By analyzing facial features to perform expression recognition and health monitoring, facial perception plays a pivotal role in noninvasive, real-time disease diagnosis and prevention. Current perception routes are limited by structural complexity and the necessity of a power supply, making timely and accurate monitoring difficult. Herein, a self-powered poly(vinyl alcohol)-gellan gum-glycerol thermogalvanic gel patch enabling facial perception is developed for monitoring emotions and atypical pathological states.
View Article and Find Full Text PDFWearable devices equipped with high-performance flexible sensors that can identify diverse physical information free from batteries are playing an indispensable role in various fields. However, previous studies on flexible sensors have primarily focused on their elasticity and temperature-sensing capability, with few reports on material identification. In this paper, a thermogalvanic dual-network hydrogel is fabricated with [Fe(CN)] as a redox couple and lithium magnesium silicate, Gdm and lithium bromide as key electrolytes to optimize the interconnected porous structure of the gel, which shows excellent mechanical and thermoelectric properties with a thermopower as high as 4.
View Article and Find Full Text PDFBiotechnol Bioeng
December 2024
3D bioprinting technology is widely used in biomedical fields such as tissue regeneration and constructing pathological model. The prevailing printing technique is extrusion-based bioprinting. In this printing method, the bioink needs to meet both printability and functionality, which are often conflicting requirements.
View Article and Find Full Text PDFDirect and consistent monitoring of respiratory patterns is crucial for disease prognostication. Although the wired clinical respiratory monitoring apparatus can operate accurately, the existing defects are evident, such as the indispensability of an external power supply, low mobility, poor comfort, and limited monitoring timeframes. Here, we present a self-powered in-nostril hydrogel sensor for long-term non-irritant anti-interference respiratory monitoring, which is developed from a dual-network binary-solvent thermogalvanic polyvinyl alcohol hydrogel fiber (d = 500 μm, L=30 mm) with Fe/Fe ions serving as a redox couple, which can generate a thermoelectrical signal in the nasal cavity based on the temperature difference between the exhaled gas and skin as well as avoid interference from the external environment.
View Article and Find Full Text PDFNatural hydrogels are widely employed in tissue engineering and have excellent biodegradability and biocompatibility. Unfortunately, the utilization of such hydrogels in the field of three-dimensional (3D) printing nasal cartilage is constrained by their subpar mechanical characteristics. In this study, we provide a multicrosslinked network hybrid ink made of photocurable gelatin, hyaluronic acid, and acrylamide (AM).
View Article and Find Full Text PDFIdentity recognition as the first barrier of intelligent security plays a vital role, which is facing new challenges that are unable to meet the need of intelligent era due to low accuracy, complex configuration and dependence on power supply. Here, a finger temperature-driven intelligent identity recognition strategy is presented based on a thermogalvanic hydrogel (TGH) by actively discerning biometric characteristics of fingers. The TGH is a dual network PVA/Agar hydrogel in an HO/glycerol binary solvent with [Fe(CN)] as a redox couple.
View Article and Find Full Text PDFSensing of both temperature and strain is crucial for various diagnostic and therapeutic purposes. Here, we present a novel hydrogel-based electronic skin (e-skin) capable of dual-mode sensing of temperature and strain. The thermocouple ion selected for this study is the iodine/triiodide (I/I) redox couple, which is a common component in everyday disinfectants.
View Article and Find Full Text PDFAesthetic Plast Surg
August 2024
Introduction: Since 3D printing can be used to design implants according to the specific conditions of patients, it has become an emerging technology in tissue engineering and regenerative medicine. How to improve the mechanical, elastic and adhesion properties of 3D-printed photocrosslinked hydrogels is the focus of cartilage tissue repair and reconstruction research.
Materials And Methods: We established a strategy for toughening hydrogels by mixing GelMA-DOPA (GD), which is prepared by coupling dopamine (DA) with GelMA, with HAMA, bacterial cellulose (BC) to produce composite hydrogels (HB-GD).
Electronic skins (e-skins) are being extensively researched for their ability to recognize physiological data and deliver feedback via electrical signals. However, their wide range of applications is frequently restricted by the indispensableness of external power supplies and single sensory function. Here, we report a passive multimodal e-skin for real-time human health assessment based on a thermoelectric hydrogel.
View Article and Find Full Text PDFSerious climate changes and energy-related environmental problems are currently critical issues in the world. In order to reduce carbon emissions and save our environment, renewable energy harvesting technologies will serve as a key solution in the near future. Among them, triboelectric nanogenerators (TENGs), which is one of the most promising mechanical energy harvesters by means of contact electrification phenomenon, are explosively developing due to abundant wasting mechanical energy sources and a number of superior advantages in a wide availability and selection of materials, relatively simple device configurations, and low-cost processing.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2022
As a low-grade sustainable heat source, the breath waste heat exhaled by human bodies is always ignored, although producing a greater temperature than ambient. Converting this heat into electric energy for use as power sources or detecting signals is extremely important in cutting-edge wearable medicine. This heat-to-electricity conversion is possible with thermogalvanic hydrogels.
View Article and Find Full Text PDFSelf-powered wearable electronics to convert mechanical and thermal energy into electrical energy are important for biomedical monitoring, which highly require good flexibility, comfortability, signal sensitivity, and accuracy. In this work, composite nanofiber mats of polyacrylonitrile (PAN) and trimethylamine borane (TMAB) were prepared by electrospinning, which exhibited excellent piezoelectric and pyroelectric abilities in harvesting mechanical and thermal energy. The PAN/TMAB-4 nanofiber mats not only generated a high voltage of up to 2.
