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1.
Proc Natl Acad Sci U S A ; 119(23): e2204852119, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-35648822

RESUMO

Cephalopod (e.g., squid, octopus, etc.) skin is a soft cognitive organ capable of elastic deformation, visualizing, stealth, and camouflaging through complex biological processes of sensing, recognition, neurologic processing, and actuation in a noncentralized, distributed manner. However, none of the existing artificial skin devices have shown distributed neuromorphic processing and cognition capabilities similar to those of a cephalopod skin. Thus, the creation of an elastic, biaxially stretchy device with embedded, distributed neurologic and cognitive functions mimicking a cephalopod skin can play a pivotal role in emerging robotics, wearables, skin prosthetics, bioelectronics, etc. This paper introduces artificial neuromorphic cognitive skins based on arrayed, biaxially stretchable synaptic transistors constructed entirely out of elastomeric materials. Systematic investigation of the synaptic characteristics such as the excitatory postsynaptic current, paired-pulse facilitation index of the biaxially stretchable synaptic transistor under various levels of biaxial mechanical strain sets the operational foundation for stretchy distributed synapse arrays and neuromorphic cognitive skin devices. The biaxially stretchy arrays here achieved neuromorphic cognitive functions, including image memorization, long-term memorization, fault tolerance, programming, and erasing functions under 30% biaxial mechanical strain. The stretchy neuromorphic imaging sensory skin devices showed stable neuromorphic pattern reinforcement performance under both biaxial and nonuniform local deformation.


Assuntos
Órgãos Artificiais , Robótica , Pele , Sinapses , Animais , Cefalópodes , Cognição , Pele/inervação , Transistores Eletrônicos
2.
Adv Funct Mater ; 33(2)2023 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-36816838

RESUMO

Peripheral nerve transection has a high prevalence and results in functional loss of affected limbs. The current clinical treatment using suture anastomosis significantly limits nerve recovery due to severe inflammation, secondary damage, and fibrosis. Fibrin glue, a commercial nerve adhesive as an alternative, avoids secondary damage but suffers from poor adhesion strength. To address their limitations, a highly efficacious nerve adhesive based on dual-crosslinking of dopamine-isothiocyanate modified hyaluronic acid and decellularized nerve matrix is reported in this paper. This dual-network nerve adhesive (DNNA) shows controllable gelation behaviors feasible for surgical applications, robust adhesion strength, and promoted axonal outgrowth in vitro. The in vivo therapeutic efficacy is tested using a rat-based sciatic nerve transection model. The DNNA decreases fibrosis and accelerates axon/myelin debris clearance at 10 days post-surgery, compared to suture and commercial fibrin glue treatments. At 10 weeks post-surgery, the strong adhesion and bioactivity allow DNNA to significantly decrease intraneural inflammation and fibrosis, enhance axon connection and remyelination, aid motor and sensory function recovery, as well as improve muscle contraction, compared to suture and fibrin treatments. Overall, this dual-network hydrogel with robust adhesion provides a rapid and highly efficacious nerve transection treatment to facilitate nerve repair and neuromuscular function recovery.

3.
Small ; 19(44): e2302072, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37431202

RESUMO

Spectrally selective narrowband photodetection is critical for near-infrared (NIR) imaging applications, such as for communicationand night-vision utilities. It is a long-standing challenge for detectors based on silicon, to achieve narrowband photodetection without integrating any optical filters. Here, this work demonstrates a NIR nanograting Si/organic (PBDBT-DTBT:BTP-4F) heterojunction photodetector (PD), which for the first time obtains the full-width-at-half-maximum (FWHM) of only 26 nm and fast response of 74 µs at 895 nm. The response peak can be successfully tailored from 895 to 977 nm. The sharp and narrow response NIR peak is inherently attributed to the coherent overlapping between the NIR transmission spectrum of organic layer and diffraction enhanced absorption peak of patterned nanograting Si substrates. The finite difference time domain (FDTD) physics calculation confirms the resonant enhancement peaks, which is well consistent with the experiment results. Meanwhile, the relative characterization indicates that the introduction of the organic film can promote carrier transfer and charge collection, facilitating efficient photocurrent generation. This new device design strategy opens up a new window in developing low-cost sensitive NIR narrowband detection.

