Achieving high mechanical stretchability while maintaining charge carrier mobility in semiconducting polymers remains a central challenge due to their intrinsic trade-off. Conjugated multiblock copolymers (CMPs) incorporating semiconducting and elastomeric segments represent a promising design strategy to overcome this limitation, yet a systematic understanding of how structural parameters influence material properties and device performances is still lacking. To address this issue, we chose a model polymer, poly(3-hexylthiophene) (P3HT), and systematically constructed its library precursors with independently varied molecular weight, dispersity, and end-group fidelity. Then, these precursors were incorporated into CMPs containing flexible polydimethylsiloxane (PDMS) over a broad composition range (0-75 mol%). As a result, this design enabled deconvolution of the individual effects of each structural parameter on CMP performance. Notably, CMPs incorporating well-defined P3HT blocks exhibited significantly enhanced stretchability (>300%) while retaining high hole mobility, in contrast to those prepared using P3HT from uncontrolled polymerization. These results underscore the advantage of living polymerization in precisely tailoring conjugated polymer architectures and optimizing the mechanical and electronic properties of stretchable semiconducting materials, while also offering a platform that may be extended to other conjugated polymers.

ABSTRACT The growing demand for wearable sensors and skin‐mounted electronics has accelerated the development of flexible and stretchable batteries that can operate safely under mechanical deformation and physiological conditions. However, achieving both high electrochemical performance and intrinsic safety in such systems remains a major challenge. Previous review articles have focused on the classification of individual battery components such as electrodes, electrolytes, and current collectors, with emphasis on improving mechanical flexibility and stretchability. Here, this review summarizes the key design safety factors when a battery development considers various materials, structural deformability, biocompatibility, and self‐protection mechanisms. This article highlights how safety can be systematically embedded in a flexible and stretchable platform and analyzes the comprehensive design relationships among material composition, structural geometry, biocompatibility, and self‐regulating protection that collectively determine electrochemical and physiological stability under multi‐modal deformation. Finally, perspectives are provided for developing intrinsically safe, human‐compatible, and sustainable energy systems toward next‐generation wearable electronics.

ABSTRACT Advancing free‐form‐factor electronics is essential to broaden their applicability of electronics. In this regard, the development of stretchable semiconductors and their systems that offer both excellent stretchability with outstanding optoelectronic properties is imperative. Among various optoelectronic material candidates, metal‐halide perovskite has emerged as the most promising semiconductors owing to their high charge mobility, long exciton diffusion length and tunable bandgap. However, compared to stretchable organic‐based devices, stretchable perovskite devices have been rarely investigated because of perovskites’ inherently low mechanical stretchability. In this regard, to develop stretchable perovskite optoelectronics, identifying the fundamental determinants of their low mechanical deformability and establishing of strategies to overcome these limitations are crucial. In this context, this paper presents the first in‐depth overview of stretchability characteristics of perovskite‐based optoelectronic device, highlighting key strategies for realizing next‐generation stretchable platforms from material and geometric perspectives. In detail, background on mechanical deformation behaviors of stretchable devices is provided. Subsequently, we examine reported studies on stretchable perovskite optoelectronic devices according to their materials and device structures. Finally, current challenges and important issues that remain unresolved but must be addressed to enable meaningful progress are discussed.

AI-enhanced diagnosis of atrial arrhythmia using 3D-printed origami ECG sensors.

