Wearable devices demand components that are not only flexible but stretchable to an exceptional degree, seamlessly integrating with the dynamic movements of the wearer. Traditional wiring and interconnect technologies have long struggled to accommodate this need due to limitations in material flexibility, stretchability, and interface reliability. The novel three-dimensional cable presented by Wu, Jia, Li, and their team transcends these barriers by combining a core–shell architecture that is both mechanically robust and electrically conductive, all while being recyclable and compatible with scalable manufacturing techniques.

At the heart of this innovation lies a stretchable cable with a Young’s modulus of approximately 0.9 MPa, which situates it firmly within the soft material regime, facilitating natural movement without causing discomfort or damage to the device or wearer. Remarkably, the cable exhibits a maximum stretchability nearing 800%, a feature that allows it to undergo substantial elongation without compromising its function. This elasticity is particularly vital for applications in wearable physiological monitoring, where the cable must respond resiliently to body movement without signal degradation.

Resistance stability under strain is a notable hallmark of the core–shell cable. Conventional stretchable conductors typically experience increased electrical resistance as they are elongated, resulting in signal noise and reduced reliability. In contrast, the cable developed here demonstrates almost negligible resistance change even when stretched to its maximum capacity. This attribute is instrumental in maintaining the fidelity of signals, which is essential for sensitive physiological monitoring and other precise electronic measurements.

The cable’s core–shell design contributes significantly to its enhanced durability and electrical performance. The inner core, responsible for electrical conduction, is encapsulated by a stretchable shell that provides mechanical integrity and protection from environmental factors. This configuration not only prolongs the lifespan of the cable but also minimizes mechanical interference effects that commonly plague stretchable electronic interconnects.

Addressing the practicalities of device integration, the researchers devised a room-temperature connection process that enables the cables to form reliable and robust interfaces with various conductive pads. This approach eliminates the need for high-temperature soldering, which can damage sensitive components or substrates and limits the scope of materials that can be joined. The compatibility with low-temperature processing broadens the cable’s applicability across diverse electronic platforms, ranging from soft, flexible substrates to rigid circuit boards.

Moreover, the stretchable cable is patternable, enabling precise and customizable cable geometries that can be tailored to the specific requirements of different devices and applications. This feature not only supports mass manufacturing but also facilitates the creation of complex circuitry layouts that retain mechanical resilience, a crucial step towards the commercialization of soft wearable electronics.

Equally impressive is the high recycling rate of the cable’s manufacturing process, reaching up to 95%. Sustainability is an increasingly critical aspect of materials development, particularly in consumer electronics, where rapid obsolescence and disposal contribute to environmental burden. By integrating recyclability without compromising performance, this technology sets a new standard for responsible innovation in stretchable electronics.

In practical demonstration, the stretchable core–shell cables were used to construct hybrid electronic systems that maintained electrical performance under extensive mechanical stretching. These hybrid systems blend soft and rigid electronic components, a combination traditionally difficult to interconnect stably due to mismatched mechanical properties. The core–shell cables harmonize these disparate elements into cohesive devices capable of enduring real-world wearable scenarios.

The reliability of the cable under mechanical interference extends beyond mere stretching; it also exhibits resistance to noise induced by motion artifacts and external environmental disturbances. This makes it particularly suitable for physiological monitoring, where accurate signal acquisition amidst daily activity-induced noise is paramount. The prospect of wearable health devices delivering consistent and accurate data brings immense potential for personalized medicine and continuous health monitoring.

Underlying the success of this technology is a fabrication process that is versatile across multiple scales. From microfabricated sensors to larger wearable platforms, the compatibility of the cable’s production with existing manufacturing infrastructures promises feasible integration into existing supply chains. This scalability is key for transitioning from laboratory prototypes to commercially viable products.

The impact of this development extends beyond wearables to encompass soft robotics, implantable devices, and flexible displays. Any device demanding mechanically compliant but electrically reliable interconnects stands to benefit from the three-dimensional stretchable core–shell cable. By resolving the persistent challenge of creating stretchable cables that combine reliability, ease of patterning, and sustainability, this technology charts a course for the next generation of soft electronics.

