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1.
Nature ; 614(7948): 456-462, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36792740

RESUMO

Stretchable hybrid devices have enabled high-fidelity implantable1-3 and on-skin4-6 monitoring of physiological signals. These devices typically contain soft modules that match the mechanical requirements in humans7,8 and soft robots9,10, rigid modules containing Si-based microelectronics11,12 and protective encapsulation modules13,14. To make such a system mechanically compliant, the interconnects between the modules need to tolerate stress concentration that may limit their stretching and ultimately cause debonding failure15-17. Here, we report a universal interface that can reliably connect soft, rigid and encapsulation modules together to form robust and highly stretchable devices in a plug-and-play manner. The interface, consisting of interpenetrating polymer and metal nanostructures, connects modules by simply pressing without using pastes. Its formation is depicted by a biphasic network growth model. Soft-soft modules joined by this interface achieved 600% and 180% mechanical and electrical stretchability, respectively. Soft and rigid modules can also be electrically connected using the above interface. Encapsulation on soft modules with this interface is strongly adhesive with an interfacial toughness of 0.24 N mm-1. As a proof of concept, we use this interface to assemble stretchable devices for in vivo neuromodulation and on-skin electromyography, with high signal quality and mechanical resistance. We expect such a plug-and-play interface to simplify and accelerate the development of on-skin and implantable stretchable devices.


Assuntos
Eletromiografia , Eletrônica Médica , Nanoestruturas , Maleabilidade , Polímeros , Próteses e Implantes , Dispositivos Eletrônicos Vestíveis , Humanos , Nanoestruturas/química , Polímeros/química , Pele , Monitorização Fisiológica , Eletrônica Médica/instrumentação , Eletrônica Médica/métodos , Eletromiografia/instrumentação
2.
Nature ; 624(7991): 295-302, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38092907

RESUMO

Connecting different electronic devices is usually straightforward because they have paired, standardized interfaces, in which the shapes and sizes match each other perfectly. Tissue-electronics interfaces, however, cannot be standardized, because tissues are soft1-3 and have arbitrary shapes and sizes4-6. Shape-adaptive wrapping and covering around irregularly sized and shaped objects have been achieved using heat-shrink films because they can contract largely and rapidly when heated7. However, these materials are unsuitable for biological applications because they are usually much harder than tissues and contract at temperatures higher than 90 °C (refs. 8,9). Therefore, it is challenging to prepare stimuli-responsive films with large and rapid contractions for which the stimuli and mechanical properties are compatible with vulnerable tissues and electronic integration processes. Here, inspired by spider silk10-12, we designed water-responsive supercontractile polymer films composed of poly(ethylene oxide) and poly(ethylene glycol)-α-cyclodextrin inclusion complex, which are initially dry, flexible and stable under ambient conditions, contract by more than 50% of their original length within seconds (about 30% per second) after wetting and become soft (about 100 kPa) and stretchable (around 600%) hydrogel thin films thereafter. This supercontraction is attributed to the aligned microporous hierarchical structures of the films, which also facilitate electronic integration. We used this film to fabricate shape-adaptive electrode arrays that simplify the implantation procedure through supercontraction and conformally wrap around nerves, muscles and hearts of different sizes when wetted for in vivo nerve stimulation and electrophysiological signal recording. This study demonstrates that this water-responsive material can play an important part in shaping the next-generation tissue-electronics interfaces as well as broadening the biomedical application of shape-adaptive materials.


Assuntos
Eletrofisiologia , Polímeros , Água , Animais , alfa-Ciclodextrinas/química , Eletrodos , Eletrofisiologia/instrumentação , Eletrofisiologia/métodos , Eletrofisiologia/tendências , Coração , Músculos , Polietilenoglicóis/química , Polímeros/química , Seda/química , Aranhas , Água/química , Hidrogéis/química , Eletrônica/instrumentação , Eletrônica/métodos , Eletrônica/tendências
3.
Small ; 18(19): e2200533, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35388964