4.
Small ; 18(36): e2107099, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36073141

RESUMO

The need to develop wearable devices for personal health monitoring, diagnostics, and therapy has inspired the production of innovative on-demand, customizable technologies. Several of these technologies enable printing of raw electronic materials directly onto biological organs and tissues. However, few of them have been thoroughly investigated for biocompatibility of the raw materials on the cellular, tissue, and organ levels or with different cell types. In addition, highly accurate multiday in vivo monitoring using such on-demand, in situ fabricated devices has yet to be done. Presented herein is the first fully biocompatible, on-skin fabricated electronics for multiple cell types and tissues that can capture electrophysiological signals with high fidelity. While also demonstrating improved mechanical and electrical properties, the drawn-on-skin ink retains its properties under various writing conditions, which minimizes the variation in electrical performance. Furthermore, the drawn-on-skin ink shows excellent biocompatibility with cardiomyocytes, neurons, mice skin tissue, and human skin. The high signal-to-noise ratios of the electrophysiological signals recorded with the DoS sensor over multiple days demonstrate its potential for personalized, long-term, and accurate electrophysiological health monitoring.


Assuntos
Tinta , Dispositivos Eletrônicos Vestíveis , Animais , Eletrônica , Eletrofisiologia , Humanos , Camundongos , Pele
5.
Nat Mater ; 22(7): 801-802, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37380831
6.
Proc Natl Acad Sci U S A ; 111(36): 12998-3003, 2014 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-25136094

RESUMO

Octopus, squid, cuttlefish, and other cephalopods exhibit exceptional capabilities for visually adapting to or differentiating from the coloration and texture of their surroundings, for the purpose of concealment, communication, predation, and reproduction. Long-standing interest in and emerging understanding of the underlying ultrastructure, physiological control, and photonic interactions has recently led to efforts in the construction of artificial systems that have key attributes found in the skins of these organisms. Despite several promising options in active materials for mimicking biological color tuning, existing routes to integrated systems do not include critical capabilities in distributed sensing and actuation. Research described here represents progress in this direction, demonstrated through the construction, experimental study, and computational modeling of materials, device elements, and integration schemes for cephalopod-inspired flexible sheets that can autonomously sense and adapt to the coloration of their surroundings. These systems combine high-performance, multiplexed arrays of actuators and photodetectors in laminated, multilayer configurations on flexible substrates, with overlaid arrangements of pixelated, color-changing elements. The concepts provide realistic routes to thin sheets that can be conformally wrapped onto solid objects to modulate their visual appearance, with potential relevance to consumer, industrial, and military applications.


Assuntos
Adaptação Ocular , Cefalópodes/anatomia & histologia , Eletrônica/instrumentação , Óptica e Fotônica/instrumentação , Pele/anatomia & histologia , Animais , Cor
7.
Soft Matter ; 11(40): 7953-9, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26323563

RESUMO

We describe and characterize elementary designs for electrochemical micro- and macro-scale chemomechanical hydrogel actuators. The actuation of a pH-sensitive cross-linked polyacrylic acid (PAA) hydrogel is driven in the model devices through the oxygen reduction reaction (ORR) occurring at the electrodes of an embedded Au mesh micro-electrochemical array. Proton consumption by the ORR at the cathode of the embedded electrochemical cell leads to the formation of a localized pH gradient that in turn drives the strain response in the composite actuators. The dynamics result from the ionization of the carboxylic acid moieties of the PAA network in the high pH region, yielding an osmotic pressure that drives a volumetric expansion due to water imbibition. This system actuates both stably and reversibly; when the electrochemically-induced ORR is halted, the localized pH gradient dissipates due to diffusive mixing, which in turn relaxes the induced strains. Two approaches to the fabrication of hydrogel actuators were examined in this work. The first method adopted a design based on small flagella (∼0.2 mm × 1.5 mm × 60 µm, width × length × height) in which the actuating PAA structures are molded atop a set of fixed electrodes mounted on a supporting substrate. These hydrogel actuators show fast, large-amplitude, and largely reversible responses in the ORR mediated chemomechanical dynamics. We also investigated larger hydrogel actuators (∼4.5 mm × 11 mm × 1 mm, width × length × height), based on an autonomous design that embeds an open mesh stretchable micro-electrode array within the hydrogel. The significant and design-dependent impacts of mass transfer on the chemomechanical dynamics are evidenced in each case, a feature examined to elucidate more efficient mesoscopic design rules for actuators of this form.