View Article and Find Full Text PDFEnviron Sci Ecotechnol
April 2022
The energy consumption in building ventilation, air, and heating conditioning systems, accounts for about 25% of the overall energy consumption in modern society. Therefore, cutting carbon emissions and reducing energy consumption is a growing priority in building construction. Electrochromic devices (ECDs) are considered to be a highly promising energy-saving technology, due to their simple structure, active control, and low energy input characteristics.
View Article and Find Full Text PDFMicromachines (Basel)
July 2022
The water covering the Earth's surface not only supports life but also contains a tremendous amount of energy. Water energy is the most important and widely used renewable energy source in the environment, and the ability to extract the mechanical energy of water is of particular interest since moving water is ubiquitous and abundant, from flowing rivers to falling rain drops. In recent years, triboelectric nanogenerators (TENGs) have been promising for applications in harvesting kinetic energy from water due to their merits of low cost, light weight, simple structure, and abundant choice of materials.
View Article and Find Full Text PDFThe adaptable monitoring of the ubiquitous magnetic field is of great importance not only for scientific research but also for industrial production. However, the current detecting techniques are unwieldly and lack essential mobility owing to the complex configuration and indispensability of the power source. Here, we have constructed a self-powered magnetic sensor based on a subtle triboelectric nanogenerator (TENG) that consists of a magnetorheological elastomer (MRE).
View Article and Find Full Text PDFThere is always a temperature difference of more than 10 degrees between the human body, as a sustainable heat source, and the ambient temperature. Converting body heat into electricity that in turn is used to drive personal medical electronics is of significance in smart wearable medicine. To avoid the frangibility and complex preparation of traditional thermoelectric materials, we fabricated a gel electrolyte-based thermogalvanic generator with Fe/Fe as a redox pair, which presents not only moderate thermoelectric performance but also excellent flexibility.
View Article and Find Full Text PDFBeilstein J Nanotechnol
November 2020
The tracking of body motion, such as bending or twisting, plays an important role in modern sign language translation. Here, a subtle flexible self-powered piezoelectric sensor (PES) made of graphene (GR)-doped polyvinylidene fluoride (PVDF) nanofibers is reported. The PES exhibits a high sensitivity to pressing and bending, and there is a stable correlation between bending angle and piezoelectric voltage.
View Article and Find Full Text PDFNanomaterial-based flexible strain sensors have developed rapidly in recent years. Here, we propose a flexible strain sensor based on polydimethylsiloxane with carbon nanotubes (CNTs) and graphene quantum dots (GQDs). Different weight ratios of CNTs and GQDs were used as the sensitive units of the strain sensors.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2019
The application of the serpentine mesh layout in stretchable electronics provides a feasible method to achieve the desired stretchability by structural design instead of modifying the intrinsic mechanical properties of the applied materials. However, previous works using the serpentine layout mainly focused on the optimization of structural stretchability. In this paper, the serpentine mesh design concept is used to transform the high-performance but hard-to-stretch piezoelectric film into a stretchable form.
View Article and Find Full Text PDFInterface engineering is an important method to modulate electronic structures for improving the physical properties of semiconductors as well as designing novel devices. Recently, development of flexible electronic devices based on inorganic thin films on flexible substrates, which provides solutions to meet the emerging technological demands, may also expend the methodology of interface engineering. Herein, a semitransparent photodetector based on an indium-tin oxide (ITO)-on-silicon (Si) heterojunction was fabricated on a flexible substrate and investigated under mechanical bending strains.
View Article and Find Full Text PDFSoft neural electrode arrays that are mechanically matched between neural tissues and electrodes offer valuable opportunities for the development of disease diagnose and brain computer interface systems. Here, a thermal release transfer printing method for fabrication of stretchable bioelectronics, such as soft neural electrode arrays, is presented. Due to the large, switchable and irreversible change in adhesion strength of thermal release tape, a low-cost, easy-to-operate, and temperature-controlled transfer printing process can be achieved.
View Article and Find Full Text PDFA new implantable capacitive electrode array for electrocorticography signal recording is developed with ferroelectric ceramic/polymer composite. This ultrathin and electrically safe capacitive electrode array is capable of attaching to the biological tissue conformably. The barium titanate/polyimide (BaTiO /PI) nanocomposite with high dielectric constant is successfully synthesized and employed as the ultrathin dielectric layer of the capacitive BaTiO /PI electrode array.
View Article and Find Full Text PDFRecent progresses on the Kirigami-inspired method provide a new idea to assemble three-dimensional (3D) functional structures with conventional materials by releasing the prestrained elastomeric substrates. In this paper, highly stretchable serpentine-like antenna is fabricated by a simple and quick "Cut-Transfer-Release" method for assembling stretchable 3D functional structures on an elastomeric substrate with a controlled shape. The mechanical reliability of the serpentine-like 3D stretchable antenna is evaluated by the finite element method and experiments.
View Article and Find Full Text PDFMeteorologic monitoring plays a key role on weather forecast and disaster warning and deeply relies on various sensor networks. It is an optimal choice that grabbing the environmental energy around sensors for driving sensor network. Here, we demonstrate a self-powered, wireless, remote meteorologic monitoring system based on an innovative TENG.
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