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1.
Microsyst Nanoeng ; 7: 85, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34745644

RESUMO

Skin-integrated electronics, also known as electronic skin (e-skin), are rapidly developing and are gradually being adopted in biomedical fields as well as in our daily lives. E-skin capable of providing sensitive and high-resolution tactile sensations and haptic feedback to the human body would open a new e-skin paradigm for closed-loop human-machine interfaces. Here, we report a class of materials and mechanical designs for the miniaturization of mechanical actuators and strategies for their integration into thin, soft e-skin for haptic interfaces. The mechanical actuators exhibit small dimensions of 5 mm diameter and 1.45 mm thickness and work in an electromagnetically driven vibrotactile mode with resonance frequency overlapping the most sensitive frequency of human skin. Nine mini actuators can be integrated simultaneously in a small area of 2 cm × 2 cm to form a 3 × 3 haptic feedback array, which is small and compact enough to mount on a thumb tip. Furthermore, the thin, soft haptic interface exhibits good mechanical properties that work properly during stretching, bending, and twisting and therefore can conformally fit onto various parts of the human body to afford programmable tactile enhancement and Braille recognition with an accuracy rate over 85%.

2.
Artigo em Inglês | MEDLINE | ID: mdl-34757546

RESUMO

Stroke is the third leading cause of death in the United States and the leading cause of adult disability. Despite enormous research efforts including many clinical trials, tissue plasminogen activator (tPA) remains the only FDA-approved treatment for acute ischemic stroke. Unfortunately, only 1-3% of stroke patients in the US receive this therapy because of the narrow time window and severe side effects for using tPA. The most deadly and damaging side effect is the risk of intracranial bleeding or hemorrhage. For that reason, the dose of tPA and its overall administration are under tight control, which may compromise the effect of thrombolysis. Studies have been focused on improving the effectiveness of tPA for higher rate of reperfusion, and the safety for less adverse bleeding episode. We studied how metal ions (zinc & iron) affect tPA-induced thrombolysis in vitro and in vivo, and proposed a method to improve the rate of thrombolysis. The amount of hemoglobin in the blood clot lysis was measured by a spectrophotometer. The tPA-induced thrombolysis was measured in vivo in femoral artery. Our results showed that Zn2+, Fe3+ and Fe2+ inhibited tPA-induced thrombolysis, with Zn2+ and Fe2+ being the most effective. Metal ion chelating agent EDTA when it was co-applied with tPA significantly enhanced the tPA-induced thrombolysis. The chelation alone did not have noticeable thrombolytic effect. In in vivo study of tPA-induced thrombosis following femoral artery thrombosis, the co-application of tPA and EDTA achieved significant higher rate of reperfusion than that by tPA treatment alone, suggesting that ion chelation facilitates tPA-induced thrombolysis and potentially improves the safety of tPA application by reducing the necessary dose of tPA application. Our results suggest that the co-application of a chelator and tPA improves the efficacy and, potentially, safety of tPA application, by reducing the necessary dose of tPA for thrombolysis.

3.
Microsyst Nanoeng ; 7: 89, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34754504

RESUMO

In vivo, multiple biophysical cues provided by highly ordered connective tissues of the extracellular matrix regulate skeletal muscle cells to align in parallel with one another. However, in routine in vitro cell culture environments, these key factors are often missing, which leads to changes in cell behavior. Here, we present a simple strategy for using optical media discs with nanogrooves and other polymer-based substrates nanomolded from the discs to directly culture muscle cells to study their response to the effect of biophysical cues such as nanotopography and substrate stiffness. We extend the range of study of biophysical cues for myoblasts by showing that they can sense ripple sizes as small as a 100 nm width and a 20 nm depth for myotube alignment, which has not been reported previously. The results revealed that nanotopography and substrate stiffness regulated myoblast proliferation and morphology independently, with nanotopographical cues showing a higher effect. These biophysical cues also worked synergistically, and their individual effects on cells were additive; i.e., by comparing cells grown on different polymer-based substrates (with and without nanogrooves), the cell proliferation rate could be reduced by as much as ~29%, and the elongation rate could be increased as much as ~116%. Moreover, during myogenesis, muscle cells actively responded to nanotopography and consistently showed increases in fusion and maturation indices of ~28% and ~21%, respectively. Finally, under electrical stimulation, the contraction amplitude of well-aligned myotubes was found to be almost 3 times greater than that for the cells on a smooth surface, regardless of the substrate stiffness.