8.
ACS Nano ; 18(10): 7580-7595, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38422400

RESUMO

The lack of both digital light processing (DLP) compatible and biocompatible photopolymers, along with inappropriate material properties required for wearable sensor applications, substantially hinders the employment of DLP 3D printing in the fabrication of multifunctional hydrogels. Herein, we discovered and implemented a photoreactive poloxamer derivative, Pluronic F-127 diacrylate, which overcomes these limitations and is optimized to achieve DLP 3D printed micelle-based hydrogels with high structural complexity, resolution, and precision. In addition, the dehydrated hydrogels exhibit a shape-memory effect and are conformally attached to the geometry of the detection point after rehydration, which implies the 4D printing characteristic of the fabrication process and is beneficial for the storage and application of the device. The excellent cytocompatibility and in vivo biocompatibility further strengthen the potential application of the poloxamer micelle-based hydrogels as a platform for multifunctional wearable systems. After processing them with a lithium chloride (LiCl) solution, multifunctional conductive ionic hydrogels with antifreezing and antiswelling properties along with good transparency and water retention are easily prepared. As capacitive flexible sensors, the DLP 3D printed micelle-based hydrogel devices exhibit excellent sensitivity, cycling stability, and durability in detecting multimodal deformations. Moreover, the DLP 3D printed conductive hydrogels are successfully applied as real-time human motion and tactile sensors with satisfactory sensing performances even in a -20 °C low-temperature environment.


Assuntos
Micelas , Dispositivos Eletrônicos Vestíveis , Humanos , Poloxâmero , Condutividade Elétrica , Hidrogéis , Impressão Tridimensional
9.
Natl Sci Rev ; 11(6): nwae050, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38707205

RESUMO

High intraocular pressure (IOP) is one of the high-risk pathogenic factors of glaucoma. Existing methods of IOP measurement are based on the direct interaction with the cornea. Commercial ophthalmic tonometers based on snapshot measurements are expensive, bulky, and their operation requires trained personnel. Theranostic contact lenses are easy to use, but they may block vision and cause infection. Here, we report a sensory system for IOP assessment that uses a soft indentor with two asymmetrically deployed iontronic flexible pressure sensors to interact with the eyelid-eyeball in an eye-closed situation. Inspired by human fingertip assessment of softness, the sensory system extracts displacement-pressure information for soft evaluation, achieving high accuracy IOP monitoring (>96%). We further design and custom-make a portable and wearable ophthalmic tonometer based on the sensory system and demonstrate its high efficacy in IOP screening. This sensory system paves a way towards cost-effective, robust, and reliable IOP monitoring.

10.
Npj Flex Electron ; 7(1): 32, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38665149

RESUMO

In recent years, wearable bioelectronics has rapidly expanded for diagnosing, monitoring, and treating various pathological conditions from the skin surface. Although the devices are typically prefabricated as soft patches for general usage, there is a growing need for devices that are customized in situ to provide accurate data and precise treatment. In this perspective, the state-of-the-art in situ fabricated wearable bioelectronics are summarized, focusing primarily on Drawn-on-Skin (DoS) bioelectronics and other in situ fabrication methods. The advantages and limitations of these technologies are evaluated and potential future directions are suggested for the widespread adoption of these technologies in everyday life.

11.
Nat Commun ; 14(1): 1257, 2023 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-36878901

RESUMO

A flexible mechanoluminophore device that is capable of converting mechanical energy into visualizable patterns through light-emission holds great promise in many applications, such as human-machine interfaces, Internet of Things, wearables, etc. However, the development has been very nascent, and more importantly, existing mechanoluminophore materials or devices emit light that cannot be discernible under ambient light, in particular with slight applied force or deformation. Here we report the development of a low-cost flexible organic mechanoluminophore device, which is constructed based on the multi-layered integration of a high-efficiency, high-contrast top-emitting organic light-emitting device and a piezoelectric generator on a thin polymer substrate. The device is rationalized based on a high-performance top-emitting organic light-emitting device design and maximized piezoelectric generator output through a bending stress optimization and have demonstrated that it is discernible under an ambient illumination as high as 3000 lux. A flexible multifunctional anti-counterfeiting device is further developed by integrating patterned electro-responsive and photo-responsive organic emitters onto the flexible organic mechanoluminophore device, capable of converting mechanical, electrical, and/or optical inputs into light emission and patterned displays.

12.
Adv Sci (Weinh) ; 10(7): e2203943, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36646501

RESUMO

Continuous monitoring of glucose allows diabetic patients to better maintain blood glucose level by altering insulin dosage or diet according to prevailing glucose values and thus to prevent potential hyperglycemia and hypoglycemia. However, current continuous glucose monitoring (CGM) relies mostly on enzyme electrodes or micro-dialysis probes, which suffer from insufficient stability, susceptibility to corrosion of electrodes, weak or inconsistent correlation, and inevitable interference. A fluorescence-based glucose sensor in the skin will likely be more stable, have improved sensitivity, and can resolve the issues of electrochemical interference from the tissue. This study develops a fluorescent nanodiamond boronic hydrogel system in porous microneedles for CGM. Fluorescent nanodiamond is one of the most photostable fluorophores with superior biocompatibility. When surface functionalized, the fluorescent nanodiamond can integrate with boronic polymer and form a hydrogel, which can produce fluorescent signals in response to environmental glucose concentration. In this proof-of-concept study, the strategy for building a miniatured device with fluorescent nanodiamond hydrogel is developed. The device demonstrates remarkable long-term photo and signal stability in vivo with both small and large animal models. This study presents a new strategy of fluorescence based CGM toward treatment and control of diabetes.


