This study reports on a facile and widely applicable method of transferring chemical vapor deposited (CVD) graphene uniformly onto optically transparent and mechanically flexible substrates using commercially available, low-cost ultraviolet adhesive (UVA) and hot-press lamination (HPL). We report on the adhesion potential between the graphene and the substrate, and we compare these findings with those of the more commonly used cast polymer handler transfer processes. Graphene transferred with the two proposed methods showed lower surface energy and displayed a higher degree of adhesion (UVA: 4.40 ± 1.09 N/m, HPL: 0.60 ± 0.26 N/m) compared to equivalent CVD-graphene transferred using conventional poly(methyl methacrylate) (PMMA: 0.44 ± 0.06 N/m). The mechanical robustness of the transferred graphene was investigated by measuring the differential resistance as a function of bend angle and repeated bend-relax cycles across a range of bend radii. At a bend angle of 100° and a 2.5 mm bend radius, for both transfer techniques, the normalized resistance of graphene transferred on polyethylene terephthalate (PET) was around 80 times less than that of indium-tin oxide on PET. After 10(4) bend cycles, the resistance of the transferred graphene on PET using UVA and HPL was found to be, on average, around 25.5 and 8.1% higher than that of PMMA-transferred graphene, indicating that UVA- and HPL-transferred graphene are more strongly adhered compared to PMMA-transferred graphene. The robustness, in terms of maintained electrical performance upon mechanical fatigue, of the transferred graphene was around 60 times improved over ITO/PET upon many thousands of repeated bending stress cycles. On the basis of present production methods, the development of the next-generation of highly conformal, diverse form factor electronics, exploiting the emerging family of two-dimensional materials, necessitates the development of simple, low-cost, and mechanically robust transfer processes; the developed UVA and HPL approaches show significant potential and allow for large-area-compatible, near-room temperature transfer of graphene onto a diverse range of polymeric supports.

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In this study we report on the electron transport in flexible-transparent polymer supported chemically doped chemical vapour deposited (CVD) graphene.

The primary barrier to wider commercial adoption of graphene lies in reducing the sheet resistance of the transferred material without compromising its high broad-band optical transparency, ideally through the use of novel transfer techniques and doping strategies. Here, chemical vapour deposited graphene was uniformly transferred to polymer supports by thermal and ultraviolet (UV) approaches and the time-dependent evolution of the opto-electronic performance was assessed following exposure to three kinds of common dopants. Doping with FeCl 3 and SnCl 2 showed minor, and notably time unstable, enhancement in the σ opt /σ dc figure of merit, while AuCl 3-doping markedly reduced the sheet resistance by 91.5% to 0.29 kΩ/ sq for thermally transferred samples and by 34.4% to 0.62 kΩ/sq for UV-transferred samples, offering a means of realising viable transparent flexible conductors that near the indium tin oxide benchmark.

Hybrid integration of n-type oxide with p-type polymer transistors is an attractive approach for realizing high performance complementary circuits on flexible substrates. However, the stability of solution-processed oxide transistors is limiting the lifetime and reliability of such circuits. Oxygen vacancies are the main defect degrading metal oxide transistor performance when ambient oxygen adsorbs onto metal oxide films. Here, an effective surface passivation treatment based on negative oxygen ion exposure combined with UV light is demonstrated, that is able to significantly reduce surface oxygen vacancy concentration and improve the field effect mobility to values up to 41 cm 2 V −1 s −1 with high on-off current ratio of 10 8 . The treatment also reduces the threshold voltage shift after 2 days in air from 5 to 0.07 V. The improved stability of the oxide transistors also improves the lifetime of hybrid complementary circuits and stable operation of complementary, analog amplifiers is confirmed for 60 days in air. The suggested approach is facile and can be widely applicable for flexible electronics using low-temperature solution-processed metal oxide semiconductors.

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This study investigated the body image, body stress, eating attitude, and dietary quality in middle school girls. Questionnaires were administered to one hundred fifty seven middle school girls in Seoul area. The subjects were categorized into the five groups according to their body mass index (BMI); 1) severely under-weight (BMI < 16.5 kg/m ). 7.0%, 14.6%, 58.9%, 10.2%, and 10.2% of the subjects were classified as severely under-weight, under-weight, normal weight, overweight and obese groups, respectively. Regardless of the BMI, the subjects had disturbed body image, body stress, and poor eating attitude. The actual BMIs of the normal weight, overweight and obese subjects were significantly different from their desired BMI and perceived BMI, representing these subjects dissatisfied their body shape. Almost all subjects tried to lose their body weight even in the severely under-weight and under-weight groups. There were significant correlations of BMI with body image disturbance (p < 0.05), body stress (p < 0.01) and eating attitude (p < 0.05). These results indicated that middle school girls who have higher BMI seemed to have more body image distortion, body stress and risk of eating disorder. However, any significant difference in dietary quality among the five groups was not observed even though their dietary patterns were not balanced. As a conclusion, it is required that middle school girls should correct their distorted body image and body stress. Also, efforts to improve eating attitude, dietary pattern and nutritional status in the middle school girls are needed.