4.
Adv Mater ; : e2105539, 2021 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-34601764

RESUMO

Lead halide perovskite and organic solar cells (PSCs and OSCs) are considered as the prime candidates currently for clean energy applications due to their solution and low-temperature processibility. Nevertheless, the substantial photon loss in near-infrared (NIR) region and relatively large photovoltage deficit need to be improved to enable their uses in high-performance solar cells. To mitigate these disadvantages, low-bandgap organic bulk-heterojunction (BHJ) layer into inverted PSCs to construct facile hybrid solar cells (HSCs) is integrated. By optimizing the BHJ components, an excellent power conversion efficiency (PCE) of 23.80%, with a decent open-circuit voltage (Voc ) of 1.146 V and extended photoresponse over 950 nm for rigid HSCs is achieved. The resultant devices also exhibit superior long-term (over 1000 h) ambient- and photostability compared to those from single-component PSCs and OSCs. More importantly, a champion PCE of 21.73% and excellent mechanical durability can also be achieved in flexible HSCs, which is the highest efficiency reported for flexible solar cells to date. Taking advantage of these impressive device performances, flexible HSCs into a power source for wearable sensors to demonstrate real-time temperature monitoring are successfully integrated.

6.
Nature ; 597(7877): 503-510, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34552257

RESUMO

Large, distributed collections of miniaturized, wireless electronic devices1,2 may form the basis of future systems for environmental monitoring3, population surveillance4, disease management5 and other applications that demand coverage over expansive spatial scales. Aerial schemes to distribute the components for such networks are required, and-inspired by wind-dispersed seeds6-we examined passive structures designed for controlled, unpowered flight across natural environments or city settings. Techniques in mechanically guided assembly of three-dimensional (3D) mesostructures7-9 provide access to miniature, 3D fliers optimized for such purposes, in processes that align with the most sophisticated production techniques for electronic, optoelectronic, microfluidic and microelectromechanical technologies. Here we demonstrate a range of 3D macro-, meso- and microscale fliers produced in this manner, including those that incorporate active electronic and colorimetric payloads. Analytical, computational and experimental studies of the aerodynamics of high-performance structures of this type establish a set of fundamental considerations in bio-inspired design, with a focus on 3D fliers that exhibit controlled rotational kinematics and low terminal velocities. An approach that represents these complex 3D structures as discrete numbers of blades captures the essential physics in simple, analytical scaling forms, validated by computational and experimental results. Battery-free, wireless devices and colorimetric sensors for environmental measurements provide simple examples of a wide spectrum of applications of these unusual concepts.

7.
Nat Mater ; 20(11): 1559-1570, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34326506

RESUMO

Flexible electronic/optoelectronic systems that can intimately integrate onto the surfaces of vital organ systems have the potential to offer revolutionary diagnostic and therapeutic capabilities relevant to a wide spectrum of diseases and disorders. The critical interfaces between such technologies and living tissues must provide soft mechanical coupling and efficient optical/electrical/chemical exchange. Here, we introduce a functional adhesive bioelectronic-tissue interface material, in the forms of mechanically compliant, electrically conductive, and optically transparent encapsulating coatings, interfacial layers or supporting matrices. These materials strongly bond both to the surfaces of the devices and to those of different internal organs, with stable adhesion for several days to months, in chemistries that can be tailored to bioresorb at controlled rates. Experimental demonstrations in live animal models include device applications that range from battery-free optoelectronic systems for deep-brain optogenetics and subdermal phototherapy to wireless millimetre-scale pacemakers and flexible multielectrode epicardial arrays. These advances have immediate applicability across nearly all types of bioelectronic/optoelectronic system currently used in animal model studies, and they also have the potential for future treatment of life-threatening diseases and disorders in humans.

8.
Nat Neurosci ; 24(7): 1035-1045, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33972800

RESUMO

Advanced technologies for controlled delivery of light to targeted locations in biological tissues are essential to neuroscience research that applies optogenetics in animal models. Fully implantable, miniaturized devices with wireless control and power-harvesting strategies offer an appealing set of attributes in this context, particularly for studies that are incompatible with conventional fiber-optic approaches or battery-powered head stages. Limited programmable control and narrow options in illumination profiles constrain the use of existing devices. The results reported here overcome these drawbacks via two platforms, both with real-time user programmability over multiple independent light sources, in head-mounted and back-mounted designs. Engineering studies of the optoelectronic and thermal properties of these systems define their capabilities and key design considerations. Neuroscience applications demonstrate that induction of interbrain neuronal synchrony in the medial prefrontal cortex shapes social interaction within groups of mice, highlighting the power of real-time subject-specific programmability of the wireless optogenetic platforms introduced here.