RESUMO

The demand for stretchable electronics with a broader working range is increasing for wide application in wearable sensors and e-skin. However, stretchable conductors based on soft elastomers always exhibit low working range due to the inhomogeneous breakage of the conductive network when stretched. Here, a highly stretchable and self-healable conductor is reported by adopting polyrotaxane and disulfide bonds into the binding layer. The binding layer (PR-SS) builds the bridge between polymer substrates (PU-SS) and silver nanowires (AgNWs). The incorporation of sliding molecules endows the stretchable conductor with a long sensing range (190%) due to the energy dissipation derived from the sliding nature of polyrotaxanes, which is two times higher than the working range (93%) of conductors based on AP-SS without polyrotaxanes. Furthermore, the mechanism of sliding effect for the polyrotaxanes in the elastomers is investigated by SEM for morphological change of AgNWs, in situ small-angle x-ray scattering, as well as stress relaxation experiments. Finally, human-body-related sensing tests and a self-correction system in fitness are designed and demonstrated.


Assuntos
Ciclodextrinas , Rotaxanos , Elastômeros/química , Condutividade Elétrica , Humanos , Polímeros/química
4.
Acc Chem Res ; 52(1): 82-90, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30586278

RESUMO

Stretchable strain sensors, which convert mechanical stimuli into electrical signals, largely fuel the growth of wearable bioelectronics due to the ubiquitous, health-related strain in biological systems. In contrast to rigid conventional strain sensors, stretchable strain sensors present advantages of conformality and stretchability, solving the mechanical mismatch between electronics and the human body. However, the great challenge of stretchable strain sensors lies in achieving high sensitivity, which is required for both signal fidelity and cost considerations. Recent advances to solve this sensitivity challenge have focused on material optimization, in search of the optimum combination of conductive active materials and elastomer substrates among a myriad of artificial or natural materials. However, high sensitivity with a gauge factor larger than 50 remains a grand challenge, especially within large-strain regions. Here we present heterogeneous strain distribution of elastomer substrates as a powerful strategy to significantly enhance the sensitivity of stretchable strain sensors. The theoretical foundation of this strategy is mathematically proven on the basis of Ohm's law in electrics and mechanics of materials. First, the extent of the sensitivity enhancement is proved to be determined by the local strain in resistance-testing segments of heterogeneous strain sensors. Next, the local strain is proved to be quantitatively decided by material properties such as section area and Young's modulus. Thus, the necessary and sufficient condition to achieve high sensitivity in heterogeneous strain sensors is that the Young's modulus reciprocal or section area reciprocal in the resistance-testing segment is larger than the mean value. This provides a theoretical design guideline to achieve high sensitivity via heterogeneous strain distribution. On the basis of this guideline, we systematically summarize concrete instances of heterogeneity-induced sensitivity improvement in stretchable strain sensors, in sequence of increasing dimensionality. A typical example of a one-dimensional heterogeneous strain sensor is a structured fiber with microbeads, where the varied section area along the fiber axis results in heterogeneous strain and sensitivity improvement. Two-dimensional heterogeneous sensors in the form of thin films contain thickness gradient sensors and auxetic mechanical metamaterial sensors. The former exhibit heterogeneous section area via the self-pinning method, while the latter show heterogeneity in both the strain direction and amplitude, leading to a 24-fold improvement in sensitivity. Three-dimensional strain sensors include rationally structured sensors for out-of-plane force detection and asymmetric active materials in electronic whiskers. The resultant enhanced sensitivity in these heterogeneous strain sensors is beneficial for applications such as continuous health monitoring, biomedical diagnostics, and replacement prosthetics, taking advantage of augmented detection accuracy and declined device cost. Finally, we discuss possible future work in exploiting heterogeneous strain distributions, involving extended methodology to achieve heterogeneity, employing suppressed strain for stretchable electrodes, cyclic durability for long-term applications, and multifunctional system-level integration. We believe that this strategy of using heterogeneous strain distribution to enhance sensitivity can strongly promote the development of stretchable strain sensors for both practical and theoretical requirements.


