Wearable sensing technologies are rapidly emerging as essential tools for continuous health monitoring in daily life. Textiles, being in direct and constant contact with the human body, provide an ideal platform for integrating such sensing functions. For sensorized garments to be suitable for home monitoring, they must meet strict requirements in terms of unobtrusiveness and user comfort. Conventional e-textile approaches that rely on rigid electronic components or laminated films often compromise garment breathability, flexibility, and softness, leading to user discomfort and reduced wearability. This work presents an alternative approach to electronic textiles (e-textiles), in which sensing capabilities are derived directly from the structure, orientation, and interconnection of conductive yarns integrated within the fabric. The proposed concept leverages the inherent properties of textiles-softness, flexibility, and comfort-while enabling multifunctional sensing without the need for bulky or rigid components. The design focuses on the three-dimensional textile architecture to engineer reliable and accurate sensing surfaces. Conductive yarns can be knitted, woven or embroidered to function as capacitive or resistive elements, enabling the detection of parameters such as pressure, strain, and moisture. Furthermore, arrays of conductive yarns can be configured to form capacitive touch sensors or humiditysensing grids. Power supply and data acquisition units remain external but can be positioned in unobtrusive locations to preserve wearer comfort. We present several examples of functional textile sensors, including woven, knitted, and embroidered configurations. By employing computerized textile manufacturing techniques, accurate, reproducible, and durable sensors can be realized while maintaining textile comfort and aesthetics. The elimination of rigid or laminated components further enhances washability and long-term reliability under realworld conditions.

Liquid crystal elastomer (LCE) fiber actuators are promising candidates for smart textiles owing to their reversible large-stroke actuation and high aspect ratios. However, current LCEs require ultraviolet (UV) curing and are not recyclable. In addition, research is mainly focused on flat knitted thermo-responsive textiles. Here, a scalable recycling route for smart LCE textiles is developed by melt-extruding a thermoplastic LCE containing a near-infrared photothermal dye. The LCE fibers exhibit ∼30% reversible actuation strain and display light-driven rolling motions with left- or right-turning trajectories according to their programmed twist handedness. Using commercial knitting machines, multi-material plain- and rib-knit textiles are fabricated that exhibit in-plane contraction and out-of-plane deformations including bending and twisting under thermal and photo stimuli. Circularly knitted tubular structures exhibit reversible contraction in both radial and axial directions, reaching approximately 16% in outer diameter, 19% in inner diameter, and 14% in length, enabling applications in autonomous climbing, controlled liquid release, and micro pumping. Finally, thermo-mechanical recycling yields recycled fibers and both flat and circularly knitted textile structures with nearly unchanged actuation performance and comparable mechanical properties, demonstrating robust recyclability. Our results demonstrate the creation of smart textiles that are simultaneously intelligent in function and sustainable in design.

Conventional hinge actuators often face limitations including excessive weight, large size and unpleasant noise. Shape memory alloys (SMAs) offer a solution to address these issues due to their favorable characteristics, such as lightweight, high actuation force and small form factor. However, most existing SMA-based hinge actuators rely on the tension loading mode. Achieving an ideal actuation angle thereby necessitates the inclusion of long SMA wires, which inadvertently constrains the actuator size. Notably, the full potential of SMAs’ deformation capacities, encompassing torsion and bending, remains largely untapped and underutilized. In this research, a reversible torsion SMA hinge actuator is studied, which can reversibly open 60° during heating and cooling. The actuator weighs 2 g, and can produce actuation forces of up to 5 N. The mechanical performances of nitinol at different temperatures are measured. Based on the measurements, a model which can predict the opening and closing angle is proposed, with deviations of 13.5 ± 8.2 %. Gripper and butterfly demonstrators constructed by the hinge actuators are given as application examples. The actuators hold potential in many fields like soft robotics, aerospace and medical instruments.

The paper explores the potential applications of adaptive components based on shape memory polymer (SMP) composites in vibration control of plate/shell structures and rigidization of inflatable structures. These components achieve stiffness and damping variation by thermally actuating SMP between its glassy and rubbery states. In CASE A, steel-SMP sandwich plates of a truss bridge are actuated to glass transition temperature (Tg), where material damping reaches the peak to mitigate dynamic responses. CASE B proposes a simple and reversible rigidization method for inflatable structures, creating high compaction ratio and design flexibility. Converting the SMP layer between its glassy and rubbery states, inflatable structures achieve multiple functions during transportation, construction, and service life. SMP-based adaptive components enhance structural performance and mitigate dynamic effects in demanding environments for various structures.

