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Design Principles for Integrated Ni(-Ru)/Al Reactive Multilayers: From Mechanical Stability to Controlled Heat Release
Item type: Doctoral Thesis
Toncich, Nensi (2026)
In vivo knee joint friction after total knee arthroplasty is highly dynamic and phase-dependent
Item type: Journal Article
Zierke, Julian N.; Moewis, Philippe; Ehrig, Rainald M.; et al. (2026)
Introduction
Natural synovial knee joints exhibit very low friction, enabling efficient long-term function. In contrast, total knee arthroplasty (TKA) introduces artificial articulating surfaces with altered kinematic and tribological conditions. However, how
in vivo
friction evolves across different dynamic activities after TKA remains unclear. The aim of this study was to quantify
in vivo
knee joint friction after TKA and to investigate its relationship with activity-dependent loading conditions and knee joint kinematics.
Methods
In vivo
joint friction was assessed in three subjects with instrumented telemetric knee implants during chair sit, squat, and level walking. Joint contact forces and moments were recorded
in vivo
, while synchronous fluoroscopic imaging was used to determine knee joint kinematics. Loading data were referenced to the instantaneous axis of rotation to calculate frame-by-frame knee joint friction throughout each activity.
Results
In vivo
friction after TKA was highly dynamic and activity-dependent, showing distinct temporal variations across the three different activities. During chair sit and squat, coefficients of friction (µ) of up to approximately 0.15 were observed during loaded flexion and extension phases, consistent with mixed or boundary lubrication regimes reported
in vitro
. In contrast, substantially higher µ values of up to 0.3 during chair sit and 0.43 during gait were observed during low-loading or rapid kinematic transition phases. Peak friction moments reached up to 5.5 Nm during chair sit, 5.0 Nm during squat, and 8.9 Nm during gait. Overall, friction behavior varied substantially throughout the movement cycle and exhibited pronounced phase-dependent and inter-individual variability with peaks during swing phases.
Discussion
These findings demonstrate that
in vivo
knee joint friction after TKA is dynamic, activity- and phase-dependent. The observed friction dynamics illustrate that friction is only partially linked to contact load magnitude, while motion velocity and possible lubrication-related effects may also influence friction. These findings may help improve experimental and computational models used in TKA tribology and implant evaluation.
Usability of Myosuit exosuit and effects of devicemediated rehabilitation on chronic stroke survivors: a non-randomized pilot study
Item type: Journal Article
Doronzio, Stefano; Campagnini, Silvia; Mannini, Andrea; et al. (2025)
Objectives: The aim of this study is to assess the usability of the Myosuit within a chronic stroke survivors’ rehabilitation program and to explore its therapeutic and assistive role on gait, stair negotiation, sit-to-stand transfers, and balance.
Methods: Ten chronic stroke survivors with gait impairments were enrolled. The System Usability Scale (SUS) was the primary outcome of the study; secondary outcomes were the Stroke Self-efficacy Questionnaire (SSEQ), the Short Physical Performance Battery, the 10-meter Walking Test (10mWT), the 2-minute Walking Test (2minWT), and the Stair Climbing Test. Tests were carried out before (T0) and after (T1) the training sessions, with and without the exoskeleton.
Results: The SUS rated poor-to-ok in 30% of the participants, good in 40%, and excellent to best imaginable in 30%. Comparing T1 vs T0, all the functional tests, except stair descending, showed statistically significant improvements without the exoskeleton, and SSEQ did not change significantly. T1 vs T0 comparisons with the exoskeleton showed improvements in all functional tasks, statistically significant for all, except for 2minWT and 10mWT.
Conclusions: This study confirmed the feasibility of a Myosuit-mediated treatment in a sample of chronic stroke survivors. Despite the usability of the wearable robot being generally positively perceived, it varied among users. Furthermore, the Myosuit exhibited both therapeutic and assistive potential in the sample.
Cyberoperationen und Cyberkommando 2040: Forschungsaktivitäten des CSS Cyber Defense Teams
Item type: Book Chapter
Soesanto, Stefan (2025)
Im folgenden Abschnitt des Bulletin 2025 zur schweizerischen Sicherheitspolitik stellt Stefan Soesanto ausgewählte Forschungsprojekte und Publikationen vor. Diese zeigen, wie das Cyber Defense Team am Center for Security Studies (CSS) der ETH Zürich den rasanten technologischen Fortschritt und die Bedrohungen im Cyberraum analytisch begleitet.
Green Chemistry at 25 and beyond
Item type: Journal Article
Suvarna, Manu; Martín Fernández, Antonio José; Vaccaro, Luigi; et al. (2026)
A literature-mining analysis of 25 years of Green Chemistry shows how prevention-based foundations are being enriched by evidence and systems thinking, inviting broader communities to shape the field’s next chapter. For 25 years, Green Chemistry has helped define how the chemical sciences understand and pursue sustainability. This Perspective uses the anniversary as an opportunity for a community-wide reflection on the journal’s evolution through a data-driven analysis of its history, while considering what this trajectory may mean for the future. We analyse the complete publication record using a literature-mining workflow that combines keyword extraction and clustering with experienced human-guided classification, enabling temporal trend analysis and citation-based impact assessment of major research themes. The results provide a data-informed view of the field’s evolution, showing how foundational areas such as catalysis, organic synthesis, and biomass valorisation are increasingly being connected to circularity, electrification, systems thinking, and societal relevance. Mapping research activity against the Twelve Principles of Green Chemistry highlights their enduring relevance and reveals ten actionable directions through which contemporary research is developing and putting their prevention-based logic into practice. Regional analyses further highlight that the journal has become a truly global enterprise with hubs exhibiting a coherent but distinctive picture. More broadly, this work argues that green chemistry should be understood as the mindset for practising chemistry with prevention, evidence, design, efficiency, lifecycle thinking, implementation, and societal contribution in view, while attracting and connecting disciplines.