With the increasing demand for composites of multifunctional and integrated performance, graphene-based nanocomposites have been attracting increasing attention in biomedical applications because of their outstanding physicochemical properties and biocompatibility. High product yields and dispersion of graphene in the preparation process of graphene-based nanocomposites have long been a challenge. Further, the mechanical properties and biosafety of final nanocomposites are very important for real usage in biomedical applications. Here, we presented a novel high-throughput method of graphene on mechanical exfoliation in a natural honey medium, and a yield of ∼91% of graphene nanoflakes can be easily achieved with 97.76% of single-layer graphenes. The mechanically exfoliated graphene (MEG) can be well-dispersed in the poly(vinyl alcohol) (PVA) matrix. The PVA/MEG nanocomposite fibers are obtained by gel spinning and stretched 20 times. As a candidate for monofilament sutures, the PVA/MEG nanocomposite fibers with 0.3 wt % of MEG have an ultrahigh ultimate tensile strength of 2.1 GPa, which is far higher than that of the neat PVA fiber (0.75 GPa). In addition, the PVA/MEG nanocomposite fibers also have antibacterial property, low cytotoxicity, and other properties. On the basis of the above-mentioned properties, the effects of a common surgical suture and PVA/MEG nanocomposite fibers on wound healing are evaluated. As a result, the wounds treated with PVA/MEG nanocomposite fibers with 0.3 wt % of MEG show the best healing after 5 days of surgery. It is possible that this novel surgical suture will be available in the market relying on the gentle, inexpensive method of obtaining nonoxidized graphene and the simple process of obtaining nanocomposite fibers.

Wearable conductive fabrics are an essential part of flexible electronics, which can be used as portable devices for human thermal management, healthcare, and motion detection. However, obtaining low-cost and scalable production of these types of conductive fabrics with high conductivity, low-voltage-activating electrothermal response, and satisfactory washability still has critical challenges. Herein, high-conductive graphene ink-decorated cotton fabrics (CFs) are fabricated via a facial double-side screen-printing technique for flexible wearable heaters and strain sensors. The porous and rough CFs with spatially distributed graphene inks create efficient pathways for electron movement, and the outmost water-soluble polyurethane could dramatically promote the washability, cycling stability, and environmental resistance properties of conductive fabrics. Interestingly, the as-obtained graphene conductive textiles demonstrate high conductivity (1.18 × 104 S/m), which are applied to flexible wearable heaters, showcasing a high steady-state temperature (52.6 °C) at a low voltage of 3 V, excellent washability, cycling stability, and environmental resistance properties. Additionally, the fabricated conductive fabrics can also be applied to wearable strain sensors, which exhibit high sensitivity, excellent recovery, and stability in a refined strain range for responding to human motions. Consequently, the designed graphene conductive fabrics provide a promising strategy to realize low-cost and scalable next-generation wearable electronic textiles.

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Rational engineering and simplified production of printable graphene inks are essential for building high-energy and flexible graphene micro-supercapacitors (MSCs). However, few graphene-based MSCs show impressive areal capacitance and energy density, especially based on additive-manufacturing, cost-effective, and printable inks. Herein, a newstyle and solution-processable graphene composite ink is ingeniously formulated for scalable screen printing MSCs. More importantly, the asformulated inks consist of interwoven two-dimensional graphene and activated carbon nanofillers, which are delaminated by one-step sandmilling turbulent flow exfoliation. Notably, embedding the activated carbon nanoplatelets into graphene layers drastically boosts the electrochemical performance of screen-printed micro-supercapacitors (denoted as Gr/AC-MSCs), such as an outstanding areal capacitance of 12.5 mF cm −2 (about 20 times than pure graphene). The maximum energy density, maximum power density, and exceptional cyclability are 1.07 μW h cm −2 , 0.004 mW cm −2 , and 88.1% after 5000 cycles, respectively. As such, the as-printed MSCs on paper display high resolution and pronounced energy-storage performance. Furthermore, the packaged and optimized Gr/AC-MSCs showcase remarkable mechanical flexibility even under highly folded and excellent water resistance, maintaining 91.8% capacitance retention after being washed for 90 min. The versatile methodology highlights the promise of graphene and analogous 2D nanosheet functional inks for scalable fabrication of flexible energy-storage devices.

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