Inspired by the brain's parallel and energy-efficient processing, research into neuromorphic computing chips has increasingly explored the integration of thin-film transistors (TFTs) as artificial neuron-like elements, owing to their intrinsic three-terminal architecture, which enables synaptic behavior, low-power switching, and scalable integration for high-performance electronic systems. As research advances from individual device functionality toward system-level implementation, TFT-based neuromorphic computing and logic circuits have emerged as promising platforms for next-generation electronics, including wearable and implantable devices, neuromorphic components such as artificial synapses and electronic skin, and integrated logic architectures. To realize these TFT-based circuits, selecting materials with appropriate electrical properties is essential, and single-walled carbon nanotubes (SWCNTs) offer notable advantages over leading commercial backplane semiconductors: they exhibit ∼10× higher carrier mobility than IGZO, a representative oxide semiconductor widely used in high-end TV displays; ∼300× faster logic switching than conventional oxide TFTs, widely employed in advanced display systems; and subnanosecond signal delays at battery-compatible voltages (∼2.6 V), in contrast to the 10-15 V required for IGZO and ∼3 V for polycrystalline silicon, the prevalent choice in high-performance mobile displays. These electronic advantages are complemented by low-power consumption, excellent mechanical flexibility and stretchability, intrinsic biocompatibility, and the potential for large-area integration. Despite these promising attributes, the current SWCNT TFT technology ecosystem remains largely at Technology Readiness Levels 3-5, with most demonstrations limited to proof-of-concept devices and laboratory-scale prototypes, despite recent milestones such as semiconducting purities exceeding 99.9999%, scalable roll-to-roll processing, and high-density integration. In this Perspective, a strategic perspective is presented on advancing SWCNT TFTs from laboratory-scale innovations to scalable, industry-relevant platforms for neuromorphic and logic applications, with key technical challenges and development pathways outlined for their integration into practical intelligent electronic systems.

Abstract Intrinsically stretchable polymer semiconductors (IS‐PSCs) exhibiting simultaneously high charge‐carrier mobility and robust mechanical properties are highly desired yet remain challenging for wearable electronics. Herein, a conjugated non‐aromatic stacking‐inhibiting ( CNASI ) design strategy is proposed by randomly embedding dithienyl‐dimethylcyclopentadiene (2TCp) units into a diketopyrrolopyrrole (DPP)‐based polymer backbone, obtaining a series of near‐linear and fully conjugated terpolymers containing different contents of 2TCp. Specifically, the geminal dimethyl substituents of 2TCp can introduce steric hindrance into the polymer backbone, effectively suppressing tight intermolecular π – π stacking interactions, while enhancing backbone conjugation and planarity owing to the introduction of a non‐aromatic polyene character. Finally, the optimized 2TCp‐15% terpolymer exhibits a high crack onset strain up to 160%, showing an over‐threefold improvement compared to the pristine PDPPT polymer. Moreover, it exhibits an improved initial charge‐carrier mobility ( µ m ax = 1.32 cm 2 V −1 s −1 ), together with excellent mobility retention and cyclic stability under mechanical strain, compared to PDPPT and a fully aromatic terthiophene‐based reference polymer. This study indicates that subtle modulation of interchain π–π interactions and backbone aromaticity via the novel CNASI strategy effectively balances the trade‐off between mechanical stretchability and electrical performance, providing a new approach for designing IS‐PSCs.

Organic solar cells (OSCs) that combine high photovoltaic efficiency with mechanical resilience are critical for wearable devices. However, prevalent acceptors often act as stress concentrators, leading to film embrittlement. A general toughening approach remains elusive. Here, a broadly applicable strategy is introduced using SEEPS, an elastomeric agent with finely-tailored miscibility with the acceptor to toughen OSCs. A toughening parameter η, derived from dynamic mechanical analysis is defined, that quantitatively correlates with elastomer-acceptor miscibility with mechanical enhancement. SEEPS induces pronounced secondary relaxations that dissipate strain energy, yielding an over 11-fold increase in fracture strain. In situ grazing-incidence X-ray scattering reveals that SEEPS preserves molecular packing and suppresses phase separation under strain. The resulting intrinsically stretchable OSCs retain four-fifths of starting efficiency after 500 stretch-release cycles at 40% strain, and sustain its four-fifths efficiency at 52% strain. This work achieves record-breaking efficiency over 16% while preserving exceptional mechanical stretchability, offering insights for high-performance stretchable photovoltaics.

Single-walled carbon nanotube (SWCNT) films are potential materials for thermoelectric generators (TEGs) owing to their flexibility and high thermoelectric performance near 300 K. However, they inherently exhibit low mechanical strength and high thermal conductivity. To address these limitations, SWCNT-based composite films were fabricated by combining SWCNTs with varying amounts of an inorganic-blended acrylic emulsion additive. The resulting SWCNT-based composite films exhibited significantly improved mechanical properties, with breaking strain and tensile strength values approximately thirty and two times higher, respectively, than those of the additive-free SWCNT film. Thermal conductivity decreased from 7.3 W/(m·K) for the additive-free SWCNT film to 2.1 W/(m·K) for the SWCNT-based composite films. Two types of TEGs were fabricated using the composite films: (1) the water-floating TEG, which generated a temperature difference through evaporative cooling; and (2) the standard TEG, which generated a temperature difference when vertically mounted on a heater. The output voltage of the first type of TEGs decreased as the additive amount increased, owing to reduced evaporative cooling. However, the second type of TEGs increased the output voltage by adding the appropriate amount of additive owing to the film's low thermal conductivity. These findings are significantly helpful in using TEGs with appropriate designs and placements.

