Acute postoperative pain is commonly treated with flurbiprofen (FBP), but conventional delivery methods are suboptimal. This study prepared a new non-burst release microneedles (MNs) using genipin cross-linked gelatin (cGel). By adding varying amounts of genipin to modulate the crosslinking degree of cGel, the drug release behavior of the drug-loaded MNs in the skin can be altered. The crosslinking parameters that meet therapeutic requirements are selected, thus providing rapid and long-lasting analgesic effects. cGel solutions were successfully cross-linked, altering matrix material microstructure, confirmed by scanning electron microscope imaging and fourier transform infrared spectroscopy. MNs demonstrated increasing mechanical strength with higher crosslinking. Drug release rates were rapid initially, then slowed, exhibiting a characteristic of decreased release rates with increasing degrees of crosslinking. In vivo, FBP/cGel MNs significantly reduced allodynia and hyperalgesia post-surgery, with the greatest effect observed at 2–3 h post-surgery, and can maintain analgesia for up to 6 h. Biosafety tests confirmed good biocompatibility. FBP/cGel MNs effectively penetrate the stratum corneum, safely delivering drugs with significant analgesic effects, excellent mechanical properties, and good biocompatibility, representing a promising strategy for managing acute postoperative pain.

Atrial fibrillation (AF) is a common and serious disease. Its diagnosis usually requires 12-lead electrocardiogram, which is heavy and inconvenient. At the same time, the venue for diagnosis is also limited to the hospital. With the development of the concept of intelligent medical, a wearable, portable, and reliable diagnostic method is needed to improve the patient’s comfort and alleviate the patient’s pain. Here, we reported a wearable atrial fibrillation prediction wristband (AFPW) which can provide long-term monitoring and AF diagnosis. AFPW uses polyvinylidene fluoride piezoelectric film as sensing material and hydrogel as skin bonding material, of which the structure and design have been optimized and improved. The hydrogel skin bonding layer has good stability and skin affinity, which can greatly improve the user experience. AFPW has enhanced signal, strong signal-to-noise ratio, and wireless transmission function. After a sample library of 385 normal people/patients is analyzed and tested by linear discriminant analysis, the diagnostic success rate of atrial fibrillation is 91%. All these excellent performances demonstrate the great application potential of AFPW in wearable device diagnosis and intelligent medical treatment.

Triboelectric nanogenerators (TENGs) have emerged as promising candidates for integrating with flexible electronics as self-powered systems owing to their intrinsic flexibility, biocompatibility, and miniaturization. In this study, an improved flexible TENG with a tile-nanostructured MXene/polymethyl methacrylate (PMMA) composite electrode (MP-TENG) is proposed for use in wireless human health monitor. The multifunctional tile-nanostructured MXene/PMMA film, which is self-assembled through vacuum filtration, exhibits good conductivity, excellent charge capacity, and high flexibility. Thus, the MXene/PMMA composite electrode can simultaneously function as a charge-generating, charge-trapping, and charge-collecting layer. Furthermore, the charge-trapping capacity of a tile nanostructure can be optimized on the basis of the PMMA concentration. At a mass fraction of 4% PMMA, the MP-TENG achieves the optimal output performance, with an output voltage of 37.8 V, an output current of 1.8 μA, and transferred charge of 14.1 nC. The output power is enhanced over twofold compared with the pure MXene-based TENG. Moreover, the MP-TENG has sufficient power capacity and durability to power small electronic devices. Finally, a wireless human motion monitor based on the MP-TENG is utilized to detect physiological signals in various kinematic motions. Consequently, the proposed performance-enhanced MP-TENG proves a considerable potential for use in health monitoring, telemedicine, and self-powered systems.

In cutaneous cosmetology surgery, local injection or coated anesthetics are generally used to provide analgesia at the treatment site to achieve painless operation. Due to the barrier of corneum, topical cream may cause uncertain dosage and delayed analgesia. Local injection has problems such as pain, infection, and misoperation. Therefore, it is necessary to develop a painless and rapid administration method for local anesthesia. Here, a lidocaine/hyaluronic acid bubble microneedle patch (Lido/HA bMNP) was prepared for rapid drug delivery and efficient analgesia. The bubble structure between microneedles (MNs) and the backing layer allowed the MNs to efficiently penetrate into the skin and remove from the backing layer under shear force to rapidly complete the administration. Drugs were quickly released with the dissolution of HA within 15 s, which immediately played an analgesic effect and lasted for 1 h. Lido/HA bMNP could deliver precise doses to the skin in an extremely short time, which had the advantages of convenient operation, high biosafety, rapid onset of analgesia, and reasonable pain relief time. This patch provided an alternative way for local anesthesia and it was a promising transdermal drug delivery method for the realization of high quality and efficiency “painless medical beauty”.

Recently, stretchable and wearable health monitoring equipment has greatly improved human’s daily life, which sets higher demands for portable power source in stretchability, sustainability, and biocompatibility. In this work, we proposed a stretchable triboelectric nanogenerator (TENG) based on stretchable poly (3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/porous carbon hybrid for oxyhemoglobin saturation (SpO2) monitoring. To combine advantages of carbon material for its high conductivity and organic electrode for its high stretchability, we spin-coated a solution of PEDOT:PSS/porous carbon onto a plasma-treated pre-stretched Ecoflex film to fabricate a stretchable electrode with rough surface. Due to its roughness and high potential difference with the dielectric material, the stretchable-electrode-based TENG exhibited better performance compared to the pristine TENG based on carbon or PEDOT:PSS material. The output voltage and current reached up to 51.5 V and 13.2 μA as the carbon concentration increased. More importantly, the performance further increased under large strain (100%) which is suitable for wearable systems. Finally, the device demonstrated its application potential for powering a flexible blood oxygen monitor. This simple and cost-effective method can enhance the stretchability and stability of organic/inorganic electrode-based TENG, which paves the development of high-performance stretchable TENG.

We developed a high-efficiency rotating triboelectric nanogenerator (R-TENG)-enhanced multilayered antibacterial polyimide (PI) nanofiber air filters for removing ultrafine particulate matter (PM) from ambient atmosphere. Compared to single-layered PI nanofiber filters, the multilayered nanofiber filter can completely remove all of the particles with diameters larger than 0.54 μm and shows enhanced removal efficiency for smaller PM particles. After connecting with aR-TENG, the removal efficiency of the filer for ultrafine particles is further enhanced. The highest removal efficiency for ultrafine particulate matter is 94.1% at the diameter of 53.3 nm and the average removal efficiency reached 89.9%. Despite an increase in the layer number, the thickness of each individual layer of the film decreased, and hence, the total pressure drop of the filter decreased instead of increasing. Moreover, the nanofiber film exhibited high antibacterial activity because of the addition of a small amount of silver nanoparticles. This technology with zero ozone release and low pressure drop is appropriate for cleaning air, haze treatment, and bacterial control.