Certain bat species (e.g. horseshoe bats, family Rhinolophidae) are known for conspicuous deformations of the emission baffles (noseleaves) and reception baffles (ears). Previously reported numerical studies and experiments with biomimetic reproductions of these baffles have shown that such deformations can result in time-variant emitter/receiver characteristics. However, it has not been investigated whether these time-variant characteristics could also manifest themselves in likewise time-variant properties in echoes from targets of varying complexity. To investigate this question, a biomimetic sonar head complete with deformable emission and reception baffles has been used to ensonify targets with different simple geometries (sphere, cylinder, and cube) as well as random, more natural target geometries (artificial plants) from distances of about 1 meter. Time-variant echo signatures were found in all these cases, i.e. irrespective of target complexity and whether the time-variance was injected into the emission, the reception, or into both. This demonstrates that although the time-variant emission/reception characteristics had been previously measured only under careful conditions, they are capable of impacting real-world echoes. Even targets with distributed clouds of scattering facets did not obscure the effects of the changing conformation states. Hence these changes in ear position created by baffle deformations could serve the animals or man-made sonar systems that mimic them to encode additional echo information through time-variant echo signatures.

Embryonic morphogenesis is a biological process which depicts shape forming of tissues and organs during development. Unveiling the roles of mechanical forces generated, transmitted, and regulated in cells and tissues through these processes is key to understanding the biophysical mechanisms governing morphogenesis. To this end, it is imperative to measure, simulate, and predict the regulation and control of these mechanical forces during morphogenesis. This article aims to provide a comprehensive review of the recent advances on mechanical properties of cells and tissues, generation of mechanical forces in cells and tissues, the transmission processes of these generated forces during cells and tissues, the tools and methods used to measure and predict these mechanical forces in vivo, in vitro, or in silico, and to better understand the corresponding regulation and control of generated forces. Understanding the biomechanics and mechanobiology of morphogenesis will not only shed light on the fundamental physical mechanisms underlying these concerted biological processes during normal development, but also uncover new information that will benefit biomedical research in preventing and treating congenital defects or tissue engineering and regeneration.

Hydrogels provide a promising method for the targeted delivery of protein drugs. Loading the protein drug into the hydrogel free volume can be challenging due to limited quantities of the drug (e.g., growth factor) and complex physicochemical properties of the hydrogel. Here, we investigated both passive and active loading of the heteropolysaccharide hydrogel pectin. Passive loading of glass phase pectin films was evaluated by contact angles and fractional thickness of the pectin films. Four pectin sources demonstrated mean contact angles of 88° with water and 122° with pleural fluid (p < 0.05). Slow kinetics and evaporative losses precluded passive loading. In contrast, active loading of the translucent pectin films was evaluated with the colorimetric tracer methylene blue. Active loading parameters were systematically varied and recorded at 500 points/s. The distribution of the tracer was evaluated by image morphometry. Active loading of the tracer into the pectin films required the optimization of probe velocity, compression force, and contact time. We conclude that active loading using pectin-specific conditions is required for the efficient embedding of low viscosity liquids into pectin hydrogels.