Nanoparticles are used in various fields, such as material manufacturing, catalysis and medicine, due to their unique physical and chemical properties. Accurate characterization of nanoparticles is essential for manufacturing purposes as well as for assessing their impact on the environment and human health. To achieve this, single particle inductively coupled plasma mass spectrometry (sp-ICP-MS) has become an essential analytical technique for nanoparticle analysis. It can also be used with laser ablation as a sampling method to overcome challenges related to introducing nanoparticles in liquid suspension. Similar to conventional sp-ICP-MS, laser ablation sp-ICP-MS requires standards for signal calibration, which is challenging as the availability of standard reference materials is limited for all different kinds of nanoparticles. In this work, nanoparticles embedded in polymer thin films are analyzed using laser ablation sp-ICP-MS, whereby the laser is used to sample and transport the intact particles to the plasma. For creating a calibration for mass and size investigations, defined amounts of the element of interest were introduced into the ICP-MS by quantitatively ablating polymer thin film spiked with a defined amount of liquid element standard with different laser spot sizes. The method was developed and optimized using gold nanoparticles with certified sizes that were analyzed using a quadrupole-ICP-MS in single-element mode. The nanoparticles were sized using the proposed calibration approach with a deviation of <= 2.5% from the certified diameter value. Using the calibration approach, a limit of detection for gold of 3 x 10-7 ng was calculated, which translates to a particle size of approximately 15.5 nm, comparable to values in the literature for liquid-suspension-based approaches. Multi-element nanoparticles in the form of gadolinium-doped cerium oxide (GDC) nanoparticles with two elements of interest were analyzed using an ICP-TOFMS utilizing the thin-film-based calibration approach. Comparative measurements of the material confirmed the investigated sizes and composition of the particles. This developed alternative approach circumvents the need for certified particulate standard materials by using in-house-produced spiked polymer thin films as storage-stable calibration standards. Moreover, changing the laser spot size makes it straightforward to alter the number of particles introduced into the ICP-MS.

The performance and flexibility of the latest robot technologies make it possible to bring more and more robots to everyday life. However, this also creates a number of challenges: safety, legal regulations, reliability, reusability, and also business models must be considered under special, difficult conditions in everyday life. Furthermore, the acceptance and interaction between humans and robots are of central importance for the success of service and assistance applications. This collection summarises 15 studies from the BMBF-funded program "Robots for Assistance: Interaction in the Field." The full studies are written in German and provide valuable insights into the challenges, potentials, and solutions for successful interaction in everyday environments. The collection is accompanied by this preface article, which, in addition to the interaction focus of the studies, addresses other important aspects for successful service and assistance robots in everyday life. Finally, the Human-Robot-Interaction (HRI) studies are summarised in English to enable the comparison and discussion of their challenges and approaches.

Der Einsatz von aktuellen Robotertechnologien im Alltag wird zunehmend möglich. Doch es ergeben sich Herausforderungen: Sicherheit, rechtliche Rahmenbedingungen, Zuverlässigkeit und Geschäftsmodelle müssen unter speziellen Bedingungen betrachtet werden. Auch Akzeptanz und Interaktion zwischen Mensch und Roboter sind zentral für den Erfolg. Dieser Sammelband fasst 15 Studien aus der BMBF Förderlinie “Roboter für Assistenzfunktionen: Interaktion in der Praxis” zusammen.