Assuntos
Técnicas Biossensoriais/métodos , Elastômeros/química , Dispositivos Eletrônicos Vestíveis , Técnicas Biossensoriais/instrumentação , Módulo de Elasticidade , Humanos , Modelos Biológicos
5.
Opt Lett ; 43(12): 2764-2767, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29905683

RESUMO

Microwave absorber with broadband absorption and thin thickness is one of the main research interests in this field. A flexible ultrathin and broadband microwave absorber comprising multiwall carbon nanotubes, spherical carbonyl iron, and silicone rubber is fabricated in a newly proposed pyramidal spatial periodic structure (SPS). The SPS with equivalent thickness of 3.73 mm covers the -10 dB and -15 dB absorption bandwidth in the frequency range 2-40 GHz and 10-40 GHz, respectively. The excellent absorption performance is achieved by concentration and dissipation of the electromagnetic field inside different parts of the magnetic-dielectric lossy protrusions in different frequency ranges.

6.
Adv Sci (Weinh) ; 11(4): e2306119, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38036422

RESUMO

Tunable radar stealth structures are critical components for future military equipment because of their potential to further enhance the design space and performance. Some previous investigations have utilized simple origami structures as the basic adjusting components but failed to achieve the desired broadband microwave absorbing characteristic. Herein, a novel double-broadband switchable microwave absorbing grid structure has been developed with the actuators of inflatable Kresling origami structures. Geometric constraints are derived to endow a bistable feature with this origami configuration, and the stable states are switched by adjusting the internal pressure. An ultra-broadband microwave absorbing structure is proposed with a couple of complementary microwave stealth bands, and optimized by a particle swarm optimization algorithm. The superior electromagnetic performance results from the mode switch activating different absorbing components at corresponding frequencies. A digital adjusting strategy is applied, which effectively achieves a continuously adjusting effect. Further investigations show that the proposed structure possesses superior robustness. In addition, minimal interactions are found between adjacent grid units, and the electromagnetic performance is mainly related to the duty ratio of the units in different states. They have enhanced the microwave absorbing performance of grid structures through a tunable design, a provided a feasible paradigm for other tunable absorbers.

7.
Adv Mater ; 36(25): e2400950, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38581284

RESUMO

Mixed conducting materials with both ionic and electronic conductivities have gained prominence in emerging applications. However, exploring material with on-demand ionic and electronic conductivities remains challenging, primarily due to the lack of correlating macroscopic conductivity with atom-scale structure. Here, the correlation of proton-electron conductivity and atom-scale structure in graphdiyne is explored. Precisely adjusting the conjugated diynes and oxygenic functional groups in graphdiyne yields a tunable proton-electron conductivity on the order of 103. In addition, a wet-chemistry lithography technique for uniform preparation of graphdiyne on flexible substrates is provided. Utilizing the proton-electron conductivity and mechanical tolerance of graphdiyne, bimodal flexible devices serving as capacitive switches and resistive sensors are created. As a proof-of-concept, a breath-machine interface for sentence-based communication and self-nursing tasks with an accuracy of 98% is designed. This work represents an important step toward understanding the atom-scale structure-conductivity relationship and extending the applications of mixed conducting materials to assistive technology.

8.
Natl Sci Rev ; 11(6): nwae158, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38881574

RESUMO

Fiber electronics with flexible and weavable features can be easily integrated into textiles for wearable applications. However, due to small sizes and curved surfaces of fiber materials, it remains challenging to load robust active layers, thus hindering production of high-sensitivity fiber strain sensors. Herein, functional sensing materials are firmly anchored on the fiber surface in-situ through a hydrolytic condensation process. The anchoring sensing layer with robust interfacial adhesion is ultra-mechanically sensitive, which significantly improves the sensitivity of strain sensors due to the easy generation of microcracks during stretching. The resulting stretchable fiber sensors simultaneously possess an ultra-low strain detection limit of 0.05%, a high stretchability of 100%, and a high gauge factor of 433.6, giving 254-folds enhancement in sensitivity. Additionally, these fiber sensors are soft and lightweight, enabling them to be attached onto skin or woven into clothes for recording physiological signals, e.g. pulse wave velocity has been effectively obtained by them. As a demonstration, a fiber sensor-based wearable smart healthcare system is designed to monitor and transmit health status for timely intervention. This work presents an effective strategy for developing high-performance fiber strain sensors as well as other stretchable electronic devices.