ABSTRACT Organic electronic devices hold great promise in areas such as flexible wearables, bioelectronics, proactive health. However, achieving high‐resolution, large‐area‐compatible, and low‐cost patterning of functional layers remains a critical bottleneck for their practical application. Photocrosslinker‐based direct microlithography (DML) has emerged as a powerful and versatile approach to address this challenge, owing to its simplicity, broad compatibility, and material generality. This review systematically surveys the recent progress in DML‐enabled patterning for organic electronics, framing its development into three stages: structural integrity preservation, intrinsic material performance retention, and multifaceted performance optimization. Representative photocrosslinker systems applied to semiconducting, dielectric, and other functional layers are examined, and the specific requirements for each layer type are identified. Notably, recent research demonstrates that rationally designed photocrosslinkers not only enable high‐resolution patterning but also simultaneously enhance key properties such as electrical conductivity, mechanical stretchability, and stability. These synergistic improvements expand the functional landscape of organic materials and open new avenues for high‐performance, multifunctional organic devices.

Mechanical Bonds Enable Stretchability–Strength Balance in Graphene-Based Fibers

Abstract Polysaccharide polyelectrolytes with tunable cross‐linked structures and intrinsic conductivity and antibiosis address the energy consumption and high carbon emissions of wearable electronic devices. However, it is a great challenge to fabricate polysaccharide ionohydrogels with high conductivity and low stress loss for new energy generation and storage and other multiple occasion applications. Herein, a novel organogel polyelectrolyte (OST/P(AM‐co‐DMAEA‐Q)/ZA) based on conjoined double cross‐linked networks with high intrinsic conductivity, robust adhesion, and antibacterial properties is successfully prepared using oxidized starch (OST) and poly(ionic liquid) electrolyte (P(AM‐co‐DMAEA‐Q)). The organogel polyelectrolyte exhibits 446% mechanical stretchability, 136 mS m −1 conductivity and 100% antibacterial efficacy against E. coli . A series of self‐powered polyelectrolyte‐based energy and sensing devices are constructed and the assembled triboelectric nanogenerators (TENGs) harvest performance with an open‐circuit voltage of 118 V, while the supercapacitors (SCs) possess a high energy storage capacity of 87.84 mF cm −2 and long‐term durability. Furthermore, the organogel polyelectrolyte demonstrates moisture‐electric generation by utilizing ambient moisture to generate electricity. Additionally, the strain sensors effectively reproducibility detect human motions and serve as temperature sensors with a rapid response rate. This work develops a starch organogel polyelectrolyte for self‐powered energy and sensing applications via the designed dual cross‐linked networks.

Thermoelectric (TE) materials directly convert temperature gradients into electrical potential. However, conventional rigid TE materials are limited by poor mechanical compliance, potential toxicity, and non-recyclability. Here, we present an ionic TE hydrogel that addresses these challenges through high stretchability, full recyclability, and non-toxic composition. The hydrogel can be recycled through an environmentally friendly process that generates no hazardous byproducts. Our material exhibits exceptional mechanical stretchability with 1400% strain capacity, 98% optical transparency, high electrical conductivity (1.9 mS cm-1), and a Seebeck coefficient (−1.05 mV/K). When encapsulated in recyclable polyurethane, the resulting devices enable stable dual-mode sensing through both TE and triboelectric mechanisms, allowing simultaneous temperature and pressure detection without complex signal processing. The devices maintain 96% of their electrical performance even after recycling and self-healing cycles. This innovative hydrogel design strategy aligns with circular economy principles for environment-friendly human-machine interface applications.

