Miniaturized electronics require integrated unit configuration in very limited space, where energy storage per unit area is thus extremely critical. Micro‐supercapacitors (MSCs), mainly established ...on planar substrates, are superior but still suffer from limited areal capacitance. Herein, a novel strategy is introduced to construct high cross‐section MSCs using 3D fabrics as the porous skeleton. Interdigitated poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) is patterned on 3D fabrics to achieve continuous conductive networks, while MnO2 microspheres epitaxially grown on PEDOT:PSS are fully exposed to electrolyte with the support of fabric fibers. The unique architecture can utilize more active sites of thick electrodes and the high conductivity of interpenetrating fiber networks. The resulting fabric‐based MSCs demonstrate ultra‐high areal capacitance of 135.4 mF cm−2, which is 3.5 times that of devices on polyethylene terephthalate substrates and is among the highest values for planar‐based MSCs using the same interdigital geometry. Moreover, the flexible fabrics endow MSCs with extremely high bending stability with 94% capacitance retention even after 3000 cycles. These figures‐of‐merit enable fabric‐based MSCs promising to be used in the next‐generation of wearable electronics.
A 3D fabric structure is employed for the first time as the porous skeleton to construct a high‐section micro‐supercapacitor. This architecture can utilize more active sites of thick electrodes, and the device demonstrates an ultra‐high areal capacitance of 135.4 mF cm−2. Different from the common strategies of using plane substrates, this unique design represents important progress for future wearable/portable electronics.
Printed electronics are an important enabling technology for the development of low‐cost, large‐area, and flexible optoelectronic devices. Transparent conductive films (TCFs) made from ...solution‐processable transparent conductive materials, such as metal nanoparticles/nanowires, carbon nanotubes, graphene, and conductive polymers, can simultaneously exhibit high mechanical flexibility, low cost, and better photoelectric properties compared to the commonly used sputtered indium‐tin‐oxide‐based TCFs, and are thus receiving great attention. This Review summarizes recent advances of large‐area flexible TCFs enabled by several roll‐to‐roll‐compatible printed techniques including inkjet printing, screen printing, offset printing, and gravure printing using the emerging transparent conductive materials. The preparation of TCFs including ink formulation, substrate treatment, patterning, and postprocessing, and their potential applications in solar cells, organic light‐emitting diodes, and touch panels are discussed in detail. The rational combination of a variety of printed techniques with emerging transparent conductive materials is believed to extend the opportunities for the development of printed electronics within the realm of flexible electronics and beyond.
The recent advances of large‐area flexible transparent conductive films (TCFs) enabled by several roll‐to‐roll‐compatible printing techniques including inkjet printing, screen printing, offset printing, and gravure printing using emerging transparent conductive materials are summarized, with the hope of providing timely references for the fabrication of low‐cost/large‐area flexible TCFs and advancing the field of flexible electronics in general.
Flexible and stretchable electronics represent today's cutting‐edge electronic technologies. As the most‐fundamental component of electronics, the thin‐film electrode remains the research frontier ...due to its key role in the successful development of flexible and stretchable electronic devices. Stretchability, however, is generally more challenging to achieve than flexibility. Stretchable electronic devices demand, above all else, that the thin‐film electrodes have the capacity to absorb a large level of strain (>>1%) without obvious changes in their electrical performance. This article reviews the progress in strategies for obtaining highly stretchable thin‐film electrodes. Applications of stretchable thin‐film electrodes fabricated via these strategies are described. Some perspectives and challenges in this field are also put forward.
Progress in strategies for obtaining highly stretchable thin‐film electrodes is reviewed. Such electrodes display tremendous potential in applications for flexible and stretchable electronics, such as stretchable displays, electronic skin, and wearable electronics.
Poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT: PSS) grids have been successfully constructed by roll‐to‐roll compatible screen‐printing techniques and have been used as indium tin ...oxide (ITO)‐free anodes for flexible organic light‐emitting diodes (OLEDs). The grid‐type transparent conductive electrodes (TCEs) can adopt thicker PEDOT: PSS grid lines to ensure the conductivity, while the mesh‐like grid structure can play an important role to maintain high optical transparency. By adjusting grid periods, grid thickness and treatment of organic additives, PEDOT: PSS TCEs with high optical transparency, low sheet resistance, and excellent mechanical flexibility have been achieved. Using the screen‐printed PEDOT: PSS grids as the anodes, ITO‐free OLEDs achieved peak current efficiency of 3.40 cd A−1 at the current density of 10 mA cm−2, which are 1.56 times better than the devices with ITO glass as the anodes. The improved efficiency is attributed to the light extraction effect and improved transparency by the grid structure. The superior optoelectronic performances of OLEDs based on flexible screen‐printed PEDOT: PSS grid anodes suggest their great prospects as ITO‐free anodes for flexible and wearable electronic applications.
Flexible transparent conductive electrodes based on poly(3,4‐ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) grids are achieved by roll‐to‐roll compatible screen printing on polyethylene terephthalate substrates. Flexible organic light‐emitting diodes based on PEDOT:PSS grids as indium tin oxide (ITO)‐free anodes exhibit comparable or even superior performance as compared with those based on ITO glass anodes.