We developed a shape-changing constructive kit, named Mimosa1. A key component of the toolkit is the modular hinges, each of which is equipped with two antagonistic shape memory alloy (SMA) wires. One wire deforms the hinge to approach its predetermined angle at high temperature, and another wire drives the hinge back when it cools down. Hinge leaves are available in different materials including acrylic, cardboard and textile, which increases the versatility of the toolkit. Every hinge weighs 2.1-5.4 g, and generates up to 5.7 N actuation force. A Bluetooth control module was developed, enabling remote control of the shape-changing objects. Mimosa aims to inspire designers to explore and create interactive shape-morphing objects with SMAs. A few examples are given such as a gripper, a rolling robot, a butterfly, an airplane and a self-closing pocket. A workshop study with 6 participants showed that Mimosa indeed motivated and inspired the participants to create new ideas.

Constructing lunar bases is crucial as lunar missions progress towards utilization and exploitation. The challenging lunar environment, with its unique characteristics and limited resources, requires special materials, structures, and construction methods. Inflatable structures offer great potential for lunar construction due to their advantages in transportation, stowage, construction, and reliability. This paper proposes a rigidizable inflatable lunar habitat that maintains its shape even after air leakage, enhancing safety, durability, and fixability. The membrane material adapts to different requirements during transportation, construction, and service, achieved through solid-state actuation of shape memory polymer (SMP) for stiffness variation, allowing multiple moves and ground tests. This work comprises three parts: 1) system: design concept and construction processes, 2) material: design and characterization of restraint and rigidization materials, and 3) structure: numerical validation of structure properties. Finite element analysis, based on material models obtained through dynamic mechanical analysis (DMA) and tensile tests, demonstrates the effectiveness of including an SMP rigidization layer in preventing collapse and enhancing dynamic properties. This paper not only proposes a new system, but also provides material design methods and requirements, along with structural validation techniques. Findings validate the feasibility of rigidizable inflatable lunar habitats, applicable in extreme environments, also in temporary buildings, space structures, and soft robotics.

As an emerging technology, smart textiles have attracted attention for rehabilitation purposes or to monitor heart rate, blood pressure, breathing rate, body posture, as well as limb movements. Traditional rigid sensors do not always provide the desired level of comfort, flexibility, and adaptability. To improve this, recent research focuses on the development of textile-based sensors. In this study, knitted strain sensors that are linear up to 40% strain with a sensitivity of 1.19 and a low hysteresis characteristic were integrated into different versions of wearable finger sensors for rehabilitation purposes. The results showed that the different finger sensor versions have accurate responses to different angles of the index finger at relaxation, 45° and 90°. Additionally, the effect of spacer layer thickness between the finger and sensor was investigated.

As an emerging technology, smart textiles have attracted attention for rehabilitation purposes to monitor heart rate, blood pressure, breathing rate, body posture and limb movements. Compared with traditional sensors, knitted sensors constructed from conductive yarns are breathable, stretchable and washable, and therefore, provide more comfort to the body and can be used in everyday life. In this study, knitted strain sensors were produced that are linear with up to 40% strain, sensitivity of 1.19 and hysteresis of 1.2% in absolute values, and hysteresis of 0.03 when scaled to the working range of 40%. The developed sensor was integrated into a wearable wrist-glove system for finger and wrist monitoring. The results show that the wearable was able to detect different finger angles and positions of the wrist.

Sharing breathing signals has the capacity to provide insights into hidden experiences and enhance interpersonal communication. However, it remains unclear how the modality of breath signals (visual, haptic) is socially interpreted during collaborative tasks. In this mixed-methods study, we design and evaluate BreatheWithMe, a prototype for real-time sharing and receiving of breathing signals through visual, vibrotactile, or visual-vibrotactile modalities. In a within-subjects study (15 pairs), we investigated the effects of modality on breathing synchrony, social presence, and overall user experience. Key findings showed: (a) there were no significant effects of visualization modality on breathing synchrony, only on deliberate music-driven synchronization; (b) visual modality was preferred over vibrotactile feedback, despite no differences across social presence dimensions; (c) BreatheWithMe was perceived to be an insightful window into others, however included data exposure and social acceptability concerns. We contribute insights into the design of multi-modal real-time breathing visualization systems for colocated, collaborative tasks.

