Wafer-Scale Patterning of Protein Templates for Hydrogel Fabrication

Human-induced pluripotent stem cell-derived cardiomyocytes are a potentially unlimited cell source and promising patient-specific in vitro model of cardiac diseases. Yet, these cells are limited by immaturity and population heterogeneity. Current in vitro studies aiming at better understanding of the mechanical and chemical cues in the microenvironment that drive cellular maturation involve deformable materials and precise manipulation of the microenvironment with, for example, micropatterns. Such microenvironment manipulation most often involves microfabrication protocols which are time-consuming, require cleanroom facilities and photolithography expertise. Here, we present a method to increase the scale of the fabrication pipeline, thereby enabling large-batch generation of shelf-stable microenvironment protein templates on glass chips. This decreases fabrication time and allows for more flexibility in the subsequent steps, for example, in tuning the material properties and the selection of extracellular matrix or cell proteins. Further, the fabrication of deformable hydrogels has been optimized for compatibility with these templates, in addition to the templates being able to be used to acquire protein patterns directly on the glass chips. With our approach, we have successfully controlled the shapes of cardiomyocytes seeded on Matrigel-patterned hydrogels.

Transparent origami glass

The art of origami has emerged as an engineering tool with ever increasing potential, but the technique is typically limited to soft and deformable materials. Glass is indispensable in many applications, but its processing options are limited by its brittle nature and the requirement to achieve optical transparency. We report a strategy that allows making three dimensional transparent glass with origami techniques. Our process starts from a dynamic covalent polymer matrix with homogeneously dispersed silica nanoparticles. Particle cavitation and dynamic bond exchange offer two complementary plasticity mechanisms that allow the nanocomposite to be permanently folded into designable geometries. Further pyrolysis and sintering convert it into transparent three dimensional glass. Our method expands the scope of glass shaping and potentially opens up its utilities in unexplored territories.

Topological representation of cloth state for robot manipulation

Forty years ago the notion of configuration space (C-space) revolutionised robot motion planning for rigid and articulated objects. Despite great progress, handling deformable materials has remained elusive because of their infinite-dimensional shape-state space. Finding low-complexity representations has become a pressing research goal. This work tries to make a tiny step in this direction by proposing a state representation for textiles relying on the C-space of some distinctive points. A stratification of the configuration space for n points in the cloth is derived from that of the flag manifold, and topological techniques to determine adjacencies in manipulation-centred state graphs are developed. Their algorithmic implementation permits obtaining cloth state–space representations of different granularities and tailored to particular purposes. An example of their usage to distinguish between cloth states having different manipulation affordances is provided. Suggestions on how the proposed state graphs can serve as a common ground to link the perception, planning and manipulation of textiles are also made.

A New Methodology for Predicting Brittle Fracture of Plastically Deformable Materials: Application to a Cold Shell Nosing Process

The traditional theory of ductile fracture has limitations for predicting crack generation during a cold shell nosing process. Various damage criteria are employed to explain fracture and failure in the nose part of a cold shell. In this study, differences in microstructure among fractured materials and analysis of their surfaces indicated the occurrence of brittle fractures. The degree of “plastic deformation-induced embrittlement” (PDIE) of plastically deformable materials affects the likelihood of brittle fractures; PDIE can also decrease the strength in tension due to the Bauschinger effect. Two indicators of brittle fracture are presented, i.e., the critical value of PDIE and the allowable tensile strength (which in turn depends on the degree of PDIE or embrittlement-effective strain). When the maximum principal stress is greater than the latter and the PDIE is greater than the former, our method determines the likelihood of brittle fracture. This approach was applied to an actual cold shell nosing process, and the predictions were in good quantitative agreement with the experimental results.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. EXPERIMENTAL VERIFICATION OF THEORETICAL RESULTS AT DIFFERENT TAPER ANGLES OF THE MATRIX

The results of an experimental verification of the obtained theoretical formulas are presented, which make it possible to determine the most important parameters for extruding glasses with a counter-punch at different taper angles of the matrix. The characteristics of the tools used, the geometric parameters of extrusion experiments, the strength characteristics of deformable materials, and their lubrication are described in detail. Extraction studies of both non-hardening and hardening material have been performed. The methodology for performing theoretical calculations is shown in detail. The high accuracy of the obtained calculation formulas is confirmed.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. EXPERIMENTAL VERIFICATION OF THEORETICAL RESULTS WHEN EXTRUDING BRASS L63 AND STEEL 12X18H9T

The results of an experimental verification of the obtained theoretical formulas are presented, which make it possible to determine the most important parameters of advanced glasses with a control lunar layer of brass L63 and steel 12X18H9T. Detailed characteristics of the tools used, geometric parameters of extrusion experiments, strength characteristics of deformable materials, as well as their lubrication. Click on the methodology for performing theoretical calculations in detail. The high accuracy of the obtained results of the calculation formulas is confirmed.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. EXPERIMENTAL VERIFICATION OF THEORETICAL RESULTS FOR DIFFERENT CAVITY RADII AND BOTTOM THICKNESSES

The results of an experimental verification of the obtained theoretical formulas are presented, which make it possible to determine the most important parameters for extruding glasses with a counter-punch for different cavity radii and bottom thicknesses. The characteristics of the tools used, the geometric parameters of the extrusion experiments, the strength characteristics of deformable materials, and their lubrication are described in detail. Extrusion studies of both non-hardening and hardening material have been performed. The methodology for performing theoretical calculations is shown in detail. The high accuracy of the calculated calculation formulas is confirmed.

PUNCHING CUPS WITH BOTTOM FLANGE BY DIRECT EXTRUSION WITH COUNTER-PUNCH. INITIAL EXPERIMENTAL VERIFICATION OF THEORETICAL RESULTS

The goals of experimental verification of theoretical results are formulated. The results of an experimental verification of the obtained theoretical formulas are presented, which make it possible to determine the most important parameters for extruding glasses with a counter-punch. The characteristics of the tools used, the geometric parameters of the extrusion experiments, the strength characteristics of deformable materials, and their lubrication are described in detail. Studies of extrusion of non-hardening material simulating hot deformation are carried out. The high accuracy of the obtained calculation formulas is confirmed.

MECHANISM AND CHARACTERISTICS OF GEL FUEL IGNITION

Recently, prospective direction of the combustion theory development is the preparation of fuel compositions and study of the composite fuels ignition characteristics, for example, in the form of emulsions and suspensions. Such fuels and their combustion processes are characterized by higher environmental, energy, economic, and operational properties. Of great interest is the use of gel fuels prepared by thickening emulsions and suspensions to the state of elastically deformable materials for the aerospace industry and thermal power engineering. Gel fuels have advantages over widespread liquid fuels in environmental and fire safety aspects of storage processes, transportation, and combustion.