Laser ablation in combination with an inductively coupled plasma time-of-flight mass spectrometer (LA-ICP-TOFMS) is an upcoming method for rapid quantitative element mapping of various samples. While widespread in geological applications, quantification of elements in biotissues remains challenging. In this study, a proof-of-concept sample preparation method is presented in which plant-tissues are fossilized in order to solidify the complex biotissue matrix into a mineral-like matrix. This process enables quantification of elements by using silicone as an internal standard for normalization while also providing consistent ablation processes similar to minerals to reduce image blurring. Furthermore, it allows us to generate a quantitative image of the element composition at high spatial resolution. The feasibility of the approach is demonstrated on leaves of sunflowers (Helianthus annuus), soy beans (Glycine max), and corn (Zea mays) as representatives for common crops, which were grown on both nonspiked and cadmium-spiked agricultural soil. The quantitative results achieved during imaging were validated with digestion of whole leaves followed by ICP-OES analysis. LA-ICP-TOFMS element mapping of conventionally dried samples can provide misleading trends due to the irregular ablation behavior of biotissue because high signals caused by high ablation rates are falsely interpreted as enrichment of elements. Fossilization provides the opportunity to correct such phenomena by standardization with Si as an internal standard. The method demonstrated here allows for quantitative image acquisition without time-consuming sample preparation steps by using comparatively safe chemicals. The diversity of tested samples suggests that this sample preparation method is well-suited to achieve reproducible and quantitative element maps of various plant samples.

Hydrocarbon-based materials are of interest as next-generation proton exchange membranes (PEMs) for polymer electrolyte fuel cells (PEFCs). The biggest drawback of aromatic hydrocarbon PEMs is the presence of aromatic groups contained within the polymer, which make these materials susceptible to radical induced degradation reactions. In the fuel cell community antioxidant action is usually equated with scavenging of potent radicals, i.e. HO•, by various additives. In this work, however, we report on the repair of damaged membranes. This is tested by performing in situ accelerated stress tests at open circuit voltage with high H2 and O2 partial pressures. Membranes with aromatic sulfonate groups are synthesized as these are common constituents in hydrocarbon-based membranes. Two different approaches to incorporate the repair agent, cerium(III), are explored: 1) ionic bonding of Ce(III) to sulfonate groups and 2) covalent attachment through stable complexes of crown ether and Ce(III). We report that, during fuel cell operation, polymer degradation can be significantly reduced by Ce(III) when immobilized in the membrane. Ionic attachment did not yield in the desired repair effect as a result of cerium loss from the membrane.

Graphene quantum dots are promising candidates for qubits due to weak spin-orbit and hyperfine interactions. The hyperfine interaction, controllable via isotopic purification, could be the key to further improving the coherence. Here, we use isotopically enriched graphite crystals of both 12C and 13C grown by a high-pressure high-temperature method to exfoliate graphene layers. We fabricated Hall bar devices and performed quantum transport measurements, revealing mobilities exceeding 105 cm2/V s and a long mean free path of microns, which are as high as natural graphene. Shubnikov-de Haas oscillations, quantum Hall effect up to the filling factor of one, and Brown-Zak oscillations due to the alignment of hBN and graphene are observed thanks to the high mobility. These results constitute a material platform for physics and engineering of isotopically enriched graphene qubits.

The use of hydrocarbon-based proton conducting membranes in fuel cells is currently hampered by the insufficient durability of the material in the device. Membrane aging is triggered by the presence of reactive intermediates, such as HO⋅, which attack the polymer and eventually lead to chain breakdown and membrane failure. An adequate antioxidant strategy tailored towards hydrocarbon-based ionomers is therefore imperative to improve membrane lifetime. In this work, we perform studies on reaction kinetics using pulse radiolysis and γ-radiolysis as well as fuel cell experiments to demonstrate the feasibility of increasing the stability of hydrocarbon-based membranes against oxidative attack by implementing a Nature-inspired antioxidant strategy. We found that metalated-porphyrins are suitable for damage transfer and can be used in the fuel cell membrane to reduce membrane aging with a low impact on fuel cell performance.

The Front Cover shows that during the operation of a proton exchange membrane fuel cell harmful radical species (HO⋅, H⋅ and HOO⋅) form that attack the membrane. The use of hydrocarbon-based proton-conducting membranes in fuel cells is currently hampered by the insufficient durability of the material in the device. In our work, we implement a nature-inspired antioxidant strategy by covalently modifying the membrane with metalated porphyrins. Porphyrin-based antioxidants are suitable for transferring damage and thus greatly enhance membrane stability against radical-induced degradation with a minimal impact on fuel cell performance. More information can be found in the Research Article by T. de Wild et al.

