Textile‐based triboelectric nanogenerators integrated with 2D materials

The human body continuously generates ambient mechanical energy through diverse movements, such as walking and cycling, which can be harvested via various renewable energy harvesting mechanisms. Triboelectric Nanogenerator (TENG) stands out as one of the most promising emerging renewable energy harvesting technologies for wearable applications due to its ability to harness various forms of mechanical energies, including vibrations, pressure, and rotations, and convert them into electricity. However, their application is limited due to challenges in achieving performance, flexibility, low power consumption, and durability. Here, we present a robust and high-performance self-powered system integrated into cotton fabric by incorporating a textile-based triboelectric nanogenerator (T-TENG) based on 2D materials, addressing both energy harvesting and storage. The proposed system extracts significant ambient mechanical energy from human body movements and stores it in a textile supercapacitor (T-Supercap). The integration of 2D materials (graphene and MoS2) in fabrication enhances the performance of T-TENG significantly, as demonstrated by a record-high open-circuit voltage of 1068 V and a power density of 14.64 W/m2 under a force of 22 N. The developed T-TENG in this study effectively powers 200+ LEDs and a miniature watch while also charging the T-Supercap with 4-5 N force for efficient miniature electronics operation. Integrated as a step counter within a sock, the T-TENG serves as a self-powered step counter sensor. This work establishes a promising platform for wearable electronic textiles, contributing significantly to the advancement of sustainable and autonomous self-powered wearable technologies

Ultraflexible and robust graphene supercapacitors printed on textiles for wearable electronics applications

Printed graphene supercapacitors have the potential to empower tomorrow’s wearable electronics. We report a solid-state flexible supercapacitor device printed on textiles using graphene oxide ink and a screen-printing technique. After printing, graphene oxide was reduced in situ via a rapid electrochemical method avoiding the use of any reducing reagents that may damage the textile substrates. The printed electrodes exhibited excellent mechanical stability due to the strong interaction between the ink and textile substrate. The unique hierarchical porous structure of the electrodes facilitated ionic diffusion and maximised the surface area available for the electrolyte/ active material interface. The obtained device showed outstanding cyclic stability over 10 000 cycles and maintained excellent mechanical flexibility, which is necessary for wearable applications. The simple printing technique is readily scalable and avoids the problems associated with fabricating supercapacitor devices made of conductive yarn, as previously reported in the literature

Graphene-based high-performance pseudo-ductile glass-carbon/epoxy composites

High-performance fibre-reinforced polymer (FRP) composites offer outstanding specific strength and stiffness. However, their inherent brittleness can result in sudden and catastrophic failure without adequate warning, making them unsuitable for many applications. To overcome this limitation, we developed graphene-based glass-carbon FRP hybrid composites with excellent pseudo-ductile properties. Our method involves coating glass and carbon fibre fabrics with graphene-based materials using a scalable pad-dry-cure technique, followed by epoxy matrix reinforcement via vacuum-assisted resin infusion (VARI). Tensile and flexural tests reveal remarkable pseudo-ductile behaviour, with 1 wt% GNP-coated composites showing approximately ∼ 17.05 % higher Young's modulus, ∼18.52 % higher ultimate failure stress, and ∼ 31.73 % higher strain% compared to glass-carbon/epoxy hybrids. By enabling the manufacture of high-performance pseudo-ductile composites at scale using a cost-effective manufacturing method, these composites hold significant potential for next-generation applications

Контролируемые прочностные показатели для различных видов мебели

Методические указания по курсам «Расчет конструкций изделий из древесины и испытания мебели», «Технология изделий из древесины» для выполнения практических и лабораторных работ обучающимися по направлениям 35.03.02, 35.04.02 «Технология лесозаготовительных и деревоперерабатывающих производств», профиль «Технология деревообработки

All Inkjet-Printed Graphene-Silver Composite Ink on Textiles for Highly Conductive Wearable Electronics Applications

© 2019, The Author(s). Inkjet-printed wearable electronic textiles (e-textiles) are considered to be very promising due to excellent processing and environmental benefits offered by digital fabrication technique. Inkjet-printing of conductive metallic inks such as silver (Ag) nanoparticles (NPs) are well-established and that of graphene-based inks is of great interest due to multi-functional properties of graphene. However, poor ink stability at higher graphene concentration and the cost associated with the higher Ag loading in metal inks have limited their wider use. Moreover, graphene-based e-textiles reported so far are mainly based on graphene derivatives such as graphene oxide (GO) or reduced graphene oxide (rGO), which suffers from poor electrical conductivity. Here we report inkjet printing of highly conductive and cost-effective graphene-Ag composite ink for wearable e-textiles applications. The composite inks were formulated, characterised and inkjet-printed onto PEL paper first and then sintered at 150 °C for 1 hr. The sheet resistance of the printed patterns is found to be in the range of ~0.08–4.74 Ω/sq depending on the number of print layers and the graphene-Ag ratio in the formulation. The optimised composite ink was then successfully printed onto surface pre-treated (by inkjet printing) cotton fabrics in order to produce all-inkjet-printed highly conductive and cost-effective electronic textiles