Developing stretchable transparent electrodes that simultaneously achieve high conductivity, optical transparency, mechanical stretchability, and environmental stability remains a significant challenge. In this study, a fluorosilane-modified sandpaper template was employed to create a nanosilica-enhanced PDMS composite membrane with a wrinkled surface structure, which enhances the mechanical properties and facilitates the ordered assembly of the conductive materials. The high modulus of the nanosilica preserved the micronano structural integrity after demolding without sacrificing membrane flexibility, while the textured surface and relatively hydrophilic nature enable straightforward surface modification. Through spin-coating and thermal treatment, silver nanowires (AgNWs) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) were sequentially deposited onto the structured membrane, yielding a dense, well-adhered conductive network. The resulting flexible composite electrode retained optical transparency while exhibiting excellent electrical conductivity, enhanced stretchability, and outstanding environmental stability, underscoring its potential for wearable thermal management and strain sensing applications.

ABSTRACT This study presents the fabrication, characterization, and performance evaluation of flexible piezoelectric composites based on polydimethylsiloxane embedded with varying volume fractions (0–25 vol%) of barium titanate nanoparticles. The composites were prepared via a conventional casting method and systematically analyzed to investigate the synergistic enhancement of their mechanical, dielectric, and piezoelectric properties. Structural and morphological analyses confirmed the retention of the crystalline BaTiO3 phase and its uniform dispersion within the PDMS matrix, with some agglomeration observed at higher filler loadings. Mechanical testing revealed that the 20 vol% BaTiO3 composite exhibited optimal tensile strength and flexibility. Dielectric measurements showed significant increase in the dielectric constant with increasing BaTiO3 content, with the 25 vol% composite achieving a 100% enhancement compared to pure PDMS. Theoretical modeling was employed to compare experimental results with established effective medium theories. Under cyclic compression, the composites demonstrated a progressive increase in output voltage, reaching up to ~426 V at 25 vol% BaTiO3, surpassing performance reported in previous studies. Additionally, the incorporation of carbon nanotubes further enhanced dielectric efficiency and mechanical stretchability, although a slight reduction in piezoelectric output was observed. These results underscore the potential of BaTiO3/PDMS nanocomposites, with and without CNTs, for next-generation flexible energy harvesting devices.

ABSTRACT Stretchable electronic devices have increasingly received interest both in the academic and industrial communities because of their potential to break the limitations of traditional rigid devices and further expand the fields of applications, especially in wearable and implantable devices. As the key component of stretchable transistors in stretchable electronics, the design of a suitable stretchable semiconductor is extremely urgent and essential, while the natural flexibility of polymer semiconductor makes it a promising material for stretchable electronics. However, high mechanical stretchability and high mobility simultaneously in one polymer semiconductor is still a challenge, because the two properties are opposite in relationship. In this review, recent strategies to enhance mechanical stretchability in polymer semiconductors while maintaining the mobilities are discussed, including molecular design, physical blending, and near‐amorphous polymer, with emphasis on the control of both thin‐film morphology and polymer‐chain dynamics in the stretchable polymer semiconductor film. Last, challenges and outline future research perspectives of stretchable polymer semiconductors are discussed in conclusions and future prospects.

Coordination bonding is a crucial interaction between heteromaterials that enhances both mechanical toughness and stretchability, with mussels serving as a natural example of thriving in harsh marine environments due to this interaction. However, stretchable electronic materials based on this fundamental interaction have been rarely reported. In this study, a stretchable electrode, called the metal-amine coordination-complex-based electrode (MACE) is introduced, which involves the formation of coordination complexes between a solid metal and an organic layer. MACEs are based on a single Au layer with a thickness of a few tens of nanometers, yet they exhibit excellent stretchability of up to 70% and high durability under strain at 40% for 10 000 cycles without conventional treatments, such as pre-stretching the substrate. Additionally, the direct laser patterning process on the metal film allows for high versatility in forming desirable patterns and adjusting stretchability. Furthermore, by utilizing the mechanical and electrical properties of MACE, a reversible soft actuator with a simple laminated structure is demonstrated. This approach, based on the formation of coordination complexes between heteromaterials, provides insights into fully mechanically stretchable electronics that achieve both softness and toughness simultaneously.

Functionalized Ionogels with Self-healing Performance: Material Design, Chemistry Aspects, Applications, and Future Prospects.