Graphene quantum dots are promising candidates for qubits due to weak spin-orbit and hyperfine interactions. The hyperfine interaction, controllable via isotopic purification, could be the key to further improving the coherence. Here, we use isotopically enriched graphite crystals of both $^{12}\mathrm{C}$ and $^{13}\mathrm{C}$ grown by a high-pressure-high-temperature method to exfoliate graphene layers. We fabricated Hall bar devices and performed quantum transport measurements, revealing mobilities exceeding ${10}^{5}\phantom{\rule{4pt}{0ex}}{\text{cm}}^{2}/\text{V}\phantom{\rule{0.16em}{0ex}}\text{s}$ and a long mean free path of microns, which are as high as natural graphene. Shubnikov--de Haas oscillations, quantum Hall effect up to the filling factor of one, and Brown-Zak oscillations due to the alignment of hBN and graphene are observed thanks to the high mobility. These results constitute a material platform for physics and engineering of isotopically enriched graphene qubits.

Graphene quantum dots are promising candidates for qubits due to weak spin-orbit and hyperfine interactions. The hyperfine interaction, controllable via isotopic purification, could be the key to further improving the coherence. Here, we use isotopically enriched graphite crystals of both $^{12}$C and $^{13}$C grown by high-pressure-high-temperature method to exfoliate graphene layers. We fabricated Hall bar devices and performed quantum transport measurements, revealing mobilities exceeding $10^{5}$$\textrm{cm}^{2}/Vs$ and a long mean free path of microns, which are as high as natural graphene. Shubnikov-de Haas oscillations, quantum Hall effect up to the filling factor of one, and Brown-Zak oscillations due to the alignment of hBN and graphene are observed thanks to the high mobility. These results constitute a material platform for physics and engineering of isotopically-enriched graphene qubits.

A method is presented to reduce the required sample size of forensic glass evidence using single pulse analysis and multivariate statistics.

Assistive robotic manipulators are becoming increasingly important for people with disabilities. Teleoperating the manipulator in mundane tasks is part of their daily lives. Instead of steering the robot through all actions, applying self-recorded motion macros could greatly facilitate repetitive tasks. Dynamic Movement Primitives (DMP) are a powerful method for skill learning via teleoperation. For this use case, however, they need simple heuristics to specify where to start, stop, and parameterize a skill without a background in computer science and academic sensor setups for autonomous perception. To achieve this goal, this paper provides the concept of local, global, and hybrid skills that form a modular basis for composing single-handed tasks of daily living. These skills are specified implicitly and can easily be programmed by users themselves, requiring only their basic robotic manipulator. The paper contributes all details for robot-agnostic implementations. Experiments validate the developed methods for exemplary tasks, such as scratching an itchy spot, sorting objects on a desk, and feeding a piggy bank with coins. The paper is accompanied by an open-source implementation at https://github.com/fzi-forschungszentrum-informatik/ArNe

The correlation between non-uniform gas flow patterns in large ablation cells and the resulting elemental fractionation is investigated and compared to two-volume ablation cells.

Hydrocarbon-based materials are of interest as next-generation proton exchange membranes (PEMs) for the polymer electrolyte fuel cell (PEFC). The biggest drawback of aromatic hydrocarbon PEMs is the presence of aromatic groups contained within the polymer, which make these materials susceptible to radical induced degradation reactions.In this work, we test the hypothesis whether transition metal ions, such as Ce(III), can act as a repair agent in hydrocarbon-based membranes by reducing harmful radical intermediates formed during operation. This is tested by performing in situ accelerated stress tests at open circuit voltage with high H 2 and O 2 partial pressures. Membranes with aromatic sulfonate groups are synthesized as these are common constituents in hydrocarbon-based membranes. Two different approaches to incorporate cerium are explored: 1) ionic bonding of Ce(III) to sulfonate groups and 2) covalent attachment through stable complexes of crown ether and Ce(III). We report that, during fuel cell operation, polymer degradation can be significantly reduced by Ce(III) when immobilized in the membrane. Ionic attachment did not yield in the desired repair effect, most likely due to cerium migration effects.