Stretchable self‐healing supercapacitors (SCs) can operate under extreme deformation and restore their initial properties after damage with considerably improved durability and reliability, expanding ...their opportunities in numerous applications, including smart wearable electronics, bioinspired devices, human–machine interactions, etc. It is challenging, however, to achieve mechanical stretchability and self‐healability in energy storage technologies, wherein the key issue lies in the exploitation of ideal electrode and electrolyte materials with exceptional mechanical stretchability and self‐healing ability besides conductivity. Conductive hydrogels (CHs) possess unique hierarchical porous structure, high electrical/ionic conductivity, broadly tunable physical and chemical properties through molecular design and structure regulation, holding tremendous promise for stretchable self‐healing SCs. Hence, this review is innovatively constructed with a focus on stretchable and self‐healing CH based electrodes and electrolytes for SCs. First, the common synthetic approaches of CHs are introduced; then the stretching and self‐healing strategies involved in CHs are systematically elaborated; followed by an explanation of the conductive mechanism of CHs; then focusing on CH‐based electrodes and electrolytes for stretchable self‐healing SCs; subsequently, application of stretchable and self‐healing SCs in wearable electronics are discussed; finally, a conclusion is drawn along with views on the challenges and future research directions regarding the field of CHs for SCs.
Conductive hydrogels (CHs) are a new class of soft functional materials that have recently found application in flexible energy storage devices such as batteries and supercapacitors (SCs). Herein, the promise of CHs in this emerging field is demonstrated through summarizing their roles as ideal electrode and electrolyte materials for stretchable and self‐healing SCs.
Ultra‐flexible stretchable organic light‐emitting diodes (OLEDs) are emerging as a basic component of flexible electronics and human‐machine interfaces. However, the brightness and efficiency of ...stretchable OLEDs remain still far inferior to their rigid counterparts, owing to the scarcity of satisfactory stretchable electroluminescent materials. Herein, we explore a general concept based on the self‐confinement effect to dramatically improve the stretchability of elastomers, without affecting electroluminescent properties. The balanced rigid/flexible chain dynamics under self‐confinement significantly reduces the modulus of the elastomers, resulting in the maximum strain reaching 806 %. Ultra‐flexible stretchable OLEDs have been constructed based on the resulting ISEEs, achieving unprecedented high‐performance non‐blended stretchable OLEDs. The results suggest an effective molecular design strategy for highly deformable stretchable displays and flexible electronics.
Achieving high‐performance electroluminescence under large deformation remains a grand challenge. In this contribution, a general concept based on the self‐confinement effect has been proposed for the design and synthesis of non‐blended intrinsically stretchable electroluminescent elastomers (ISEEs). High‐performance non‐blended stretchable OLEDs have been constructed based on the resulting ISEEs.
An extremely simple in situ self‐transformation methodology is developed to introduce pseudocapacitance into the MOF system resulting in a largely boosted electrochemical performance: a three‐fold ...increase in capacitance as well as improved rate capacity. An all‐solid‐state hybrid flexible supercapacitor is fabricated based on the obtained MnOx–MHCF composite and activated carbon with an areal capacitance of 175 mF cm−2 at 0.5 mA cm−2.
Sepsis-associated encephalopathy (SAE) is commonly complicated by septic conditions, and is responsible for increased mortality and poor outcomes in septic patients. Uncontrolled neuroinflammation ...and ischemic injury are major contributors to brain dysfunction, which arises from intractable immune malfunction and the collapse of neuroendocrine immune networks, such as the cholinergic anti-inflammatory pathway, hypothalamic-pituitary-adrenal axis, and sympathetic nervous system. Dysfunction in these neuromodulatory mechanisms compromised by SAE jeopardizes systemic immune responses, including those of neutrophils, macrophages/monocytes, dendritic cells, and T lymphocytes, which ultimately results in a vicious cycle between brain injury and a progressively aberrant immune response. Deep insight into the crosstalk between SAE and peripheral immunity is of great importance in extending the knowledge of the pathogenesis and development of sepsis-induced immunosuppression, as well as in exploring its effective remedies.
Organic light‐emitting transistors (OLETs), as novel and attractive kinds of organic electronic devices, have gained extensive attention from both academia and industry. The unique device ...architectures can simultaneously combine the electrical switching functionality of organic field‐effect transistors and the light generation capability of organic light‐emitting diodes in a single device, thereby holding great promise for reducing the complicated processes of next‐generation pixel circuitry. This review involves the design, fabrication, and applications of OLETs with a comprehensive coverage of this field with the aim to give a deep insight into the intrinsic mechanisms of devices. Challenges and future prospects of OLETs are also discussed.
Organic light‐emitting transistors (OLETs) represent a novel class of organic optoelectronic devices that combine the current modulating function of a transistor with light emission. Unipolar OLETs, ambipolar OLETs, and new device structures, most of which intend to elaborate their working principles and the construction of high‐quality optoelectronic devices, are spotlighted in terms of the representative paradigms.
How organ-specific metastatic traits arise in primary tumors remains unknown. Here, we show a role of the breast tumor stroma in selecting cancer cells that are primed for metastasis in bone. ...Cancer-associated fibroblasts (CAFs) in triple-negative (TN) breast tumors skew heterogeneous cancer cell populations toward a predominance of clones that thrive on the CAF-derived factors CXCL12 and IGF1. Limiting concentrations of these factors select for cancer cells with high Src activity, a known clinical predictor of bone relapse and an enhancer of PI3K-Akt pathway activation by CXCL12 and IGF1. Carcinoma clones selected in this manner are primed for metastasis in the CXCL12-rich microenvironment of the bone marrow. The evidence suggests that stromal signals resembling those of a distant organ select for cancer cells that are primed for metastasis in that organ, thus illuminating the evolution of metastatic traits in a primary tumor and its distant metastases.
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•The primary tumor stroma can determine organ-specific metastatic tropism•CAFs in breast tumors select for bone metastatic cells•CAF-rich tumors mimic the CXCL12-rich microenvironment of the bone marrow•CAF-derived CXCL12 and IGF1 select for high Src activity, a bone metastatic trait
Noncancerous mesenchymal cells in certain breast tumors can influence the direction of metastasis. The cells secrete growth factors that also abound in bone marrow, favoring accumulation of cancer cells that thrive on these factors both in the primary tumor microenvironment and in the bone marrow.
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