Flexible Light Emitting Diodes are versatile lighting solutions that offer bendable and adaptable illumination possibilities. A soft, flexible white luminescent film (1 mm) shows promise for foldable electroluminescent devices and applications. This film was fabricated using ZnS:Ag and Mn. Under different excitation wavelengths, the phosphors emit blue light due to Ag⁺ luminescence centers and red light from the d-d transition of Mn²⁺. The blue emission is greatly suppressed at high Mn²⁺ doping levels, requiring reduced Ag⁺ doping in co-doped ZnS:Ag,Mn compared to solo-doped ZnS:Ag samples. By adjusting Ag⁺ and Mn²⁺ concentrations, the ZnS:Ag(1%),Mn(0.2%) phosphors show a proper intensity ratio of blue and red emissions, making them a promising candidate for future white light applications.

In the face of pandemic infectious diseases and increasing aging trends, traditional public health systems lack the capacity for real-time monitoring, immediate clinical detection, continuous vital sign monitoring, and the implementation of long-cycle treatment protocols, among other deficiencies. On the basis of the rapid development of wearable electronic devices, the Internet of Things, and artificial intelligence, the future healthcare model will transform from a therapeutic, centralized, passive, and even one-size-fits-all treatment to a new paradigm of proactive, preventive, personalized, customized, and intelligent way. The development of wearable electronics has facilitated the evolution of healthcare from healthcare to biological monitoring, enabling continuous monitoring of critical biomarkers for diagnostic treatment, physiological health monitoring, and assessment. Electronic textiles (e-textiles) are among the rapidly developing wearable electronics in recent years. They have revolutionized the functionality of traditional textiles by incorporating smart attributes, enabling unique and multifunctional applications. Significantly, e-textiles have made notable advancements in the field of personalized healthcare. The article introduces several common e-textiles and their applications in personalized medicines, which also gives a forward-looking outlook on their future growth in infectious diseases, real-time health preventive monitoring, auxiliary therapy, and rehabilitation training.

Inorganic p-type Sb₂Te₃ flexible thin films (f-TFs) with eco-friendly and high thermoelectric performance have attracted wide research interest and potential for commercial applications. This study employs a facile in-situ reaction method to prepare flexible Sb₂Te₃ thin films by rationally adjusting the synthesized temperature. The prepared thin films show good crystallinity, which enhances the electrical conductivity of ~1,440 S·cm^-1 due to the weakened carrier scattering. Simultaneously, the optimized carrier concentration, through adjusting the synthesis temperature, causes the intermediate Seebeck coefficient. Consequently, a high-power factor (16.0 μW·cm^-1·K^-2 at 300 K) is achieved for Sb₂Te₃ f-TFs prepared at 623 K. Besides, the f-TFs also exhibit good flexibility due to the slight change in resistance after bending. This study specifies that the in-situ reaction method is an effective route to prepare Sb₂Te₃ f-TFs with high thermoelectric performance.

Nerve stimulation technology utilizing electricity, magnetism, light, and ultrasound has found extensive applications in biotechnology and medical fields. Neurostimulation devices serve as the crucial interface between biological tissue and the external environment, posing a bottleneck in the advancement of neurostimulation technology. Ensuring safety and stability is essential for their future applications. Traditional rigid devices often elicit significant immune responses due to the mechanical mismatch between their materials and biological tissues. Consequently, there is a growing demand for flexible nerve stimulation devices that offer enhanced treatment efficacy while minimizing irritation to the human body. This review provides a comprehensive summary of the historical development and recent advancements in flexible devices utilizing four neurostimulation techniques: electrical stimulation, magnetic stimulation, optic stimulation, and ultrasonic stimulation. It highlights their potential for high biocompatibility, low power consumption, wireless operation, and superior stability. The aim is to offer valuable insights and guidance for the future development and application of flexible neurostimulation devices.

Epidermal electrodes can be directly attached to the human skin for high-fidelity electrophysiological monitoring owing to their preponderance in thinness, lightweight, conformability, biocompatibility, self-adhesiveness, mechanical flexibility, gas-permeability, etc. These devices have attracted immense attention due to their emerging applications in personalized health care, human/brain-machine interfaces, and soft robotics. This Perspective focuses on the most recent significant progress in this area, especially materials, properties, and applications. Challenges and prospects are summarized to underscore the unexploited areas and future directions toward digital health and on-skin digitalization.

Sweating is an important physiological reaction and a clinical symptom in a variety of diseases. However, it remains underrated in clinical use. Gold standards to measure the sweat rate are neither continuous nor easily or lab-independently applicable. With the emergence of novel wearable devices, using the sweat rate as a digital biomarker shows promise for clinical monitoring and diagnostics. In this Commentary, we discuss the potential and importance of the sweat rate as a digital biomarker in clinical medicine beyond sports science.

