In this work, we report a class of wearable, stitchable, and sensitive carbon nanofiber (CNF)-polydimethylsiloxane (PDMS) composite-based piezoresistive sensors realized by carbonizing electrospun polyacrylonitrile (PAN) nanofibers and subsequently embedding in PDMS elastomeric thin films. Electro-mechanical tactile sensing characterization of the resulting piezoresistive strain sensors revealed a

To address the resource-competing issue between high sensitivity and wide working range for a stand-alone sensor, development of capacitive sensors with an adjustable gap between two electrodes has been of growing interest. While several approaches have been developed to fabricate tunable capacitive sensors, it remains challenging to achieve, simultaneously, a broad range of tunable sensitivity and

Mechanical stability of flexible batteries is the guarantee for delivering stable performance. The interacting external and inner forces determine it.

Diabetes is a chronic metabolic disease characterized by high glucose concentration in blood. Conventional management of diabetes requires skin pricking and subcutaneous injection, causing physical pain and physiological issues to diabetic individuals. Hydrogels possess unique advantages such as lightweight, stretchability, biocompatibility, and biodegradability, offering the opportunities to be integrated

Liquid metal represents a highly conductive and inherently deformable conductor for the development of stretchable electronics. The widespread implementations of liquid metal towards functional sensors and circuits are currently hindered by the lack of a facile and scalable patterning approach. In this study, we report a fully solution-based process to generate patterned features of the liquid metal

The simple structure of flexible piezoelectric polymers implies promise innumerous applications, such as transparent loudspeakers. In this study, we fabricated and characterized a prototype loudspeaker device. The loudspeaker was fabricated using a straightforward method of sandwiching a film of copolymer blend between a pair of flexible ITO substrates, which served as top and bottom electrodes. The

Hydrogels are a widely used ionic conductor in on-skin electronic and iontronic devices. However, hydrogels dehydrate in the open air and freeze at low temperatures, limiting their real applications when they are attached on skin or exposed to low temperatures. Polymer-ionic liquid gels can overcome these two obstacles, but synthetic ionic liquids are expensive and toxic. In this work, we present an

The organic magnetoelectric complexes are beneficial for the development on flexible magnetoelectric devices in the future. In this work, we fabricated all organic multiferroic ferromagnetic/ferroelectric complexes to study magnetoelectric coupling at room temperature. Under the stimulus of external magnetic field, the localization of charge inside organic ferromagnets will be enhanced to affect spin–dipole

Ultralong organic phosphorescence (UOP) crystals have attracted increased attention due to the distinct photophysical property of a long-lived lifetime. However, organic crystals are generally brittle, leading to a serious problem for their application in flexible technology. Herein, we report three types of elastic organic crystals (EOCs) with ultralong phosphorescence via introducing halogen atoms

The internal availability of silent speech serves as a translator for people with aphasia and keeps human–machine/human interactions working under various disturbances. This paper develops a silent speech strategy to achieve all-weather, natural interactions. The strategy requires few usage specialized skills like sign language but accurately transfers high-capacity information in complicated and changeable

Glioblastoma is a highly aggressive brain tumor, very invasive and thus difficult to eradicate with standard oncology therapies. Bioelectric treatments based on pulsed electric fields have proven to be a successful method to treat cancerous tissues. However, they rely on stiff electrodes, which cause acute and chronic injuries, especially in soft tissues like the brain. Here we demonstrate the feasibility

Transfer printing of high mobility inorganic nanostructures, using an elastomeric transfer stamp, is a potential route for high-performance printed electronics. Using this method to transfer nanostructures with high yield, uniformity and excellent registration over large area remain a challenge. Herein, we present the ‘direct roll transfer’ as a single-step process, i.e., without using any elastomeric

In recent years, flexible stress sensors capable of monitoring diverse body movements and physiological signals have been attracting great attention in the fields of healthcare systems, human–machine interfaces, and wearable electronics. Inspired by the structure of natural eggshell inner membrane (ESIM), we developed a pressure sensor based on MXene (Ti3C2Tx)/Ag NWs (silver nanowires) composite electrodes

In this work, carbon nanotubes pillared grew on exfoliated graphite by the microwave-assisted method is utilized as thermally conductive fillers (CPEG) in polyimide (PI) to fabricate CPEG/PI thermally conductive composites with the combining ways of “in-situ polymerization, electrospinning, lay-up, and hot-pressing”. The prepared CPEG/PI composites realized the maximum thermal conductivity (λ, 1.92 W m−1