Devices delivering sophisticated and natural haptic feedback often encompass numerous mechanical elements, leading to increased sizes and wearability challenges. Shape memory alloys (SMAs) are lightweight, compact, and have high power-to-weight ratios, and thus can easily be embedded without affecting the overall device shapes. Here, a review of SMA-based haptic wearables is provided. The article starts with an introduction of SMAs, while incorporating analyses of relevant devices documented in the literature. Haptic and SMA materials fields are correlated, with haptic perception insights aiding SMA actuator design, and distinct SMA mechanisms offering diverse haptic feedback types. A design process for SMA haptic wearables is proposed based on material-centered approach. We show SMAs hold potential for haptic devices aiding visually impaired people and promise in immersive technology and remote interpersonal haptic communication.

Tailoring the order in hierarchical structures is a key goal of bioinspired nanocomposite design. Recently, nacre-like materials have been developed by solvent evaporation methods that are scalable and attain advanced functionalities. However, understanding the alignment mechanisms of 2D fillers, nanosheets, or platelets remains challenging. This work explores possible pathways for nanocomposite ordering via orientation distribution functions. We demonstrate how the immobilization of 2D materials via (pseudo)network formation is crucial to alignment based on evaporation. We show a modified affine deformation model that describes such evaporative methods. In this, a gel network develops enough yield stress and uniformly deforms as drying proceeds, along with the immobilized particles, causing an in-plane orientation. Herein, we tested the dominance of this approach by using a thermo-reversible gel for rapid montmorillonite (MMT) particle fixation. We researched gelatin/MMT as a model system to investigate the effects of high loadings, orientational order, and aspect ratio. The nacre-like nanocomposites showed a semiconstant order parameter (⟨P₂⟩ ∼ 0.7) over increasing nanofiller content up to 64 vol % filler. This remarkable alignment resulted in continuously improved mechanical and water vapor barrier properties over unusually large filler fractions. Some variations in stiffness and diffusion properties were observed, possibly correlated to the applied drying conditions of the hybrid hydrogels. The affine deformation strategy holds promise for developing next-generation advanced materials with tailored properties even at (very) high filler loadings. Furthermore, a gelling approach offers the advantages of simplicity and versatility in the formulation of the components, which is useful for large-scale fabrication methods.

PURPOSE: For wheelchair users with a spinal cord injury, the lower body may be a more convenient cooling site than the upper body. However, it remains unknown if leg cooling reduces thermal strain in these individuals. We compared the impact of upper-body versus lower-body cooling on physiological and perceptual outcomes during submaximal arm-crank exercise under heat stress in individuals with paraplegia. METHODS: Twelve male participants with paraplegia (T4-L2, 50% complete lesion) performed a maximal exercise test in temperate conditions, and three heat stress tests (32°C, 40% relative humidity) in which they received upper-body cooling (COOL-UB), lower-body cooling (COOL-LB), or no cooling (CON) in a randomized counterbalanced order. Each heat stress test consisted of four exercise blocks of 15 min at 50% of peak power output, with 3 min of rest in between. Cooling was applied using water-perfused pads, with 14.8-m tubing in both COOL-UB and COOL-LB. RESULTS: Gastrointestinal temperature was 0.2°C (95% confidence interval (CI), 0.1°C to 0.3°C) lower during exercise in COOL-UB versus CON (37.5°C ± 0.4°C vs 37.7°C ± 0.3°C, P = 0.009), with no difference between COOL-LB and CON ( P = 1.0). Heart rate was lower in both COOL-UB (-7 bpm; 95% CI, -11 to -3 bpm; P = 0.01) and COOL-LB (-5 bpm; 95% CI, -9 to -1 bpm; P = 0.049) compared with CON. The skin temperature reduction at the cooled skin sites was larger in COOL-LB (-10.8°C ± 1.1°C) than in COOL-UB (-6.7°C ± 1.4°C, P < 0.001), which limited the cooling capacity in COOL-LB. Thermal sensation of the cooled skin sites was improved and overall thermal discomfort was lower in COOL-UB ( P = 0.01 and P = 0.04) but not in COOL-LB ( P = 0.17 and P = 0.59) compared with CON. CONCLUSIONS: Upper-body cooling more effectively reduced thermal strain than lower-body cooling in individuals with paraplegia, as it induced greater thermophysiological and perceptual benefits.