The Fraunhofer Society (German: Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e. V., lit. 'Fraunhofer Society for the Advancement of Applied Research'[note 1]) is a German research organization with 75 institutes spread throughout Germany, each focusing on different fields of applied science (as opposed to the Max Planck Society, which works primarily on basic science). With some 29,000 employees, mainly scientists and engineers, and with an annual research budget of about €2.8 billion, it is the biggest organization for applied research and development services in Europe.Some basic funding for the Fraunhofer Society is provided by the state (the German public, through the federal government together with the states or Länder, "owns" the Fraunhofer Society), but more than 70% of the funding is earned through contract work, either for government-sponsored projects or from industry.It is named after Joseph von Fraunhofer who, as a scientist, an engineer, and an entrepreneur, is said to have superbly exemplified the goals of the society.The organization has seven centers in the United States, under the name "Fraunhofer USA", and three in Asia. In October 2010, Fraunhofer announced that it would open its first research center in South America.Fraunhofer UK Research Ltd was established as a legally independent affiliate along with its Fraunhofer Centre for Applied Photonics, in Glasgow, Scotland, in March 2012.
Polyelectrolyte capsules (PEC) are hollow polymer particles fabricated by layer-by-layer (LbL) assembly of subsequently deposited polyelectrolytes of alternating charge. PECs, valued for their tunability and cargo encapsulation capabilities, are interesting for biomedical applications, underscoring the need for standardized fabrication and characterization techniques to optimize it for specific biomedical tasks. Here common protocols on how to synthesize and characterize such capsules are summarized. The fabrication of both, biodegradable and non-biodegradable capsules ranging in size from 800 nm to 5 μm is outlined. The entire preparation process—from the synthesis of sacrificial templates with diverse sizes and morphologies, to the controlled LbL deposition of polyelectrolyte shells and subsequent core dissolution is detailed. Here, calcium carbonate is selected as the sacrificial template of focus, owing to its high biocompatibility and loading capacity. Particular emphasis is placed on strategies for cargo loading, including co-precipitation and post-loading methods. Furthermore, the key characterization methods essential for confirming PEC formation—including size and zeta potential measurements (via dynamic light scattering), capsule concentration analysis (using optical or fluorescence microscopy), cargo encapsulation quantification (by UV-Vis spectroscopy or fluorescence analysis), and structural analysis (using transmission electron microscopy, TEM)—are highlighted and discussed. Finally, the review addresses current advantages and limitations in PEC fabrication, such as scalability and uniformity, and proposes future directions involving microfluidics, automation, and template design for the next generation of advanced biomedical applications.
Myocardial infarction in humans causes an irreversible scar, which permanently impairs cardiac mechanical properties and physiological functions. The zebrafish heart resolves scar tissue and regenerates injured myocardium. To study mechanical properties during regeneration, we developed a method combining atomic force microscope-based nanoindentation with confocal microscopy and generated a high-resolution elasticity map of the zebrafish heart. This revealed distinct regions of stiffness within the injury site, including a stiff area that is cell-poor and fibrin-rich, contrasting with the softer injury center and surrounding myocardium. Whole-transcriptome analyses uncovered several components of the coagulation and fibrinolysis cascades in the regenerating heart. Pharmacological inhibition of the fibrinolysis regulator Serpine1 demonstrated that reduced fibrin-mediated stiffness impacts the biomechanical Hippo pathway in adjacent endocardial cells. Our approach characterizes the mechanical properties of different regions in the regenerating heart and shows that the biomechanical environment and mechanotransductive signaling are crucial components for understanding regenerative mechanisms.
Abstract This article provides a general overview of bio-based resins, first examining biological sources for feedstocks of bio-based resin components, followed by a detailed description of five major resin classes (phenolic, furane, unsaturated polyester, epoxy, and benzoxazine resins) and their bio-based alternatives. It also describes the methods used to synthesize and modify the bio-based resins based on the biological feedstock, manufacturing processes, and properties of neat resins in comparison to fiber-reinforced composites. Then, the current work on novel bio-based vinyl ester, acrylic, and bismaleimide resins is highlighted. The article also reviews the work on the use of renewable resources to produce bio-resins with respect to composite applications, because only the development of bio-based resins leads to the production of sustainable green composites.
Abstract The potential of geothermal resources is currently limited by existing drilling technology. To address this issue, the DeepU project is investigating the use of laser to drill deep wells (>4 km) to create a U-shaped closed-loop geothermal heat exchanger. This technology includes a high-power laser source and optics, a drill string, a drill head, a flushing system making use of cryogenic supercritical nitrogen and some ancillary systems required for successful rock penetration. Supercritical nitrogen is transferred down the borehole, then after isenthalpic expansion of the gas, it vitrifies the rock and flushes the rock debris to the surface. Mathematical model of nitrogen flow during the laser drilling was developed. Pneumatic transport modelling provided information on the required supply of supercritical nitrogen to provide the necessary cooling power and pneumatic transport of cuttings to the surface. Vacuum insulation was selected for the supercritical nitrogen transfer pipe. A custom coupling system was designed to ensure tightness, robustness and ease of assembly. Potential failure modes of the proposed system were identified and mitigation steps were proposed. The study demonstrates the feasibility of delivering supercritical nitrogen to a borehole several kilometres deep.
We present a method for directly (sub-)micropatterning cellulose thin films using microcontact printing with a polymer-brush stamp that carries reactive imidazole groups. These groups temporarily bind carboxylic-acid inks, enabling clean ester-forming transfer to cellulose without smearing, allowing high-resolution micro- or nanometre-scale chemical patterning for functional paper fabrication in a simple and efficient fabrication process.