Electrochemical glucose sensors that rely on two-dimensional (2D) oxides have attracted significant attention owing to the strong sensing activity of 2D oxides, but their practical application is hindered by the complexity and high cost of fabrication of electrodes and integrated devices. Herein, a convenient and effective fabrication route that includes printing a Ga-based liquid metal (LM) as a current collection electrode, followed by growing electrochemically active 2D oxides directly on the surface of Ga-based LMs under mild conditions, is developed for non-enzyme-based electrochemical sensors. Specifically, 2D annealed Cu-Oxide (ACO) is successfully grown on a printed Ga electrode through a galvanic replacement reaction, resulting in the formation of a mechanically and electrically well-matched interface between the active sensing materials and the current collection substrate. Benefitting from the high quantity of 2D ACO and good charge transfer at the interface, the as-prepared ACO electrode exhibits attractive glucose sensing performance, with a wide linear range (1 μM-10 mM) of effective detection, low detection limit down to 1 μM, and high sensitivity of 0.87 μA·mM^-1·cm^-2. Our study highlights the potential of using LMs in bio-sensing applications and provides a non-enzyme-based electrochemical biosensor platform for effective glucose detection in diets and clinical diagnostic settings.

Simultaneous monitoring of the body’s biochemical and biophysical signals via wearable devices can provide a comprehensive assessment of an individual’s health state. However, current multifunctional sensors for synchronous biochemical and biophysical sensing rely on discrete sensing units, posing a limitation in increased complexity in device assembly, signal processing, and system integration. In this study, we report a dual-mode and self-powered wearable sensor with ion and pressure-sensing capabilities by interfacing a hydrogel film with a solid ion-selective electrode. The hydrogel film can not only collect natural sweat from the skin but also offer a piezoionic response to pressure. We show that wrist pulse-induced pressure response can be incorporated into the noise of the response to sweat sodium ions, allowing for the simultaneous measurement of heart rate and sweat electrolytes. This work provides an example of simplifying the development of wearable multimode sensors through the rational design of classic electrochemical sensors.

Cryosurgery and cryopreservation, as two important categories in cryobiology, have been impeded by the poor thermal conductivity of biological tissues or specimens. To improve this, diverse adjuvants, e.g., carbon-based materials, metallic nanoparticles, metallic oxide nanoparticles, etc., have been exploited to improve the heat transfer in heat-targeted regions to increase the tumor elimination efficiency as well as the post-thaw viability of cryopreserved specimens. Nevertheless, these materials suffer poor thermal conductivities, controversial biosafety problems, and high expense. Gallium and its alloys, as a class of room-temperature liquid metals (LMs), have been widely studied in the past decade for their low melting point, minor toxicity, outstanding transformability, and conductivity. Integrated with these superior properties, they have been widely applied in multiple fields, such as thermal management, flexible electronics, and soft robotics. Recently, our laboratory has been devoted to fusing LMs with cryobiology and has made a series of progress. In this article, we will first briefly introduce preparation pathways to LM-based functional nanomaterials and composites. Then, how these materials realize improvement in biological heat transfer will be presented, followed by a discussion about the biosafety of these materials, which is an essential concern for the cryobiological field. Recent studies employing LMs in advanced cryosurgery and cryopreservation will also be highlighted. The present challenges and prospects of LMs towards further development in cryobiology will be put forward to point out the possible research direction.

Flexible and skin-wearable triboelectric nanogenerators (TENGs) have emerged as promising candidates for self-powered tactile and pressure sensors and mechanical energy harvesters due to their compatible design and ability to operate at low frequencies. Most research has focused on improving tribo-negative materials for flexible TENGs, given the limited options for tribo-positive materials. Achieving biocompatibility while maintaining the sensitivity and capability of energy harvesting is another critical issue for wearable sensors. Here, we report a TENG-based biocompatible and self-powered pressure sensor by simple fabrication of layer-by-layer deposition methods. The Laminated Flexible-TENG comprises polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) films embedded within a flexible and biocompatible polydimethylsiloxane (PDMS) matrix. A nanostructured PDMS surface obtained by oxygen plasma facilitated the sputter deposition of a layered indium tin oxide copper electrode and a tribo-positive PMMA thin layer on top. The addition of the indium tin oxide layer to copper significantly improved the quality and performance of the indium tin oxide-copper electrode. Self-powered Laminated Flexible-TENGs demonstrated impressive pressure-sensing capabilities, featuring dual sensitivity of 7.287 V/kPa for low pressure and 0.663 V/kPa for higher pressure. Moreover, the PDMS-encapsulated TENG sensor effectively traced the physiological motions, such as wrist and finger bending, and efficiently harnessed the waste energy from everyday physical activities, such as walking and jogging. The maximum peak-to-peak voltages of 18.3 and 57.4 V were recorded during these motions. Encapsulated TENGs have broad potential in wearable technology, including healthcare, human-machine interfaces, and energizing microelectronics.