fig6

Figure 6. (A) (i) Schematic of multimaterials thermal drawing; (ii) Optical photograph of the cross section of the as-drawn fiber; (iii) SEM image of the fiber cross section after Se-nanowire formation; ⅳ) Ratio I_ph/I_dark versus power for the same fibers; ⅴ) Schematic of the fluorescence imaging system. Top: photograph of the “EPFL” logo filled with dye Rhodamine B dissolved in ethanol; bottom: fluorescent image obtained with the hybrid fiber device^[39]; Copyright 2017, Wiley-VCH. (B) (i) Fabrication technique based on iterative size reduction to produce ordered, indefinitely long nanowire and nanotube arrays; (ii) A polymer-embedded nanowire array rolled around a pencil; (iii) Cross-sectional SEM micrographs from both sides of a 10-m-long polymer fibre that contains hundreds of nanowires; (iv) The photoconductance from a selenium nanowire in the dark and on white-light illumination^[70]; Copyright 2011, Nature Publishing Group. (C) (i) Schematic illustration of the Se nanobelts photodetectors on transparent and flexible PET film; (ii) Optical transmittance spectra of Se nanobelts photodetector, the inset shows a picture of the photodetectors on PET film; (iii) Photoresponse of the photodetector a PET substrate with different bending angles, the inset shows a picture of the bending setup^[94]; Copyright 2012, Royal society of chemistry. (D) (i) 3D illustration of the Se-PENG device; (ii) Optical images of the device in the original state, being stretched and twisted, respectively; (iii) The output current of the Se-PENG attached on the human fingers and bent with different angles; (iv) and (v) The real-time artery pulse signal monitored by the Se-PENG^[85]; Copyright 2015, Elsevier.