Assuntos
Optogenética/instrumentação , Comportamento Social , Tecnologia sem Fio/instrumentação , Animais , Camundongos
9.
Nat Biomed Eng ; 5(7): 759-771, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34045731

RESUMO

Evaluating the biomechanics of soft tissues at depths well below their surface, and at high precision and in real time, would open up diagnostic opportunities. Here, we report the development and application of miniaturized electromagnetic devices, each integrating a vibratory actuator and a soft strain-sensing sheet, for dynamically measuring the Young's modulus of skin and of other soft tissues at depths of approximately 1-8 mm, depending on the particular design of the sensor. We experimentally and computationally established the operational principles of the devices and evaluated their performance with a range of synthetic and biological materials and with human skin in healthy volunteers. Arrays of devices can be used to spatially map elastic moduli and to profile the modulus depth-wise. As an example of practical medical utility, we show that the devices can be used to accurately locate lesions associated with psoriasis. Compact electronic devices for the rapid and precise mechanical characterization of living tissues could be used to monitor and diagnose a range of health disorders.


Assuntos
Técnicas Eletroquímicas/métodos , Pele/química , Adulto , Idoso , Animais , Fenômenos Biomecânicos , Módulo de Elasticidade , Técnicas Eletroquímicas/instrumentação , Humanos , Hidrogéis/química , Pessoa de Meia-Idade , Miniaturização , Pele/metabolismo , Suínos , Vibração , Adulto Jovem
10.
Nanotechnology ; 32(32)2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-33957611

RESUMO

Solution-processed organic thin-film transistors (OTFTs) are regarded as the promising candidates for low-cost gas sensors due to their advantages of high throughput, large-area and sensitive to various gas analytes. Microstructure control of organic active layers in OTFTs is an effective route to improve the sensing performance. In this work, we report a simple method to modify the morphology of 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) thin films via doping gold nanorods (Au NRs) for enhancing the performance of the corresponding OTFT sensors for nitrogen dioxide (NO2) detection. With the optimized doping ratio of Au nanorods, the TIPS-pentacene OTFT snesors not only exhibit a 3-fold increase in mobility, but also obtain a high sensitivity of 70% to 18 ppm NO2with a detection limit of 270 ppb. The microstructures and morphologies of the modified TIPS-pentacene thin film characterized by atomic force microscopy and field scanning electron microscope. The experimental results indicate that the proper addition of Au NRs could effectively regulate the grain size of TIPS-pentacene, and therein control the density of grain boundaries during the crystallization, which is essential for the high-performance gas sensors.

11.
Research (Wash D C) ; 2021: 2813643, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33796859

RESUMO

Sensitive detection of SARS-CoV-2 is of great importance for inhibiting the current pandemic of COVID-19. Here, we report a simple yet efficient platform integrating a portable and low-cost custom-made detector and a novel microwell array biochip for rapid and accurate detection of SARS-CoV-2. The instrument exhibits expedited amplification speed that enables colorimetric read-out within 25 minutes. A polymeric chip with a laser-engraved microwell array was developed to process the reaction between the primers and the respiratory swab RNA extracts, based on reverse transcriptase loop-mediated isothermal amplification (RT-LAMP). To achieve clinically acceptable performance, we synthesized a group of six primers to identify the conserved regions of the ORF1ab gene of SARS-CoV-2. Clinical trials were conducted with 87 PCR-positive and 43 PCR-negative patient samples. The platform demonstrated both high sensitivity (95.40%) and high specificity (95.35%), showing potentials for rapid and user-friendly diagnosis of COVID-19 among many other infectious pathogens.

12.
Chem Commun (Camb) ; 57(23): 2879-2882, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33616580

RESUMO

We report a micellar system to prepare Pt-TMDs composites with tunable Pt nanoparticles (NPs, 2-6 nm in size) on single-layer TMDs (MoS2, TiS2, TaS2) nanosheets. The Pt-MoS2 composites have shown excellent performance for the hydrogen evolution reaction (HER) with the Pt NPs exhibiting a volcano-type size effect toward HER activity due to the synergistic effects between the Pt NPs and MoS2.

13.
Sci Adv ; 7(7)2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33568482

RESUMO

Accurate, real-time monitoring of intravascular oxygen levels is important in tracking the cardiopulmonary health of patients after cardiothoracic surgery. Existing technologies use intravascular placement of glass fiber-optic catheters that pose risks of blood vessel damage, thrombosis, and infection. In addition, physical tethers to power supply systems and data acquisition hardware limit freedom of movement and add clutter to the intensive care unit. This report introduces a wireless, miniaturized, implantable optoelectronic catheter system incorporating optical components on the probe, encapsulated by soft biocompatible materials, as alternative technology that avoids these disadvantages. The absence of physical tethers and the flexible, biocompatible construction of the probe represent key defining features, resulting in a high-performance, patient-friendly implantable oximeter that can monitor localized tissue oxygenation, heart rate, and respiratory activity with wireless, real-time, continuous operation. In vitro and in vivo testing shows that this platform offers measurement accuracy and precision equivalent to those of existing clinical standards.