Assuntos
Glicemia , Nanodiamantes , Animais , Automonitorização da Glicemia , Hidrogéis , Glucose
13.
PNAS Nexus ; 2(1): pgac291, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36712933

RESUMO

Accurate anatomical matching for patient-specific electromyographic (EMG) mapping is crucial yet technically challenging in various medical disciplines. The fixed electrode construction of multielectrode arrays (MEAs) makes it nearly impossible to match an individual's unique muscle anatomy. This mismatch between the MEAs and target muscles leads to missing relevant muscle activity, highly redundant data, complicated electrode placement optimization, and inaccuracies in classification algorithms. Here, we present customizable and reconfigurable drawn-on-skin (DoS) MEAs as the first demonstration of high-density EMG mapping from in situ-fabricated electrodes with tunable configurations adapted to subject-specific muscle anatomy. The DoS MEAs show uniform electrical properties and can map EMG activity with high fidelity under skin deformation-induced motion, which stems from the unique and robust skin-electrode interface. They can be used to localize innervation zones (IZs), detect motor unit propagation, and capture EMG signals with consistent quality during large muscle movements. Reconfiguring the electrode arrangement of DoS MEAs to match and extend the coverage of the forearm flexors enables localization of the muscle activity and prevents missed information such as IZs. In addition, DoS MEAs customized to the specific anatomy of subjects produce highly informative data, leading to accurate finger gesture detection and prosthetic control compared with conventional technology.

14.
Sci Adv ; 9(9): eadf8831, 2023 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-36867698

RESUMO

Iontronic pressure sensors are promising in robot haptics because they can achieve high sensing performance using nanoscale electric double layers (EDLs) for capacitive signal output. However, it is challenging to achieve both high sensitivity and high mechanical stability in these devices. Iontronic sensors need microstructures that offer subtly changeable EDL interfaces to boost sensitivity, while the microstructured interfaces are mechanically weak. Here, we embed isolated microstructured ionic gel (IMIG) in a hole array (28 × 28) of elastomeric matrix and cross-link the IMIGs laterally to achieve enhanced interfacial robustness without sacrificing sensitivity. The embedded configuration toughens and strengthens the skin by pinning cracks and by the elastic dissipation of the interhole structures. Furthermore, cross-talk between the sensing elements is suppressed by isolating the ionic materials and by designing a circuit with a compensation algorithm. We have demonstrated that the skin is potentially useful for robotic manipulation tasks and object recognition.

15.
Nat Commun ; 14(1): 1972, 2023 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-37031227

RESUMO

Spherical geometry, adaptive optics, and highly dense network of neurons bridging the eye with the visual cortex, are the primary features of human eyes which enable wide field-of-view (FoV), low aberration, excellent adaptivity, and preprocessing of perceived visual information. Therefore, fabricating spherical artificial eyes has garnered enormous scientific interest. However, fusing color vision, in-device preprocessing and optical adaptivity into spherical artificial eyes has always been a tremendous challenge. Herein, we demonstrate a bionic eye comprising tunable liquid crystal optics, and a hemispherical neuromorphic retina with filter-free color vision, enabled by wavelength dependent bidirectional synaptic photo-response in a metal-oxide nanotube/perovskite nanowire hybrid structure. Moreover, by tuning the color selectivity with bias, the device can reconstruct full color images. This work demonstrates a unique approach to address the color vision and optical adaptivity issues associated with artificial eyes that can bring them to a new level approaching their biological counterparts.


Assuntos
Visão de Cores , Nanofios , Próteses Visuais , Humanos , Retina/fisiologia , Óxidos
16.
Sci Adv ; 9(46): eadh8083, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37967195

RESUMO

The advent of implantable bioelectronic devices offers prospective solutions toward health monitoring and disease diagnosis and treatments. However, advances in power modules have lagged far behind the tissue-integrated sensor nodes and circuit units. Here, we report a soft implantable power system that monolithically integrates wireless energy transmission and storage modules. The energy storage unit comprises biodegradable Zn-ion hybrid supercapacitors that use molybdenum sulfide (MoS2) nanosheets as cathode, ion-crosslinked alginate gel as electrolyte, and zinc foil as anode, achieving high capacitance (93.5 mF cm-2) and output voltage (1.3 V). Systematic investigations have been conducted to elucidate the charge storage mechanism of the supercapacitor and to assess the biodegradability and biocompatibility of the materials. Furthermore, the wirelessly transmitted energy can not only supply power directly to applications but also charge supercapacitors to ensure a constant, reliable power output. Its power supply capabilities have also been successfully demonstrated for controlled drug delivery.