9.
Int J Med Sci ; 10(12): 1615-24, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24151433

RESUMO

BACKGROUND: The activation of the renin-angiotensin system (RAS) and lipid disorders are major risk factors in progressive chronic kidney disease. This study aimed to investigate the potential synergistic mechanisms of RAS activation and lipid disorders that contribute to glomerulosclerosis. MATERIALS AND METHODS: Human renal mesangial cells (HMCs) were treated with 10(-7) mol/L angiotensin II (Ang II) or with 30 µg/ml cholesterol and 1 µg/ml 25-hydroxycholesterol (lipid loading) for 24 hours. Lipid accumulation in the cells was evaluated by Oil Red O staining and intracellular cholesterol quantitative assays. The gene and protein expression of molecules in the low-density lipoprotein receptor (LDLr) pathway, the RAS family, and the extracellular matrix were examined by real-time polymerase chain reaction and Western blotting. The translocation of sterol regulatory element-binding protein (SREBP) cleavage activating protein (SCAP), which escorts SREBP-2 from the endoplasmic reticulum (ER) to the Golgi, was examined by immunofluorescent staining. RESULTS: Ang II increased lipid droplet accumulation in HMCs. Further analysis revealed that Ang II increased the mRNA and protein expression of LDLr, SCAP, and SREBP-2. This increase was correlated with an enhanced translocation of the SCAP/SREBP-2 complex from the ER to the Golgi in HMCs that was induced by Ang II, thereby activating LDLr gene transcription. Interestingly, lipid loading increased the mRNA and protein expression of angiotensinogen, Ang II, renin, angiotensin-converting enzyme, angiotensin II type 1 receptor, and type 2 receptor in HMCs with increased mRNA and protein expression of collagen I, α-smooth muscle actin, and fibronectin. CONCLUSIONS: This study demonstrates that the interaction of RAS activation and lipid disorders accelerates the progression of glomerulosclerosis.


Assuntos
Angiotensina II/administração & dosagem , Nefropatias Diabéticas/genética , Metabolismo dos Lipídeos/efeitos dos fármacos , Proteínas ras/genética , Angiotensina II/metabolismo , Colesterol/administração & dosagem , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Progressão da Doença , Retículo Endoplasmático/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Hidroxicolesteróis/administração & dosagem , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Proteínas de Membrana/biossíntese , Células Mesangiais/efeitos dos fármacos , Células Mesangiais/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Receptores de Lipoproteínas/biossíntese , Receptores de Lipoproteínas/metabolismo , Sistema Renina-Angiotensina/genética , Proteína de Ligação a Elemento Regulador de Esterol 2/biossíntese , Proteínas de Ligação a Elemento Regulador de Esterol/biossíntese , Proteínas ras/metabolismo
10.
Lipids Health Dis ; 12: 49, 2013 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-23570453

RESUMO

BACKGROUND: Dyslipidemia and activation of renin-angiotensin system (RAS) contribute to the progression of chronic kidney disease (CKD). This study investigated possible synergistic effects of intrarenal RAS activation with hyperlipidemia in renal injuries. METHODS: Apolipoprotein knockout mice were fed with normal chow diet (control) or high fat diet (HF group) for eight weeks. Human proximal tubular epithelial cell line (HK-2) was treated without (control) or with cholesterol (30 µg/ml) plus 25-hydroxycholesterol (1 µg/ml) (lipid group) for 24 hours. The plasma lipid profile and RAS components were determined by clinical biochemistry assay and radiommunoassay, respectively. Collagen deposition in kidneys was evaluated by Masson-staining. The gene and protein expressions of molecules involved in RAS components and biomarkers of epithelial mesenchymal transition (EMT) were examined by real-time PCR, immunochemical staining, and Western blot. RESULTS: The mice fed with high-fat diet showed significant hyperlipidemia with collagen deposition in renal tubular interstitium compared to controls. The plasma levels of renin, angiotensin I, and angiotensin II were no difference in two groups. However, the kidneys of HF group showed up-regulated RAS components, which were positively associated with increased plasma levels of triglyceride, total cholesterol, and LDL. These effects were further confirmed by in vitro studies. Lipid loading induced HK-2 cells underwent EMT, which was closely associated with the increased expressions of intracellular RAS components. CONCLUSIONS: Local RAS activation was involved in hyperlipidemia-mediated renal injuries, suggesting that there are synergistic effects resulting from RAS activation with hyperlipidemia that accelerates the progression of CKD.