14.
Nanoscale ; 13(6): 3436-3453, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33538736

RESUMO

Most biofluids contain a wide variety of biochemical components that are closely related to human health. Analyzing biofluids, such as sweat and tears, may deepen our understanding in pathophysiologic conditions associated with human body, while providing a variety of useful information for the diagnosis and treatment of disorders and disease. Emerging classes of micro/nanostructured bioelectronic devices for biofluid detection represent a recent breakthrough development of critical importance in this context, including traditional biosensors (TBS) and micro/nanostructured biosensors (MNBS). Related biosensors are not restricted to flexible and wearable devices; solid devices are also involved here. This article is a timely overview of recent technical advances in this field, with an emphasis on the new insights of constituent materials, design architectures and detection methods of MNBS that support the necessary levels of biocompatibility, device functionality, and stable operation for component analysis. An additional section discusses and analyzes the existing challenges, possible solutions and future development of MNBS for detecting biofluids.


Assuntos
Técnicas Biossensoriais , Nanoestruturas , Dispositivos Eletrônicos Vestíveis , Humanos , Suor
15.
ACS Appl Mater Interfaces ; 13(2): 3445-3453, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33416304

RESUMO

Low-temperature, solution-processable, high-capacitance, and low-leakage gate dielectrics are of great interest for unconventional electronics. Here, we report a near room temperature ultraviolet densification (UVD) methodology for realizing high-performance organic-inorganic zirconia self-assembled nanodielectrics (UVD-ZrSANDs). These UVD-ZrSAND multilayers are grown from solution in ambient, densified by UV radiation, and characterized by X-ray reflectivity, atomic force microscopy, X-ray photoelectron spectroscopy, and capacitance measurements. The resulting UVD-ZrSAND films exhibit large capacitances of >700 nF/cm2 and low leakage current densities of <10-7 A/cm2, which rival or exceed those synthesized by traditional thermal methods. Both the p-type organic semiconductor pentacene and the n-type metal oxide semiconductor In2O3 were used to investigate UVD-ZrSANDs as the gate dielectric in thin-film transistors, affording mobilities of 0.58 and 26.21 cm2/(V s), respectively, at a low gate voltage of 2 V. These results represent a significant advance in fabricating ultra-thin high-performance dielectrics near room temperature and should facilitate their integration into diverse electronic technologies.

16.
IEEE Rev Biomed Eng ; 14: 48-70, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32396101

RESUMO

Coronavirus disease 2019 (COVID-19) has emerged as a pandemic with serious clinical manifestations including death. A pandemic at the large-scale like COVID-19 places extraordinary demands on the world's health systems, dramatically devastates vulnerable populations, and critically threatens the global communities in an unprecedented way. While tremendous efforts at the frontline are placed on detecting the virus, providing treatments and developing vaccines, it is also critically important to examine the technologies and systems for tackling disease emergence, arresting its spread and especially the strategy for diseases prevention. The objective of this article is to review enabling technologies and systems with various application scenarios for handling the COVID-19 crisis. The article will focus specifically on 1) wearable devices suitable for monitoring the populations at risk and those in quarantine, both for evaluating the health status of caregivers and management personnel, and for facilitating triage processes for admission to hospitals; 2) unobtrusive sensing systems for detecting the disease and for monitoring patients with relatively mild symptoms whose clinical situation could suddenly worsen in improvised hospitals; and 3) telehealth technologies for the remote monitoring and diagnosis of COVID-19 and related diseases. Finally, further challenges and opportunities for future directions of development are highlighted.


Assuntos
COVID-19/diagnóstico , Pandemias/prevenção & controle , Tecnologia/métodos , Telemedicina/métodos , COVID-19/virologia , Atenção à Saúde/métodos , Humanos , SARS-CoV-2/patogenicidade , Dispositivos Eletrônicos Vestíveis
17.
Micromachines (Basel) ; 11(12)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321695

RESUMO

Organic-inorganic hybrid perovskites have been widely used as light sensitive components for high-efficient photodetectors due to their superior optoelectronic properties. However, the unwanted crystallographic defects of perovskites typically result in high dark current, and thus limit the performance of the device. Herein, we introduce a simple route of microstructures control in MAPbI3 perovskites that associates with introducing an additive of 3,3,4,4-benzophenonetetracarboxylic dianhydridean (BPTCD) for crystallization adjustment of the perovskite film. The BPTCD additive can facilitate the formation of high-quality perovskite film with a compact and nearly pinhole-free morphology. Through characterizing the molecular interactions, it was found that the carbonyl groups in BPTCD is the key reason that promoted the nucleation and crystallization of MAPbI3. As a result, we obtained high-efficient and stable perovskite photodetectors with low dark current of 9.98 × 10-8 A at -0.5 V, an on/off ratio value of 103, and a high detectivity exceeding 1012 Jones over the visible region.