Looking forward, the potential to integrate this cable technology with emerging conductive materials such as liquid metals, nanowires, or conductive polymers could further enhance its performance envelope. Additionally, ongoing work to refine the interfacial chemistry and mechanical properties may pave the way for even greater stretchability and durability.

In summary, the introduction of this three-dimensional stretchable core–shell cable represents a seminal step forward in soft and hybrid electronics. Its unique confluence of exceptional mechanical properties, electrical stability, patternability, recyclability, and noise resistance addresses several critical pain points in wearable and flexible electronics design. As these cables begin to find their way into next-generation devices, they promise to unlock new possibilities for seamless human-technology integration, embedded health monitoring, and beyond.

Subject of Research: Stretchable core–shell cables for wearable and hybrid soft electronics

Article Title: A three-dimensional stretchable core–shell cable for soft and hybrid electronics that is patternable, recyclable and noise-resistant

Article References:
Wu, P., Jia, S., Li, J. et al. A three-dimensional stretchable core–shell cable for soft and hybrid electronics that is patternable, recyclable and noise-resistant. Nat Electron (2026). https://doi.org/10.1038/s41928-026-01596-2

Image Credits: AI Generated

DOI: https://doi.org/10.1038/s41928-026-01596-2

Addressing these challenges, an innovative research team led by Professor Keun Park and Associate Professor Soonjae Pyo at Seoul National University of Science and Technology has pioneered the fabrication of highly stretchable and electrically conductive CNT nanocomposites using vat photopolymerization (VPP)-based additive manufacturing. VPP is a sophisticated 3D printing technique that leverages selective light curing within a resin vat to create finely detailed, complex structures. The researchers expertly overcame traditional issues related to CNT agglomeration and ink curing, achieving a formidable balance between stretchability, conductivity, and print resolution—factors that usually exhibit trade-offs in composite materials.

The core strategy employed involved dispersing multi-walled carbon nanotubes (MWCNTs) within an aliphatic urethane diacrylate (AUD) photopolymer matrix. This required meticulous ultrasonic agitation to achieve a homogeneous mixture, which is essential for ensuring consistent electrical pathways and mechanical reinforcement throughout the printed material. Ranging from 0.1 to 0.9 weight percent MWCNTs, the polymer nanocomposite inks were rigorously evaluated to determine optimal properties for 3D printing, including viscosity, curing kinetics, and compatibility with VPP’s photopolymerization process.

Key to their breakthrough was the identification of the 0.9 weight percent MWCNT concentration as the sweet spot that balanced conductivity and mechanical resiliency. Test specimens exhibited remarkable stretchability, enduring elongations up to 223% of their original length without failure, an exceptional value that far exceeds typical CNT nanocomposite performance benchmarks. Concurrently, the electrical conductivity reached an impressive 1.64 × 10^−3 S/m, surpassing earlier reports of similar 3D printable composite materials. This dual achievement of high stretchability and conductivity while maintaining a print resolution of 0.6 mm signifies a new frontier in material science and engineering.

Leveraging the optimized nanocomposite formulations, the team fabricated triply periodic minimal surface (TPMS) structures—complex 3D lattice geometries known for their outstanding mechanical properties and lightweight architectures. These structures functioned as piezoresistive sensors characterized by high sensitivity to mechanical deformation, which is vital for accurate detection of pressure and strain in wearable devices. Incorporating these sensors into a flexible insole demonstrated practical application potential, whereby the pressure distribution exerted by a user’s foot could be monitored in real time. This capability paves the way for advanced health monitoring systems that can detect gait anomalies or postural changes with high spatial and temporal resolution.