An Efficient Method for Projection-Based Image Deblurring

Abstract Previously lot of problems are encountered in image processing -image deblurring. From the origination of the image deblurring to its broad applications in enormous number of areas today, the deblurring approaches have evolved with time and forked into many different and fascinating branches. In this paper, we propose a method for reducing out-of-focus blur caused by projector projection. We estimate the Point-Spread-Function (PSF) in the image projected onto the screen by using a camera that captures the projector screen. According to the estimated PSF, the original image is pre-corrected, so that the projected image can be deblurred. Proposed system can successfully reduce the effects of out-offocus projection blur, even though the screen image includes spatially varying blur without projecting the feature image

Engineering Graphene Flakes for Wearable Textile Sensors via Highly Scalable and Ultrafast Yarn Dyeing Technique

© 2019 American Chemical Society. Multifunctional wearable e-textiles have been a focus of much attention due to their great potential for healthcare, sportswear, fitness, space, and military applications. Among them, electroconductive textile yarn shows great promise for use as next-generation flexible sensors without compromising the properties and comfort of usual textiles. However, the current manufacturing process of metal-based electroconductive textile yarn is expensive, unscalable, and environmentally unfriendly. Here we report a highly scalable and ultrafast production of graphene-based flexible, washable, and bendable wearable textile sensors. We engineer graphene flakes and their dispersions in order to select the best formulation for wearable textile application. We then use a high-speed yarn dyeing technique to dye (coat) textile yarn with graphene-based inks. Such graphene-based yarns are then integrated into a knitted structure as a flexible sensor and could send data wirelessly to a device via a self-powered RFID or a low-powered Bluetooth. The graphene textile sensor thus produced shows excellent temperature sensitivity, very good washability, and extremely high flexibility. Such a process could potentially be scaled up in a high-speed industrial setup to produce tonnes (∼1000 kg/h) of electroconductive textile yarns for next-generation wearable electronics applications

Scalable Production of Graphene-Based Wearable E-Textiles

© 2017 American Chemical Society. Graphene-based wearable e-textiles are considered to be promising due to their advantages over traditional metal-based technology. However, the manufacturing process is complex and currently not suitable for industrial scale application. Here we report a simple, scalable, and cost-effective method of producing graphene-based wearable e-textiles through the chemical reduction of graphene oxide (GO) to make stable reduced graphene oxide (rGO) dispersion which can then be applied to the textile fabric using a simple pad-dry technique. This application method allows the potential manufacture of conductive graphene e-textiles at commercial production rates of ∼150 m/min. The graphene e-textile materials produced are durable and washable with acceptable softness/hand feel. The rGO coating enhanced the tensile strength of cotton fabric and also the flexibility due to the increase in strain% at maximum load. We demonstrate the potential application of these graphene e-textiles for wearable electronics with activity monitoring sensor. This could potentially lead to a multifunctional single graphene e-textile garment that can act both as sensors and flexible heating elements powered by the energy stored in graphene textile supercapacitors

Smart electronic textile‐based wearable supercapacitors

Abstract: Electronic textiles (e‐textiles) have drawn significant attention from the scientific and engineering community as lightweight and comfortable next‐generation wearable devices due to their ability to interface with the human body, and continuously monitor, collect, and communicate various physiological parameters. However, one of the major challenges for the commercialization and further growth of e‐textiles is the lack of compatible power supply units. Thin and flexible supercapacitors (SCs), among various energy storage systems, are gaining consideration due to their salient features including excellent lifetime, lightweight, and high‐power density. Textile‐based SCs are thus an exciting energy storage solution to power smart gadgets integrated into clothing. Here, materials, fabrications, and characterization strategies for textile‐based SCs are reviewed. The recent progress of textile‐based SCs is then summarized in terms of their electrochemical performances, followed by the discussion on key parameters for their wearable electronics applications, including washability, flexibility, and scalability. Finally, the perspectives on their research and technological prospects to facilitate an essential step towards moving from laboratory‐based flexible and wearable SCs to industrial‐scale mass production are presented