This study illustrates an innovative way to fabricate inkjet-printed tracks by sequential printing of Zn nanoparticle ink and curing ink for low temperature in situ chemical sintering. Employing chemical curing in place of standard sintering methods leads to the advantages of using flexible substrates that may not withstand the high thermal budgets of the standard methods. A general formulation engineering

Wearable electronic devices are being developed because of their wide potential applications and user convenience. Among them, wearable organic light emitting diodes (OLEDs) play an important role in visualizing the data signal processed in wearable electronics to humans. In this study, textile-based OLEDs were fabricated and their practical utility was demonstrated. The textile-based OLEDs exhibited

Diversified regulation of electrons have received much attention to realize a multi-functional transistor, and it is crucial to have a considerable control over the charge carriers in transistors. Ionic gel, as the dielectric material in transistors, facilitates a large capacitance, and high induced-carrier concentrations. This review presents the recent progress in ionic-gated transistors (IGTs) that

With the trend of integration, miniaturization, and increasing power density of stretchable electronic devices, real-time thermal dissipation is becoming crucial. Seeking materials and/or structures with advanced thermal management for stretchable electronics becomes an urgent issue. For passive thermal management, the traditional thermal interfacial materials (TIMs) with flexibility cannot meet the

Few works had systematically investigated the relationship between the rupture stress of the oxide shell and the diameter of liquid metal nanoparticles (LMNPs). Here, we fabricated a series of elastomer/LMNPs composites, which were based on various polyurethanes with different shore hardness and LMNPs with different diameters, to systematically study the rupture stress of LMNPs. We established a reliable

Wearable devices have found numerous applications in healthcare ranging from physiological diseases, such as cardiovascular diseases, hypertension and muscle disorders to neurocognitive disorders, such as Parkinson’s disease, Alzheimer’s disease and other psychological diseases. Different types of wearables are used for this purpose, for example, skin-based wearables including tattoo-based wearables

Short-wavelength infrared (SWIR) sensors have attracted keen attention due to the increasing necessity in a variety of scientific and industrial applications, including biomedical and information technology fields. Because conventional SWIR sensors are made of inorganic materials with rigid and brittle characteristics, organic materials with a discrete SWIR absorption are required for flexible SWIR

Tandem quantum-dot light-emitting diodes (QLEDs) with multiple QLED elements vertically connected by the intermediate electrodes offer the advantages of high brightness and long lifetime. However, it is challenging to individually address each QLED element in conventional tandem structures. To address this challenge, here, transparent QLEDs built on flexible plastic substrates are developed as the

Paper, as a foldable, pollution-free, and low-cost material, has become a suitable support substrate for producing flexible thermoelectric (TE) generators to realize waste heat recycling and the application of human-powered electronic devices. We propose a facile fabrication method to modify cellulose paper with inorganic TE powders via vacuum filtration, making a modified paper that possesses good

State-of-the-art tissue analogues used in high-fidelity, hands-on medical simulation modules can deliver lifelike appearance and feel but lack the capability to provide quantified, real-time assessment of practitioner performance. The monolithic fabrication of hybrid printed/textile piezoresistive strain sensors in a realistic Y/V plasty suture training pad is demonstrated. A class of 3D-printable

Harvesting body heat using thermoelectricity provides a promising path to realizing self-powered, wearable electronics that can achieve continuous, long-term, uninterrupted health monitoring. This paper reports a flexible thermoelectric generator (TEG) that provides efficient conversion of body heat to electrical energy. The device relies on a low thermal conductivity aerogel–silicone composite that

Flexible sensors in wearable electronics have become increasingly multifunctional due to the development of materials synthesis and structure design. In particular, structural design can not only add capabilities to sensors fabricated from existing available and normal materials, but also offer opportunities for the fabrication of sensors with certain desired functions. Here, we designed a series of

Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect, due to its high carrier mobility, low sheet carrier density, and low-temperature dependence. However, the cost of graphene in comparison to conventional materials has meant that its uptake in electronic manufacturing has been slow. To lower technological barriers and bring more widespread adoption of graphene

Origami, an ancient form of papercraft, provides a way to develop functional structures for engineering applications. In this paper, we report an approach to design and manufacture a stretchable circuit board (SCB) with origami structures. The benefits of developable, flat-foldable, and rigid-foldable origami-based structures as SCBs are discussed, and a representative structure, Miura fold (or Miura-ori)

Energy-harvesting from low-temperature environmental heat via thermoelectric generators (TEG) is a versatile and maintenance-free solution for large-scale waste heat recovery and supplying renewable energy to a growing number of devices in the Internet of Things (IoT) that require an independent wireless power supply. A prerequisite for market competitiveness, however, is the cost-effective and scalable