Assuntos
Apolipoproteínas E/genética , Dislipidemias/complicações , Túbulos Renais Proximais/fisiopatologia , Sistema Renina-Angiotensina/fisiologia , Animais , Apolipoproteínas E/metabolismo , Caderinas/metabolismo , Linhagem Celular/efeitos dos fármacos , Colesterol/metabolismo , Colesterol/farmacologia , Dieta Hiperlipídica/efeitos adversos , Dislipidemias/fisiopatologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Transição Epitelial-Mesenquimal/genética , Humanos , Hidroxicolesteróis/farmacologia , Túbulos Renais Proximais/citologia , Túbulos Renais Proximais/efeitos dos fármacos , Masculino , Camundongos Knockout , Sistema Renina-Angiotensina/efeitos dos fármacos
11.
Adv Mater ; 35(1): e2207969, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36281792

RESUMO

Ambient-pressure-dried (APD) preparation of transition metal carbide/nitrides (MXene) aerogels is highly desirable yet remains highly challenging. Here, ultrathin, high-strength-to-weight-ratio, renewable cellulose nanofibers (CNFs) are efficiently utilized to assist in the APD preparation of ultralight yet robust, highly conductive, large-area MXene-based aerogels via a facile, energy-efficient, eco-friendly, and scalable freezing-exchanging-drying approach. The strong interactions of large-aspect-ratio CNF and MXene as well as the biomimetic nacre-like microstructure induce high mechanical strength and stability to avoid the structure collapse of aerogels in the APD process. Abundant functional groups of CNFs facilitate the chemical crosslinking of MXene-based aerogels, significantly improving the hydrophobicity, water resistance, and even oxidation stability. The ultrathin, 1D nature of the CNF renders the minimal MXenes' interlayered gaps and numerous heterogeneous interfaces, yielding the excellent conductivity and electromagnetic interference (EMI) shielding performance of aerogels. The synergies of the MXene, CNF, and abundant pores efficiently improve the EMI shielding performance, photothermal conversion, and absorption of viscous crude oil. This work shows great promises of the APD, multifunctional MXene-based aerogels in electromagnetic protection or compatibility, thermal therapy, and oil-water separation applications.

12.
ACS Appl Mater Interfaces ; 15(6): 7663-7672, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36734973

RESUMO

The cuff electrode can be wrapped in the columnar or tubular biological tissue for physiological signal detection or stimulation regulation. The reliable and non-excessive interfaces between the electrode and complex tissue are critical. Here, we propose a self-closing stretchable cuff electrode, which is able to self-close onto the bundles of tissues after dropping water. The curliness is realized by the mechanical stress mismatch between different layers of the elastic substrate. The material of the substrate can be selected to match the modulus of the target tissue to achieve minimal constraint on the tissue. Moreover, the self-closing structure keeps the cuff electrode free from any extra mechanical locking structure. For in vivo testing, both sciatic nerve stimulation to drive muscles and electromyographic signal monitoring around a rat's extensor digitorum longus for 1 month prove that our proposed electrode conforms well to the curved surface of biological tissue.


Assuntos
Músculo Esquelético , Nervo Isquiático , Ratos , Animais , Estimulação Elétrica , Nervo Isquiático/fisiologia , Eletrodos , Músculo Esquelético/fisiologia , Eletrodos Implantados
13.
ACS Sens ; 8(7): 2691-2701, 2023 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-37262351

RESUMO

Contact lens sensors provide a noninvasive approach for intraocular pressure (IOP) monitoring in patients with glaucoma. Accurate measurement of this imperceptible pressure variation requires highly sensitive sensors in the absence of simultaneously amplifying IOP signal and blinking-induced noise. However, current noise-reduction methods rely on external filter circuits, which thicken contact lenses and reduce signal quality. Here, we introduce a contact lens strain sensor with an anti-jamming ability by utilizing a self-lubricating layer to reduce the coefficient of friction (COF) to remove the interference from the tangential force. The sensor achieves exceptionally high sensitivity due to the strain concentration layout and the confined occurrence of sympatric microcracks. The animal tests prove our lens can accurately detect IOP safely and reliably.