Assuntos
Alginatos , Próteses e Implantes , Estudos Prospectivos , Sistemas de Liberação de Medicamentos , Zinco
17.
Sci Adv ; 8(47): eade4284, 2022 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-36417509

RESUMO

A fully rubbery stretchable diode, particularly entirely based on stretchy materials, is a crucial device for stretchable integrated electronics in a wide range of applications, ranging from energy to biomedical, to integrated circuits, and to robotics. However, its development has been very nascent. Here, we report a fully rubbery Schottky diode constructed all based on stretchable electronic materials, including a liquid metal cathode, a rubbery semiconductor, and a stretchable anode. The rubbery Schottky diode exhibited a forward current density of 6.99 × 10-3 A/cm2 at 5 V and a rectification ratio of 8.37 × 104 at ±5 V. Stretchy rectifiers and logic gates based on the rubbery Schottky diodes were developed and could retain their electrical performance even under 30% tensile stretching. With the rubbery diodes, fully rubbery integrated electronics, including an active matrix multiplexed tactile sensor and a triboelectric nanogenerator-based power management system, are further demonstrated.

18.
Light Sci Appl ; 11(1): 59, 2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35288540

RESUMO

As a primary anticounterfeiting technology, most paper anticounterfeiting devices take advantage of photoresponsive behaviors of certain security materials or structures, thus featuring low-security threshold, which has been a critical global issue. To incorporate optoelectronic devices into existing anticounterfeiting technology suggests a feasible avenue to address this challenge. Here we report a high-performance organic light-emitting paper-based flexible anticounterfeiting (FAC) device with multiple stimuli-responsiveness, including light, electricity, and their combination. Without sacrificing the preexisted security information on the paper, we fabricate FAC device in a facile, low-cost yet high-fidelity fashion by integrating patterned electro-responsive and photo-responsive organic emitters onto paper substrates. By introducing optical microcavities, the FAC device shows considerable color shift upon different viewing angle and applied voltage, which is easily discernible by naked eyes. Notably, the FAC device is bendable, unclonable, and durable (a half-lifetime over 4000 hours at 100 cd m-2).

19.
Soft Sci ; 22022.
Artigo em Inglês | MEDLINE | ID: mdl-37056725

RESUMO

Wound healing is one of the most complex processes in the human body, supported by many cellular events that are tightly coordinated to repair the wound efficiently. Chronic wounds have potentially life-threatening consequences. Traditional wound dressings come in direct contact with wounds to help them heal and avoid further complications. However, traditional wound dressings have some limitations. These dressings do not provide real-time information on wound conditions, leading clinicians to miss the best time for adjusting treatment. Moreover, the current diagnosis of wounds is relatively subjective. Wearable electronics have become a unique platform to potentially monitor wound conditions in a continuous manner accurately and even to serve as accelerated healing vehicles. In this review, we briefly discuss the wound status with some objective parameters/biomarkers influencing wound healing, followed by the presentation of various novel wearable devices used for monitoring wounds and accelerating wound healing. We further summarize the associated device working principles. This review concludes by highlighting some major challenges in wearable devices toward wound healing that need to be addressed by the research community.

20.
iScience ; 25(11): 105402, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36388958

RESUMO

Currently, there are no treatments that ameliorate cardiac cell death, the underlying basis of cardiovascular disease. An unexplored cell type in cardiac regeneration is cardiac Purkinje cells; specialized cells from the cardiac conduction system (CCS) responsible for propagating electrical signals. Purkinje cells have tremendous potential as a regenerative treatment because they may intrinsically integrate with the CCS of a recipient myocardium, resulting in more efficient electrical conduction in diseased hearts. This study is the first to demonstrate an effective protocol for the direct reprogramming of human cardiomyocytes into cardiac Purkinje-like cells using small molecules. The cells generated were genetically and functionally similar to native cardiac Purkinje cells, where expression of key cardiac Purkinje genes such as CNTN2, ETV1, PCP4, IRX3, SCN5a, HCN2 and the conduction of electrical signals with increased velocity was observed. This study may help to advance the quest to finding an optimized cell therapy for heart regeneration.

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