The rapid emergence of humanoid robots as Physical AI agents is reshaping manufacturing automation, yet the mechanical embodiment layer—particularly precision reducers embedded in joint actuation—remains insufficiently examined in relation to force interaction, learning stability, and long-term deployability. Existing studies largely treat reducers as mature mechanical components evaluated by classical metrics such as stiffness, backlash, and nominal positioning accuracy. This review argues that such a viewpoint is no longer adequate for humanoid robots operating in contact-rich, human-centered manufacturing environments. Precision reducers are reframed as embodiment enablers that directly shape transparency, compliance, safety, thermal sustainability, and the feasibility of Physical AI–driven control and learning. To formalize this perspective, a humanoid-oriented performance framework is introduced, organized around five embodiment properties capturing torque density, backdrivability, compliant interaction, efficiency and thermal behavior, and bidirectional precision. Using this framework, state-of-the-art reducer and transmission archetypes—including harmonic, cycloidal/RV, planetary, tendon-driven, quasi-direct drive, and hybrid variable-impedance architectures—are systematically reviewed and compared. Emphasis is placed on measurement-driven evaluation under cyclic and bidirectional loading, highlighting that static, unidirectional standards such as ISO 9283 are insufficient for certifying humanoid Physical AI systems operating under frequent torque reversal and micro-collision. By synthesizing quantitative evidence, recent experimental studies, and representative humanoid case studies from the 2020s, this review shows that many limitations attributed to control or learning algorithms originate from transmission-induced nonidealities. The findings point toward actuator-level co-design, joint-specific architectures, and standardized dynamic evaluation as prerequisites for manufacturing-ready humanoid robots. Overall, this work positions precision reducers as active determinants of embodied intelligence rather than passive transmission elements, and provides a reference framework to guide future research, benchmarking, and industrial deployment.
This study presents a scalable sequential lithium intercalation exfoliation strategy that significantly enhances the purity, crystallinity, and electrical performance of two-dimensional NbSe2 synthesized from powder precursors. While conventional single-step Li-intercalation methods often lead to partial exfoliation, surface oxidation, and compromised conductivity, the proposed sequential approach enables the progressive removal of oxide-rich residues and promotes the formation of uniform, defect-minimized NbSe2 nanosheets. The resulting material exhibits substantially reduced surface oxide content, improved layer alignment, and achieves up to a similar to 6.5 & times; reduction in electrical resistance with stable performance over 14 days under ambient conditions. In particular, the purified NbSe2 thin films demonstrate a rapid temperature rise to similar to 150 degrees C within similar to 40 s and spatially uniform Joule-heating behavior without localized hotspots, indicating strong potential for use in flexible and reliable thermal management components. Beyond NbSe2, this methodology offers a generalizable route for producing high-quality, conductive TMDC films, thereby addressing persistent challenges in powder-based 2D material processing and supporting their potential integration into advanced nanoelectronic, optoelectronic, and energy-related technologies.
Patients with rheumatoid arthritis have higher fracture risks than those without RA, particularly in seropositive cases. The risk of fractures remained elevated regardless of bDMARD or tsDMARD use, warranting further large-scale studies. Our findings highlight the need for active surveillance and timely intervention in RA patients, particularly those with SPRA and regardless of bDMARD or tsDMARD use. Evidence of the association between the serological status and the risk of fracture among patients with rheumatoid arthritis (RA) considering exposure to disease-modifying antirheumatic drugs (DMARDs) is scarce. We investigated the risk of fracture among patients with RA according to the serological status considering exposures to biologic DMARDs (bDMARDs) or targeted synthetic DMARDs (tsDMARDs). We conducted a population-based retrospective cohort study using the Korean National Health Insurance Service database including patients who were diagnosed with RA between 2010 and 2017 (n = 43,677) and controls matched according to age and sex (n = 131,031). Patients with RA had a higher risk of any fractures compared to matched controls (adjusted hazard ratio [aHR] 1.68, 95
Here we demonstrate that integrating hierarchical energy-level coherence with robust interfacial photophysics enables simultaneous optimization of charge injection, charge transport, and charge recombination in hyperfluorescent (HF) blue-emitting organic light-emitting diodes (OLEDs). A self-assembled hybrid hole-injection layer forms a vertically stratified, dipole-induced interface, and an HF emitting layer (EML) that is composed of a fast triplet-upconverting sensitizer, a high-triplet-energy host, and a narrowband thermally activated delayed fluorescence (TADF) emitter achieves efficient triplet harvesting and singlet-mediated energy transfer. This hierarchical framework ensures smooth charge-carrier propagation, balanced recombination, and strong suppression of interfacial exciton quenching, thereby preserving efficient triplet recirculation even in multilayer architectures. As a result, the blue HF OLED attains a high external quantum efficiency of 44.3%, a narrow emission bandwidth of 19 nm, deep-blue CIE coordinates of (0.104, 0.173), and improved operational stability.
Pulse Width Modulated (PWM) voltage source inverters are widely used to power induction motors in industrial applications. However, they generate common-mode voltage (CMV), which induces high shaft voltages and bearing currents, leading to premature motor failures. This paper proposes a novel active cancellation method to compensate for the CMV in high-voltage induction motor drives. The method utilizes Y-configured resistors for CMV detection and a push-pull amplifier with MOSFETs to generate reproduced CMV (RCMV). The RCMV is applied to the motor frame via an isolation transformer, effectively reducing the CMV-induced common-mode current (CMC). The proposed method achieves a significant reduction in the CMC, from 1.5 A to 4 mA peak-to-peak in a simulation and from 2.7 A to 57 mA peak in experiments with a 1.1 kW, 415 V/60 Hz motor. This cost-effective approach enhances motor drive reliability and mitigates electromagnetic interference (EMI), making it suitable for high-voltage applications.