The integration of the CNT-based piezoresistive sensors into wearable platforms, such as smart insoles, embodies the intersection of materials innovation and human-centric design. The use of additive manufacturing allows for the precise tailoring of sensor architectures, enabling bespoke designs optimized for sensitivity, durability, and wearer comfort. Moreover, the piezoresistive effect in CNT nanocomposites offers a promising alternative to conventional rigid sensors, which often suffer from limited flexibility and poor adaptability to dynamic human motion.

Beyond the sensor application, the researchers underscore the broader implications of their work for fields ranging from soft robotics to smart textiles. The tailored VPP-based synthesis of CNT nanocomposites can lead to next-generation electronic components that combine mechanical compliance with conductive functionality, a crucial requirement for devices embedded in flexible and deformable substrates. This advance fundamentally changes how we conceive the design and manufacture of wearable health monitors by integrating sensing capabilities directly into customized 3D-printed form factors.

While prior approaches struggled with CNT dispersion and UV-light induced curing limitations, this study’s methodical optimization allowed the preservation of photopolymerization efficiency despite the presence of electrically conductive fillers. The ultrasonication technique effectively broke down CNT bundles, facilitating homogenous dispersion and minimizing light scattering during the VPP curing process. This breakthrough enables a radical enhancement in print fidelity for complex geometries, pushing the envelope of what additive manufacturing can achieve with multifunctional nanocomposites.

This development arrives at a time when the demand for wearable health devices is surging, fueled by the growing population of health-conscious and aging individuals. The ability to manufacture stretchable, conductive, and highly sensitive sensors affordably and at scale could democratize advanced healthcare monitoring, providing continuous, real-time data to both patients and healthcare providers. This would allow early detection of abnormalities and personalized interventions outside clinical settings, significantly impacting patient outcomes and healthcare economics.

Professor Keun Park emphasizes that their optimized CNT nanocomposites are not only suited for piezoresistive sensor fabrication but also open avenues for creating architectured materials with tunable mechanical and electrical properties. Such materials can be tailored to specific application requirements, enhancing the functionality and integration capacity of flexible devices. The research demonstrates critical progress in the feasibility of 3D printing these complex materials in forms that were previously impossible due to material or process constraints.

Associate Professor Soonjae Pyo highlights the multidisciplinary synergy required to realize these advancements, combining expertise in nanoscale material science, additive manufacturing technology, and sensor engineering. Their collaborative efforts embody the future trajectory of materials innovation, where precise control at multiple length scales—from molecular dispersion of CNTs to large-scale device architecture—enables transformative device capabilities.

The significance of this study extends beyond academia, potentially impacting industries such as healthcare, consumer electronics, athletics, and even aerospace, where lightweight, multifunctional, and flexible materials are in high demand. The scalable VPP-based process for these CNT nanocomposites also implies cost-effective manufacturability, critical for commercial viability. As flexible and wearable electronics continue to push boundaries, the materials enabling these devices must evolve. This research provides a key technological leap, signaling a paradigm shift in how conductive, stretchable materials are created and utilized.

In summary, the team at Seoul National University of Science and Technology has successfully demonstrated a photopolymerization additive manufacturing method that fabricates highly stretchable, electrically conductive CNT nanocomposites with exceptional mechanical and electrical performance. Their ability to create complex, architectured sensors using 3D printing marks a significant advancement in wearable technology. By embedding these sensors into smart insoles capable of real-time pressure monitoring, they exemplify the practical impact and transformative potential of their materials innovation. As the field advances, such breakthroughs will undoubtedly accelerate the development of next-generation smart, flexible devices vital for personalized health monitoring and beyond.

Subject of Research: Not applicable

Article Title: Photopolymerization additive manufacturing of highly stretchable CNT nanocomposites for 3D-architectured sensor applications

News Publication Date: 15-Nov-2025

References: DOI: 10.1016/j.compstruct.2025.119614

Image Credits: Seoul National University of Science and Technology

Keywords: Nanotechnology, Additive manufacturing, Carbon nanotubes, Conductive polymers, Wearable devices, Health and medicine, Sensors, Materials science