a Micro and nano structure of central and peripheral nervous systems. b The principal micro- and nanofabrication technologies for TE applications.
Schematization of the fabrication process for 3D PCL pillared scaffolds using a hot press (on the left). a Silicon master production. b Micromolding melting step. c Micromolding pressing step. d Final structure obtained after solidification and detachment.
Nano-textured PCL film realized through a single-step plasma etching process. a The Silicon wafer acts as a support. b Embedding in cell culture medium. c Micro film peeling-off for “free-standing” use. d AFM images of the nano-structured PCL surface.
a SEM micrograph showing a flat glial cell monolayer suspended between adjacent nanostructured pillars. b Low magnification of neuronal somas and its processes. c Neuronal projections densely wrap the pillar nanopatterned sidewall.
SEM images of primary hippocampal cultures plated on nanopatterned PCL substrates. a Neurons resulted healthy, as indicated by the smooth surface of cell bodies (asterisk), b Dense network of neurites (arrows), which grew in tight adhesion with the substrate.
Confocal images of primary hippocampal cultures plated on nanopatterned PCL substrates at two magnifications (upper and lower rows). Neuronal class III -tubulin/synapsin I (a and a'), class III -tubulin/neural cell adhesion molecule (b and b') and class III -tubulin/phosphorylated neurofilament proteins (c and c').
SEM images of NIH/3T3 cells suspended on biocompatible PCL nanostructured micro pillars. a Fibroblasts within 24 h produced filopodia sensing the microstructured biopolymer, and b thicker pseudopodia-like processes appeared to use pillars as stepping-stones.
Number of scientific publications found in the Web of Science on topics of thin film transistors, thin film thermoelectric devices, thin film solar cells (SCs), thin film sensors, organic light emitting diodes (OLEDs), thin film shape memory materials, and thin film actuators, within the timespan of 2000 to 2015.
Number of scientific publications found in the Web of Science on “thin films”, and “solution-processed thin films” or “solution-based thin films” within the timespan of 2000 to 2015.
Schematic of an organic field-effect transistor (OFET). Heavily doped silicon is a traditional substrate, while silicon dioxide or other dielectrics serve as the gate insulator.
Structure of an organic non-volatile memory transistor with a polymer electret, based on semi-conjugated acceptor-based polyimides .
a Schematic of various layers of a thin film organic light emitting diode (OLED), and b the structure of the commercialized active-matrix OLED display (AMOLED) technology used in smartphones, etc.
Schematic of the structure of a thin film solar cell.
a Structure of a mesoporous perovskite SC, where FTO is used as the transparent conducting electrode, c-TiO2 as the ETL, and spiro-OMeTAD as the HTL. A planar structure is similar to (a), except that it does not have the mesoporous scaffold. b Structure of an inverted planar perovskite SC.
Structure of thin film chalcopyrite (CIGS) and kesterite (CZTSSe) solar cells.
Number of papers found in the Web of Science from 2000 to 2015 on solar cells that can be processed from solution, including polymer, dye-sensitized, quantum-dot, perovskite, CIGS and CZTS SCs.
Power generation and cooling modes of a thermoelectric device.
Typical structure of a two-terminal resistance-based (chemiresistive) thin film oxide sensor .
a Typical back-gate graphene-based FET on Si/SiO2 substrate used as gas sensor. b Typical solution-gate graphene-based FET on flexible polyethylene terephthalate (PET) substrate used as chemical and biological sensor in aqueous solutions .
Piezoelectric thin film device for generation of electricity from mechanical vibration. The silicon oxide is deposited via chemical vapor deposition, whereas the ZrO2 and PZT layers are processed and deposited in solution .
Schematic diagram of the fabrication process of a solution-processed thin film PZT energy harvesting device, using environmental micro-vibration as the source of mechanical energy. Using laser, a 2 μm spun-on PZT thin film deposited on transparent sapphire (a) was transferred onto a flexible PET plastic substrate (b), where electrodes and protective layer were deposited to complete the device .
Morpohology visualization usign high-resolution spectroscopic imaging with analytical transmission electron microscope for a sample P3HT:PCBM: a as casted, and b thermally annealed. c j-V curves for devices fabricated with same conditions as a, b. Adapted with permission from Ref. .
Representative P3HT:PC60BM, PTB7:PC60BM devices that illustrate the differences in the observed IS response for devices measured at 1 sun light intensity, at applied voltages close to Voc. Figure adapted with permission of Ref. .
Relationship between domain size, as calculated by absorption, XRD, defect densities, Voc of the devices for devices containing the system P3HT:PC60BM. Increased, defect states give rise to higher recombination processes reducing the Voc. Reproduced with permission from Ref. .
Diagrams representing adequate morphology for device operation in the nanoscale (a), microscale phase segregated phases (b) produced by degradation external agents.
Comparison Optical images of films after annealing at 130 °C for 80 h of a fullerene-attached diblock polymer, and b P3HT:PCBM. Adapted image reproduced with permission of Ref. .