We show flexible bolometer devices produced entirely using digital inkjet printing on polymer substrates. The bolometers consist of a silver interdigital electrode thermistor covered with a methylammonium lead trihalide perovskite absorber layer which shows good absorber characteristics at visible wavelengths. Both the standalone thermistor and the complete bolometer devices show polymer PTC thermistor-like

A clothing-type wearable display can be utilized in fashion, bio-healthcare, and safety industries as well as smart textiles for the internet of things (IoTs) and wearable devices. In response to this trend, we demonstrate a textile display that can endure the active movements of a human body. It can be applied to any kind of textile, and is durable against conditions such as rain, sweat, and washing

Soft structural textiles, or softgoods, are used within the space industry for inflatable habitats, parachutes and decelerator systems. Evaluating the safety and structural integrity of these systems occurs through structural health monitoring systems (SHM), which integrate non-invasive/non-destructive testing methods to detect, diagnose, and locate damage. Strain/load monitoring of these systems is

The rapid development of wearable, highly integrated, and flexible electronics has stimulated great demand for on-chip and miniaturized energy storage devices. By virtue of their high power density and long cycle life, micro-supercapacitors (MSCs), especially those with interdigital structures, have attracted considerable attention. In recent years, tremendous theoretical and experimental explorations

Flexible, large-area, and stable perovskite photodetectors have drawn increasing widespread research attention for next-generation wearable and portable optoelectronic devices. However, high mechanical durability coupled with large device area and enhanced environmental stability has not been demonstrated yet to attain practical viability. Herein, a highly bendable, stable, and large-area (3 cm2) flexible

The era of artificial intelligence and internet of things is rapidly developed by recent advances in wearable electronics. Gait reveals sensory information in daily life containing personal information, regarding identification and healthcare. Current wearable electronics of gait analysis are mainly limited by high fabrication cost, operation energy consumption, or inferior analysis methods, which

Flexible sensors are required to be lightweight, compatible with the skin, sufficiently sensitive, and easily integrated to extract various kinds of body vital signs during continuous healthcare monitoring in daily life. For this, a simple and low-cost flexible temperature and force sensor that uses only two carbon fiber beams as the sensing layer is reported in this work. This simple, flexible sensor

We present a facile method to prepare flexible, transparent, biodegradable, and fast resistive heaters by applying silver (Ag) nanowires onto fractal-like leaf skeletons. The fractal-like structure of the leaf skeleton maximizes its surface area, improving the transfer of heat to its surroundings and thus making the heater fast, without compromising transparency. Ag ion layer on the leaf skeleton helps

Polymer thermoelectric (TE) composites have witnessed explosive developments in recent years, arising from their promising prospect for lightweight flexible electronics and capability of harvesting waste-heat. In sharp contrast with intrinsically conducting polymers (CPs), the insulating thermoplastics have seldom been employed as the matrices for flexible TE composites despite their advantages of

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The future of printed electronics involves advancements not only related to full system integration, but also lean process manufacturing. A critical aspect of this progress is developed in this study, which evaluates a highly flexible screen printed through-hole-via using silver microparticle inks, for applications in energy harvesting and storage modules. The printed vias’ fabrication and durability

Heat sensors form an important class of devices that are used across multiple fields and sectors. For applications such as electronic skin and health monitoring, it is particularly advantageous if the output electronic signals are not only high, stable, and reproducible, but also self-generated to minimize power consumption. Here, we present an ultrasensitive heat sensing concept that fulfills these

A curved image sensor on plastic foil has been developed for cone beam computed tomography (CBCT) X-ray imaging. The image sensor of about 6 × 8 cm2 size has been built on a thin polyimide foil with an indium gallium zinc oxide (IGZO) backplane and an organic photodetectors (OPD) frontplane. A flexible cesium iodide (CsI) scintillator has been attached to the optical sensor with 480 × 640 pixels of

Rollable photonic devices that can adapt to freeform surfaces with reduced dimensions while maintaining their original functionalities are highly desirable. Among photonic devices, metamaterials with hyperbolic dispersion in momentum space, defined as hyperbolic metamaterial (HMM), possess a large photonic density of states that has been proven to boost light-matter interaction. However, these devices

Printable electronics is a promising manufacturing technology for the potential production of low-cost flexible electronic devices, ranging from displays to active wear. It is known that rapid printing of conductive ink on a flexible substrate is vulnerable to several sources of variation during the manufacturing process. However, this process is still not being subjected to a quality control method

Transparent and flexible thermoelectrics has been highly sought after for future wearable devices. However, the main stumbling block to prevent its widespread adoption is the lack of p-type transparent thermoelectrics and the stringent criteria of electrical and thermal properties matching appropriately between p-legs and n-legs. This work demonstrates the fabrication of p-type PEDOT:PSS films whose