18.
ACS Appl Mater Interfaces ; 12(49): 54991-54999, 2020 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-33236878

RESUMO

Piezoelectric materials enable emerging self-powered wearable and implantable devices. The sol-gel technology with the lowest cost for large-scale production has shown its potential for producing high-quality PZT thin films. However, fabricating PZT films with a sufficient thickness for different application scenarios requires a long and repeated coating and heat-treatment process. The traditional solution-based method usually requires at least 20 coating cycles to fabricate 2 µm-thick PZT thin films. To save cost and improve fabrication efficiency, we develop a simplified thin-film fabrication method assisted by PZT powder. The new method can fabricate 2 µm-thick PZT films in a single step, one spin coating and annealing. Experiments indicate that the powder-based PZT thin films have porous structures and outstanding piezoelectric performances. The measured d33 of the powder-based PZT thin film is 47 pm/V. Both solution-based and powder-based PZT thin films show high flexibility and good fatigue resistance. Furthermore, we explore 2D mica as the substrate and achieve the transfer-free fabrication of flexible PZT thin-film nanogenerators that effectively simplify the complicated physical or chemical thin-film lift-off processes. The nanogenerator prototypes demonstrate the capability of accurately monitoring dynamic responses of flexible and soft human tissues.

19.
Research (Wash D C) ; 2020: 1085417, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33134931

RESUMO

Electronic skin made of thin, soft, stretchable devices that can mimic the human skin and reconstruct the tactile sensation and perception offers great opportunities for prosthesis sensing, robotics controlling, and human-machine interfaces. Advanced materials and mechanics engineering of thin film devices has proven to be an efficient route to enable and enhance flexibility and stretchability of various electronic skins; however, the density of devices is still low owing to the limitation in existing fabrication techniques. Here, we report a high-throughput one-step process to fabricate large tactile sensing arrays with a sensor density of 25 sensors/cm2 for electronic skin, where the sensors are based on intrinsically stretchable piezoelectric lead zirconate titanate (PZT) elastomer. The PZT elastomer sensor arrays with great uniformity and passive-driven manner enable high-resolution tactile sensing, simplify the data acquisition process, and lower the manufacturing cost. The high-throughput fabrication process provides a general platform for integrating intrinsically stretchable materials into large area, high device density soft electronics for the next-generation electronic skin.

20.
Nat Commun ; 11(1): 2405, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32415064

RESUMO

Fiber-based electronics enabling lightweight and mechanically flexible/stretchable functions are desirable for numerous e-textile/e-skin optoelectronic applications. These wearable devices require low-cost manufacturing, high reliability, multifunctionality and long-term stability. Here, we report the preparation of representative classes of 3D-inorganic nanofiber network (FN) films by a blow-spinning technique, including semiconducting indium-gallium-zinc oxide (IGZO) and copper oxide, as well as conducting indium-tin oxide and copper metal. Specifically, thin-film transistors based on IGZO FN exhibit negligible performance degradation after one thousand bending cycles and exceptional room-temperature gas sensing performance. Owing to their great stretchability, these metal oxide FNs can be laminated/embedded on/into elastomers, yielding multifunctional single-sensing resistors as well as fully monolithically integrated e-skin devices. These can detect and differentiate multiple stimuli including analytes, light, strain, pressure, temperature, humidity, body movement, and respiratory functions. All of these FN-based devices exhibit excellent sensitivity, response time, and detection limits, making them promising candidates for versatile wearable electronics.


Assuntos
Nanopartículas Metálicas/química , Nanofibras/química , Dispositivos Eletrônicos Vestíveis , Consumo de Bebidas Alcoólicas , Técnicas Biossensoriais , Testes Respiratórios , Cobre/química , Elastômeros , Etanol/análise , Análise de Elementos Finitos , Gálio/química , Humanos , Índio/química , Teste de Materiais , Movimento (Física) , Poliestirenos/química , Semicondutores , Espectrofotometria Ultravioleta , Temperatura , Têxteis , Óxido de Zinco/química
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