110) face were performed and the distribution of lysozyme growth-unit sizes were obtained. A variety of unit sizes corresponding to 43 helices were shown to participate in the growth process, with the 43 tetramer being the minimum observed size. This technique represents a new application for AFM, allowing time-resolved studies of molecular processes to be carried out.