Laser-induced graphitization (LIG) is a method of converting a carbon-rich precursor into a highly conductive graphite-like carbon by laser scribing. This method has shown great promise as a versatile and low-cost patterning technique. Here we show for the first time how an ink based on cellulose and lignin can be patterned using screen printing followed by laser graphitization. Screen printing is

The potential of the screen printing method for large-scale production of organic electrochemical transistors (OECTs), combining high production yield with low cost, is here demonstrated. Fully screen-printed OECTs of 1 mm2 area, based on poly(3,4-ethylenedioxythiophene) doped with poly(styrensulfonate) (PEDOT:PSS), have been manufactured on flexible polyethylene terephthalate (PET) substrates. The

Sensor platforms that exploit the fibrous textile threads as substrates offer great promise since they can be directly sewn, woven or stitched on to any clothing. They can also be placed directly in intimate contact with the skin. In this work, we present a thread-based sensing platform in the form of a multiplexed sensing patch for continuous simultaneous on-skin monitoring of sweat. The patch performs

Bioelectronic interfaces employing arrays of sensors and bioactuators are promising tools for the study, repair and engineering of cardiac tissues. They are typically constructed from rigid and brittle materials processed in a cleanroom environment. An outstanding technological challenge is the integration of soft materials enabling a closer match to the mechanical properties of biological cells and

With the advent of the internet of things, flexible wearable devices are gaining significant research interest, as they are unobtrusive, comfortable to wear and can support continuous observation of physiological signals, helping to monitor wellness or diagnose diseases. Amorphous Indium Gallium Zinc Oxide (a-IGZO) Thin Film Transistors (TFTs) fabricated on flexible substrates are an attractive option

The increasing demands to further electrify and digitalize our society set demands for a green electrical energy storage technology that can be scaled between very small, and heavily distributed electrical energy sources, to very large volumes. Such technology must be compatible with fast-throughput, large-volume and low-cost fabrication processes, such as using printing and coating techniques. Here

Conformable electrodes are essential for the development of flexible electronics or functional clothing, regardless of their application. Their reliable ability to transfer electric signals or serve as sensing elements in various conditions is vital for the advancement of wearables that will enhance our everyday life. In this research, we concentrate our efforts on the understanding of the influence

The general use of smartphones assigns additional relevance to QR codes as a privileged tool to the Internet of Things (IoT). Crucial for QR codes is the evolution to IoT-connected smart tags with enhanced storage capacity and secure accesses. Using the concept of super-modules (s-modules) built from adjacent spatial multiplexed modules with regular geometrical shapes, assisted by colour multiplexing

Manufacturing a flexible, light, large-area, and high-efficiency electromagnetic shielding materials in a straightforward and cost-effective manner presently remains a significant challenge. In this work, we propose a conductive network design and verify its electromagnetic interference (EMI) shielding effectiveness (SE) by simulation. Using the structure and parameters obtained by simulation, we prepare

This work demonstrates the application of electrospun single and bundled carbon nanofibers (CNFs) as piezoresistive sensing elements in flexible and ultralightweight sensors. Material, electrical, and nanomechanical characterizations were conducted on the CNFs to understand the effect of the critical synthesis parameter—the pyrolyzation temperature on the morphological, structural, and electrical properties

Thin-film electronics played an important role in flexible healthcare sensor applications. The common status of their constituent blocks are solid film and network structures. However, the solid film could only sustain bend in a narrow range due to cracks, and the network structure decreased the sensitivity of flexion sensors due to the strong interactions between nanowires. New materials and technologies

To achieve high detectivity in infrared detectors, it is critical to reduce the device noise. However, for non-crystalline semiconductors, an essential framework is missing to understand and predict the effects of disorder on the dark current. This report presents experimental and modeling studies on the noise current in exemplar organic bulk heterojunction photodiodes, with 10 donor–acceptor combinations

High-throughput manufacturing of oxide electronics will enable new applications ranging from large-area displays to flexible medical devices and low-cost solar panels. However, high-quality oxide films from solution-based precursors typically require 20 min or more of thermal annealing at high temperature (>250 °C) for each layer, severely limiting both the throughput and substrate choice. Here, we

The rapid advancement of electronic devices and fabrication technologies has further promoted the field of wearables and smart textiles. However, most of the current efforts in textile electronics focus on a single modality and cover a small area. Here, we have developed a tailored, electronic textile conformable suit (E-TeCS) to perform large-scale, multimodal physiological (temperature, heart rate