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1. Programming Magnetic Composites and Phase Change Materials for Multimodal Haptic Interfaces with Integrated Self-Sensing toward Adaptive and Proprioceptive Haptic Feedback

   https://doi.org/10.1039/D5MH01998B  

   Yao, Shanshan; Chen, Si; Li, Su; Li, Yizong; Dong, Penghao (February 2026, Materials Horizons)

   Advancements in wearable human–machine interfaces require haptic systems that are mechanically compliant, functionally versatile, and capable of delivering rich tactile and proprioceptive feedback under varying interaction conditions. However, existing haptic devices are often constrained by bulky structures, rigid components, insufficient actuation modalities, and the absence of self-sensing capabilities, which restrict their wearability, responsiveness, robustness, and seamless integration with the human body. This work presents multimodal, self-sensing haptic interfaces enabled by programmable soft magnetic composites and phase change materials, which provide three distinct working modes (normal, rotational shear, and skin stretch) within a compact, skin-conformal form factor. The haptic interface leverages soft magnets with programmable magnetization profiles to enable multimodal actuation. Hybrid electromagnetic coils, incorporating both solenoid and planar configurations fabricated with stretchable gallium-based conductors, are designed to enhance stretchability and actuation output. Combined with a Kirigami-patterned elastomeric spring, the haptic actuator generates forces and displacements that exceed human tactile perception thresholds while maintaining performance under deformation. Furthermore, the inductance-based self-sensing mechanism provides real-time displacement monitoring for closed-loop control, ensuring consistent performance across varying actuation and interaction conditions. Ultimately, our soft multimodal haptic device can facilitate selective stimulation of multiple cutaneous mechanoreceptors and has been demonstrated to accurately encode both limb spatial position and joint motion for comprehensive proprioceptive feedback. 

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2. Soft Growing Pin for High-Extension Shape-Changing Displays

   https://doi.org/10.1109/RoboSoft60065.2024.10522001  

   Valdivia, Antonio Alvarez; Rezqalla, Mohammad A; Swann, Sarah E; Blumenschein, Laura H (April 2024, IEEE)

   Regular user interface screens can display dense and detailed information to human users but miss out on providing somatosensory stimuli that take full advantage of human spatial cognition. Therefore, the development of new haptic displays can strengthen human-machine communication by augmenting visual communication with tactile stimulation needed to transform information from digital to spatial/physical environments. Shape-changing interfaces, such as pin arrays and robotic surfaces, are one method for providing this spatial dimension of feedback; however, these displays are often either limited in maximum extension or require bulky mechanical components. In this paper, we present a compact pneumatically actuated soft growing pin for inflatable haptic interfaces. Each pin consists of a rigid, air-tight chamber, an inflatable fabric pin, and a passive spring-actuated reel mechanism. The device behavior was experimentally characterized, showing extension to 18.5 cm with relatively low pressure input (1.75 psi, 12.01 kPa), and the behavior was compared to the mathematical model of soft growing robots. The results showed that the extension of the soft pin can be accurately modeled and controlled using pressure as input. Finally, we demonstrate the feasibility of implementing individually actuated soft growing pins to create an inflatable haptic surface. 

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3. Magnetic domains and domain wall pinning in atomically thin CrBr3 revealed by nanoscale imaging

   https://doi.org/10.1038/s41467-021-22239-4  

   Sun, Qi-Chao; Song, Tiancheng; Anderson, Eric; Brunner, Andreas; Förster, Johannes; Shalomayeva, Tetyana; Taniguchi, Takashi; Watanabe, Kenji; Gräfe, Joachim; Stöhr, Rainer; et al (December 2021, Nature Communications)

   null (Ed.)

   Abstract The emergence of atomically thin van der Waals magnets provides a new platform for the studies of two-dimensional magnetism and its applications. However, the widely used measurement methods in recent studies cannot provide quantitative information of the magnetization nor achieve nanoscale spatial resolution. These capabilities are essential to explore the rich properties of magnetic domains and spin textures. Here, we employ cryogenic scanning magnetometry using a single-electron spin of a nitrogen-vacancy center in a diamond probe to unambiguously prove the existence of magnetic domains and study their dynamics in atomically thin CrBr 3 . By controlling the magnetic domain evolution as a function of magnetic field, we find that the pinning effect is a dominant coercivity mechanism and determine the magnetization of a CrBr 3 bilayer to be about 26 Bohr magnetons per square nanometer. The high spatial resolution of this technique enables imaging of magnetic domains and allows to locate the sites of defects that pin the domain walls and nucleate the reverse domains. Our work highlights scanning nitrogen-vacancy center magnetometry as a quantitative probe to explore nanoscale features in two-dimensional magnets. 

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4. Handheld Haptic Device with Coupled Bidirectional Input

   Doshi, M. V.; Hagenow, M.; Radwin, R.; Gleicher, M.; Mutlu, B.; Zinn, M. (January 2023, IEEE World Haptics Conference)

   Handheld kinesthetic haptic interfaces can provide greater mobility and richer tactile information as compared to traditional grounded devices. In this paper, we introduce a new handheld haptic interface which takes input using bidirectional coupled finger flexion. We present the device design motivation and design details and experimentally evaluate its performance in terms of transparency and rendering bandwidth using a handheld prototype device. In addition, we assess the device's functional performance through a user study comparing the proposed device to a commonly used grounded input device in a set of targeting and tracking tasks. 

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5. Noncentrosymmetric Triangular Magnet CaMnTeO ₆ : Strong Quantum Fluctuations and Role of s ⁰ versus s ² Electronic States in Competing Exchange Interactions

   https://doi.org/10.1002/adma.202313763  

   Huai, Xudong; Acheampong, Emmanuel; Delles, Erich; Winiarski, Michał J; Sorolla, Maurice; Nassar, Lila; Liang, Mingli; Ramette, Caleb; Ji, Huiwen; Scheie, Allen; et al (June 2024, Advanced Materials)

   Abstract Noncentrosymmetric triangular magnets offer a unique platform for realizing strong quantum fluctuations. However, designing these quantum materials remains an open challenge attributable to a knowledge gap in the tunability of competing exchange interactions at the atomic level. Here, a new noncentrosymmetric triangularS = 3/2 magnet CaMnTeO₆is created based on careful chemical and physical considerations. The model material displays competing magnetic interactions and features nonlinear optical responses with the capability of generating coherent photons. The incommensurate magnetic ground state of CaMnTeO₆with an unusually large spin rotation angle of 127°(1) indicates that the anisotropic interlayer exchange is strong and competing with the isotropic interlayer Heisenberg interaction. The moment of 1.39(1) µB, extracted from low‐temperature heat capacity and neutron diffraction measurements, is only 46% of the expected value of the static moment 3 µB. This reduction indicates the presence of strong quantum fluctuations in the half‐integer spinS = 3/2 CaMnTeO₆magnet, which is rare. By comparing the spin‐polarized band structure, chemical bonding, and physical properties of AMnTeO₆(A = Ca, Sr, Pb), how quantum‐chemical interpretation can illuminate insights into the fundamentals of magnetic exchange interactions, providing a powerful tool for modulating spin dynamics with atomically precise control is demonstrated. 

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