TEM images of PTB7/PC71BM blend film prepared from chlorobenzene without (left), with (right) diiodooctane. The scale bar is 200 nm. Reproduced with permission from .
a Sketch representing the cross-linking process that provides reticulated networks. b Reactive functional units commonly used as crosslinkers.
Comparison of devices fabricated using different donor:acceptor systems in terms of their response to: a Capacitance-Temperature measurements, and b efficiency decay as the temperature at which the Capacitance is Maximum (TMAX). With permission from Ref. .
a Normalized open circuit voltage losses over illumination time for PCDTBT and P3HT solar cells. b Data measured with a solar simulator before and after burn-in for amorphous and crystalline materials. Reproduced from Ref.  with permission from The Royal Society of Chemistry.
Maps showing plasmon peak positions of ultrathin cross-sections of devices P3HT:PCBM devices: a fresh, and b aged. c Absorption spectra of fresh, aged films cast from CHCl3. d Evolution of defect density values (n), calculated fullerene content at the cathode interface extracted from capacitance-voltage measurements carried out in the dark of devices cast from CHCl3. Reproduced with permission from Ref. .
a j-V response of small molecule donor OPVs to understand the effect of active layer thickness. b Impedance spectra of devices shown in (a) measured at 1 sun illumination at Voc conditions. Reproduced from Ref.  with permission from The Royal Society of Chemistry.
Energy level diagrams representing the cathode equilibration of a bulk-heterojunction solar cell: a before contact equilibration, b after contact deposition. c Vfb results extracted from C-V measurements in the dark for devices processed under different conditions. Two sets of devices with different active layer thickness are included that show that the method is valid for different active layer thicknesses. Adapted from Ref. .
Sketch representing the method to monitor the presence of donor and acceptor molecules in close contact with a semitransparent electrode.
Morphology and composition characterizations of the Mo nanoscrews. a Representative SEM image of the Mo nanoscrews. b EDS spectrum of the Mo nanoscrews. Inset: magnified EDS spectrum showing the oxygen peak. c TEM image of a typical Mo nanoscrew. Inset: High-magnification TEM image of area enclosed by the square. d XRD spectrum of the Mo nanoscrews.
SERS activity characterizations of the Mo nanoscrews. a Raman spectra of MB molecules (10–4 M) adsorbed onto the Mo nanoscrews, Mo thin film, quartz, and stainless steel. The excitation wavelength was 633 nm. b SERS spectra of the Mo nanoscrews adsorbed with 10–4 M (green), 10–5 M (orange), and 10–6 M (light blue) of MB molecules. c Raman mapping image of the MB molecules (10–4 M) adsorbed onto the Mo nanoscrews. The mapping corresponded to the integrated intensity of the Raman band between 1550 and 1700 cm–1. The mapping area was over 100×100 μm2.
Raman mapping of the individual Mo nanoscrews modified with MB molecules (10–4 M). a-d SEM images and corresponding Raman maps of the Mo nanoscrews deposited onto the Mo film-coated glass substrate. e-h SEM images and corresponding Raman maps of the Mo nanoscrews deposited onto the ITO-coated glass substrate. The excitation wavelength was 633 nm. The mapping corresponded to the integrated intensity of the Raman band between 1550 and 1700 cm–1.
Characterizations of the hot-spots on an individual Mo nanoscrew. a AFM topography image of a typical Mo nanoscrew. Inset: Corresponding SEM image of the nanoscrew. b Optical near-field amplitude (3rd harmonics) at excitation of 633 nm recorded in the same area as that in a. c Calculated electric-field-magnitude enhancement contour of an individual Mo nanoscrew. The nanoscrew was excited by a p-polarized light at an incidence angle of 45º. The polarization of the incidence light had a component parallel to the length direction of the nanoscrew. The excitation wavelength was 633 nm. d Dark-field scattering spectrum of the Mo nanoscrew. Inset: Dark-field scattering image of the Mo nanoscrew.
Band assignments of the Raman spectrum from the MB molecules .
a Typical SEM image of CNT/GC, b CNT/rGO/GC, c AgNPs/CNT/rGO/GC, and d AgNPs/CNT/rGO/MoO2/Sal-His/GC electrodes. e EDX map analysis for AgNPs.
CVs curves of a bare GC, b rGO/GC, c CNT/GC, d AgNPs/GC, and e AgNPs/CNT /rGO/GC in 0.1 M PBS (pH 6.0) containing 0.1 M KCl and 3 mM [Fe(CN)6]3-/4- at a scan rate of 50 mV s-1.