A key factor in the economic efficiency of satellites is their availability in orbit. Replacing standardized building blocks, such as empty fuel tanks or outdated electronic modules, could greatly extend the satellites' lifetime. This, however, requires flexible robots that can locomote on the surface of these satellites for optimal accessibility and manipulation. This paper introduces ReCoBot, a 7-axis walking space manipulator for locomotion and manipulation. The robot can connect to compatible structures with its symmetric ends and provides interfaces for manual teleoperation and motion planning with a constantly changing base and tip. We build on open-source robotics software and easily available components to evaluate the overall concept with an early stage demonstrator. The proposed manipulator has a length of 1.20 m and a weight of 10.4 kg and successfully locomotes over a satellite mockup in our lab environment.

3D printing is nowadays getting more important in industrial production plants, especially in low quantity productions. Currently, almost no printer model for fused filament fabrication (FFF) has the capability to start a new print automatically after the present one is finished. While the printed object is still on the build plate, the printer cannot continue and this is noneconomical. Manual work is required to be able to start a consecutive job. To get one step closer to full automation of the 3D printing process, the removal process should be automated process, for example with robots. This approach presents a method to determine the number, positions and sizes of all printed objects by analyzing the G-code file of the current print job. It is determined wether the objects can be removed by a robotic arm and in which order. Furthermore, a depth camera is used to verify the hypothesis right after the print process is done. The additional verification is necessary to detect possible changes in the printed structures due to errors during the printing process. In the last step the objects are automatically removed by a robot from the build plate.

Here, we introduce a modified ablation cell based on the tube cell design which provides shortest signal durations reported for LA sample introduction.

Here we describe the first study of a nitrogen based inductively coupled plasma mass spectrometry system in conjunction with laser ablation (LA-(N2-ICP)-MS). Therefore, a microwave-sustained, inductively coupled, atmospheric-pressure plasma source was mounted onto the interface of a quadrupole ICP-MS to investigate the capabilities of such an instrument. The proof of concept study was focused on the quantification capabilities of major to trace elements. Therefore, the plasma background species under dry plasma conditions were investigated to identify the most suitable isotopes for the analysis and to describe the newly formed nitrogen plasma interferences. In addition, the instrumental drift was investigated. Selected elements in the reference materials NIST SRM 612 and BCR-2G were quantified using NIST SRM 610 as an external standard and could be determined within the uncertainty of the reference values. Finally, the limits of detection for LA-(N2-ICP)-MS and LA-(Ar-ICP)-MS were compared indicating similar or even lower LODs for most elements using LA-(N2-ICP)-MS. Therefore, a nitrogen plasma source coupled to a mass spectrometer could challenge the argon-sustained ICP-MS in element analysis by overcoming argon interferences and has the potential to reduce the plasma gas expenses significantly.

Additive manufacturing (AM) is increasingly used in production as possibilities like no geometrical constraints, fabrication of complex assemblies in a single piece and fast iteration delivers a huge additional benefit. However, the printing process is still prone to errors, even though the technology is several decades old. Depending on the object and the used material a complex set of parameters have to be chosen to produce a durable object that fulfills the requirements. The errors can occur at any time during the print process so the current state has to be checked regularly. This is currently done manually as only a few printers use sensors for error detection. But most of them only check for hardware faults like axis misalignment or blocked filament flow control. Meanwhile, a lot of research has been done to improve the material, the printer's hardware as well as to detect errors during the printing process. The goal of this publication is to summarize the current state of the art in terms of the error detection aspect. Therefore, we studied multiple techniques to detect errors like using different sensors concepts, classical sensor data processing, and neural networks. Several promising approaches exist, but so far, only a few are currently used in some commercially available printer. As the research continues, further approaches will be developed and might also be considered in production.