Assuntos
Lentes de Contato , Glaucoma , Animais , Pressão Intraocular , Tonometria Ocular/métodos , Glaucoma/diagnóstico
14.
ACS Nano ; 17(13): 12510-12518, 2023 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-37350557

RESUMO

Metal-organic frameworks (MOFs) manifest enormous potential in promoting electromagnetic wave (EMW) absorption thanks to the tailored components, topological structure, and high porosity. Herein, rodlike conductive MOFs (cMOFs) composed of adjustable metal ions of Zn, Cu, Co, or Ni and ligands of hexahydroxytriphenylene (HHTP) are prepared to attain tunable dielectric properties for a tailored EMW absorption. Specifically, the influences of the cMOFs' composition, charge transport characteristic, topological crystalline structure, and anisotropy microstructure on dielectric and EMW absorption performance are ascertained, advancing the understanding of EMW attenuation mechanisms of MOFs. The boosted conductive and polarization losses derived from the conjugation effects and terminal groups, as well as shape anisotropy, lead to a prominent EMW absorption of the cMOFs. The Cu-HHTP confers a minimum reflection loss (RLmin) of -63.55 dB at the thickness of 2.9 mm and a maximum effective absorption bandwidth of 5.2 GHz. Moreover, Zn-HHTP showcases the absorption superiority in the S-band (2-4 GHz) with an RLmin of -62.8 dB at a thickness of 1.9 mm. This work not only hoists the mechanistic understanding of the structure-function relationships for the cMOFs but also offers guidelines for preparing functional MOF materials.

15.
Adv Mater ; 34(1): e2102560, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34632642

RESUMO

Phase transitions are universal in solid-state matters, as well as in periodic electromagnetic metasurfaces-the photonic analogues of crystals. Although such transitions dictate the properties of active metasurfaces, universal ways to describe the structure transition of periodic metasurfaces have not yet been established. Here, the authors report the strain-enabled phase transition (or lattice deformation) of stretchable metasurfaces with the crystallographic description. They analytically and experimentally demonstrate the phase transition of plasmonic lattices between two arbitrary 2D Bravais lattices under certain strain configurations. The strain-induced symmetry lowering of the structures gives rise to optical anisotropy upon polarization, namely, linearly and circularly polarized dichroism. They further demonstrate the potential of phase transition in information decoding with applied strain. Interpreting the phase transition of metasurfaces from a standpoint of symmetry would accelerate the discovery of emergent properties, and provide a generalizable approach to designing active metasurfaces.

16.
Adv Mater ; 34(30): e2202877, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35638695

RESUMO

Flexible electrodes that are multilayer, multimaterial, and conformal are pivotal for multifunctional wearable electronics. Traditional electronic circuits manufacturing requires substrate-supported transfer printing, which limits their multilayer integrity and device conformability on arbitrary surfaces. Herein, a "shrinkage-assisted patterning by evaporation" (SHAPE) method is reported, by employing evaporation-induced interfacial strain mismatch, to fabricate auto-detachable, freestanding, and patternable electrodes. The SHAPE method utilizes vacuum-filtration of polyaniline/bacterial cellulose (PANI/BC) ink through a masked filtration membrane to print high-resolution, patterned, and multilayer electrodes. The strong interlayer hydrogen bonding ensures robust multilayer integrity, while the controllable evaporative shrinking property of PANI/BC induces mismatch between the strains of the electrode and filtration membrane at the interface and thus autodetachment of electrodes. Notably, a 500-layer substrateless micro-supercapacitor fabricated using the SHAPE method exhibits an energy density of 350 mWh cm-2 at a power density of 40 mW cm-2 , 100 times higher than reported substrate-confined counterparts. Moreover, a digital circuit fabricated using the SHAPE method functions stably on a deformed glove, highlighting the broad wearable applications of the SHAPE method.