Abstract There has been rapid and continuous development in organic semiconductors for photovoltaics over the past decade, and power conversion efficiencies (PCEs) of nearly 21 % have already been achieved. Organic semiconductors not only offer competitive PCEs but also semitransparency, color tunability, lightweight, solution‐processability, mechanical stretchability, synthetic flexibility, and most importantly, biocompatibility. This combination of properties opens up a range of unconventional applications beyond traditional solar farms, which include building‐integrated installations, smart windows, agrivoltaics, indoor photovoltaics, wearable electronics, and thermoregulatory devices. Hence, initial impressions toward commercial feasibility that are conventionally based on traditional photovoltaic applications could be misleading. This review highlights that organic semiconductors may have already surpassed existing photovoltaic materials in certain types of utilization. Accordingly, the core ideas of emerging unconventional photovoltaic applications, their latest developments, current challenges, and key performance factors beyond PCEs are covered herein. Overall, this mini‐review provides practical perspectives, driving more research attention toward other more up‐to‐date photovoltaic applications with modern technologies and architectural motifs.

Wearable tactile sensors with high stretchability and stable electrical conductivity are crucial for next-generation applications in electronic skin, healthcare monitoring, and human-machine interaction. However, existing designs often encounter challenges related to the mechanical stiffening and signal nonlinearity caused by materials that lack both resilience and the ability of maintaining consistent electrical conductivity under deformation. Herein, we present a polyurethane-poly(3,4-ethylenedioxythiophene) (PU-PEDOT) tactile sensor cross-linked via supramolecular interactions to overcome these limitations. Although PEDOT incorporation provides essential electrical conductivity, its tendency to crystallize diminishes the tensile stretchability and compressive compliance of the PU matrix, undermining phase stability. To overcome this, we introduce a dynamic PolyFlex (PF) network PF-CDPEG, integrating PEGylated sliding cyclodextrins (pseudopolyrotaxanes) (CD-PR), poly(ethylene glycol) methacrylate (PEGMA), and poly(ethylene glycol) diacrylate (PEGDA). The α-CD rings threaded on PEG axles act as supramolecular zipper cross-links, dynamically dissociating and reassociating under strain to dissipate stress and preserve conductive pathways. The optimized PF-CDPEG-Opt sensor, with its engineered porous architecture and supramolecular cross-linking, achieved exceptional mechanical stretchability, sustaining strains up to 1550%, which is critical for next-generation wearable applications. The sensor also demonstrated rapid response and recovery (14 ms/12 ms) and high sensitivity (>300 kPa-1), with a detection limit as low as 0.9-2 Pa. The sensor enables real-time monitoring of physiological signals, including arterial pulse, joint motion, and vocal cord vibration, under diverse conditions. These results demonstrated a scalable strategy for developing flexible and highly sensitive tactile sensors, with broad implications for soft robotics, artificial skin, and biomedical interfaces.

Polymer semiconductors hold great potential for next-generation bionic devices, due to their inherent flexibility and biocompatibility. However, endowing them both robust mechanical properties and significant functionalities remains challenging. Bioinspired microstructures can effectively boost semiconducting properties and functionality, yet the structure engineering strategy in conjugated polymers (CPs) systems is underdeveloped. Here, we fabricate biomimetic hybrid semiconducting films featuring geometry-deformable micromesh and nanofibril substructure, through the Van der Waals force-mediated phase-separation. Poly(butyleneadipate-co-terephthalate) (PBAT), an aggregating polymer with abundant intermolecular interactions, is employed as plastic component to facilitate the formation of hierarchically biomimetic structure. Consequently, this geometry-deformable micromesh and interpenetrating phases significantly enhance mechanical and electrical stretchability of the semiconductors. The dependence of strain dissipation mechanism on structural parameters is identified for micromesh structure optimization. Moreover, the nanofibril substructure significantly improves photosensitivity by 100%. Leveraging the synergistic effect of micromesh and nanofibril, synaptic phototransistors are fabricated, which exhibit superior synaptic plasticity and robust performance under strains up to 125% and 1000 repeated cycles at 50% strain, well imitating the phototransduction and memory functionalities of visual system. This strategy shows great potential for processing ultra-stretchable and high-performance conjugated polymer films aiming at stretchable bioelectronics.