17.
Adv Mater ; 34(7): e2101339, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34978104

RESUMO

Stretchable electronics incorporating critical sensing, data transmission, display and powering functionalities, is crucial to emerging wearable healthcare applications. To date, methods to achieve stretchability of individual functional devices have been extensively investigated. However, integration strategies of these stretchable devices to achieve all-stretchable systems are still under exploration, in which the reliable stretchable interconnection is a key element. Here, solderless stretchable interconnections based on mechanically interlocking microbridges are developed to realize the assembly of individual stretchable devices onto soft patternable circuits toward multifunctional all-stretchable platforms. This stretchable interconnection can effectively bridge interlayer conductivity with tight adhesion through both conductive microbridges and selectively distributed adhesive polymer. Consequently, enhanced stretchability up to a strain of 35% (R/R0  ≤ 5) is shown, compared with conventional solder-assisted connections which lose electrical conduction at a strain of less than 5% (R/R0  ≈ 30). As a proof of concept, a self-powered all-stretchable data-acquisition platform is fabricated by surface mounting a stretchable strain sensor and a supercapacitor onto a soft circuit through solderless interconnections. This solderless interconnecting strategy for surface-mountable devices can be utilized as a valuable technology for the integration of stretchable devices to achieve all-soft multifunctional systems.

18.
Nat Commun ; 13(1): 7294, 2022 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-36435805

RESUMO

Three-dimensional (3D) architectures have qualitatively expanded the functions of materials and flexible electronics. However, current fabrication techniques for devices constrain their substrates to 2D geometries and current post-shape transformation strategies are limited to heterogenous or responsive materials and are not amenable to free-standing inert plastic films such as polyethylene terephthalate (PET) and polyimide (PI), which are vital substrates for flexible electronics. Here, we realize the shape morphing of homogeneous plastic films for various free-standing 3D frameworks from their 2D precursors by introducing a general strategy based on programming the plastic strain in films under peeling. By modulating the peeling parameters, previously inaccessible free-standing 3D geometries ranging from millimeter to micrometer were predicted theoretically and obtained experimentally. This strategy is applicable to most materials capable of plastic deformation, including polymers, metals, and composite materials, and can even enable 4D transformation with responsive plastic films. Enhanced performance of 3D circuits and piezoelectric systems demonstrates the enormous potential of peeling-induced shape morphing for 3D devices.

19.
Adv Mater ; 34(25): e2104078, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34423476

RESUMO

Simple and rapid Young's modulus measurements of soft materials adaptable to various scenarios are of general significance, and they require miniaturized measurement platforms with easy operation. Despite the advances made in portable and wearable approaches, acquiring and analyzing multiple or complicated signals necessitate tethered bulky components and careful preparation. Here, a new methodology based on a self-locked stretchable strain sensor to haptically quantify Young's modulus of soft materials (kPa-MPa) rapidly is reported. The method demonstrates a fingertip measurement platform, which endows a prosthetic finger with human-comparable haptic behaviors and skills on elasticity sensing without activity constraints. A universal strategy is offered toward ultraconvenient and high-efficient Young's modulus measurements with wide adaptability to various fields for unprecedented applications.


Assuntos
Técnicas de Imagem por Elasticidade , Módulo de Elasticidade , Elasticidade , Técnicas de Imagem por Elasticidade/métodos , Humanos
20.
Adv Mater ; 34(4): e2106212, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34738253

RESUMO

Memristors constitute a promising functional component for information storage and in-memory computing in flexible and stretchable electronics including wearable devices, prosthetics, and soft robotics. Despite tremendous efforts made to adapt conventional rigid memristors to flexible and stretchable scenarios, stretchable and mechanical-damage-endurable memristors, which are critical for maintaining reliable functions under unexpected mechanical attack, have never been achieved. Here, the development of stretchable memristors with mechanical damage endurance based on a discrete structure design is reported. The memristors possess large stretchability (40%) and excellent deformability (half-fold), and retain stable performances under dynamic stretching and releasing. It is shown that the memristors maintain reliable functions and preserve information after extreme mechanical damage, including puncture (up to 100 times) and serious tearing situations (fully diagonally cut). The structural strategy offers new opportunities for next-generation stretchable memristors with mechanical damage endurance, which is vital to achieve reliable functions for flexible and stretchable electronics even in extreme and highly dynamic environments.

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