Nyquist plots for various electrodes of a GC, b rGO/GC, c AgNPs/GC, d CNT/GC, and e AgNPs/CNT/rGO/GC in 0.1 M PBS containing 0.1 M KCl and 3 mM Fe(CN)6 3−/4− in the frequency range of 10 kHz-0.1 Hz.
a The CVs of the AgNPs/CNT/rGO/MoO2/Sal-His electrode in PBS (pH 2.0) at different scan rates: 10, 25, 50, 75, 100, 150, 200, 300, 400, and 500 mV s-1, respectively. b The variation of the anodic and cathodic peak current of the electrode versus potential scan rate.
a CVs curves of AgNPs/CNT/rGO/GC (1 and 2), and AgNPs/CNT/rGO/MoO2/Sal-His/GC (3 and 4) in the absence (1 and 3) and the presence (2 and 4) of 5mM of CySH in 0.1M PBS (pH 6.0) at a scan rate of 50 mV s-1. CVs curves of AgNPs/CNT/rGO/GC (1 and 5) and AgNPs/CNT/rGO/MoO2/Sal-His/GC (3 and 6) in the absence (1 and 3) and the presence (5 and 6) of 2 mM of iodate in 0.1 M PBS (pH 2.0) at a scan rate of 50 mV s-1. b CVs curves of the AgNPs/CNT/rGO/MoO2/Sal-His/GC at a scan rate of 50 mV s-1 in different concentrations of CySH (1'-3') of 5, 15, 30 mM and iodate (4'-6') of 0.5, 2, and 5 mM.
a CVs curves of the AgNPs/CNT/rGO/MoO2/Sal-His/GC in the presence of different CySH concentration (1-6) of 5, 15, 30, 60,100, 150 mM in 0.1M PBS (pH 6.0) at a scan rate of 50 mV s−1. b The plot of catalytic peak vs. CySH concentration.
a EIS response of the AgNPs/CNT/rGO/MoO2/Sal-His/GC in different CySH concentrations (1-7) of 1, 3, 7, 13, 20, 30, and 40 nM in 0.1 M PBS (pH 6.0) at frequency of 10 kHz-0.1 Hz. b The corresponding calibration plot of Rct vs. different concentrations of CySH.
a CVs curves of the AgNPs/CNT/rGO/MoO2/Sal-His/GC in different iodate concentrations (1-9) of 0.5, 2, 5, 15, 35, 80, 170, 300, and 700 mM in 0.1 M in PBS (pH 2.0) at a scan rate of 50 mV s-1. b The plot of catalytic peak vs. iodate concentration.
a EIS response of the AgNPs/CNT/rGO/MoO2/Sal-His/GC in different iodate concentrations (1-7) of 5, 15, 30, 50, 70, 100, and 150 nM in 0.1 M PBS (pH 2.0) at the frequency of 10 kHz-0.1 Hz. b The corresponding calibration plot of Rct vs. different concentrations of iodate.
Electrochemical response of various modified electrodes for L-cysteine and iodate.
SEM images of a gold nanoplates synthesized at low pH without NaOH, and b small gold nanoplates synthesized at high pH tuned by NaOH solution. AFM images of: c large and d small nanoplates. The height profile of e large nanoplates, and f small nanoplates.
a, c and e Corresponding TEM, SAED and HRTEM images of large gold nanoplates synthesized at low pH without NaOH. b, d and f Corresponding TEM, SAED and HRTEM images of small gold nanoplates synthesized at high pH tuned by NaOH.
a TEM, b magnified TEM images, and c SAED patterns of the same nanoplate were depicted without tiling the sample holder. d Schematic illustration of the contours with small angles. The incident beam is exactly parallel to the crystal planes at A and directly transmitted, while the orientation of B meets Bragg relationship and diffracted electron beam of B tends, resulting in bright contrast in A and dark contrast in B on the objective aperture. e-l Bright field TEM images of the same nanoplate depicted when X-axis of the sample holder tiled every 5 from -15 to 20.
a SEM image of representative nanoplates. b The zoomed up image of the nanoplate core. c TEM, and d the corresponding SAED images.
Schematic illustration a top view, and b side view of stage induced spiral nanoplate. Two kinds of the stage origin: c dislocation and d tension crack. e SEM image of the small particles attaching at the edge of the nanoplate, as a proof of the edge-based growth process.
Schematic illustration of growth of the multi-layered spiral nanoplate (the upper row) and the corresponding SEM images (the lower row). From left to right are morphologies of different growth stages and gradually matured. Red arrows stand for the growth direction.
LC-ESI/HRMS spectrum of biomedium. The insert column lists specific compositions that may contribute to the biosynthesis of gold nanoplates. For molecules are tested in the negative ion mode (M-H), the measured molecule mass in the insert table is equal to the exact mass deducted the weight of 1 hydrogen atom.
Schematic illustration of the growth of nanoplate, the gold ions have an evolution of nanoclusters, nanoparticles and nanoplates, while the reverse reaction will occur when changing the pH of the solution later.
FT-IR spectra of yeast extract before (spectrum I) and after reaction (spectrum II) in 2000-600 cm–1, the inset shows the extending spectrum in 4000-2800 cm–1.
a Calculated extinction spectra (left) and corresponding charge distribution profiles (right) of the triangular gold nanoplate with 400 nm edges. Four plasmonic resonance modes can be identified in the extinction spectra (arrows), corresponding to the charge distributions profiles of the dipole (1), quadrupole (2), and higher-ordered (3 and 4) modes. b Those for the truncated triangular nanoplate with 80 nm truncated edges. c Those for the truncated triangular nanoplate with 150 nm truncated edges. d Those for the hexagonal nanoplate with 200 nm edges.
SEM images of a and b VN/CNP-5, c and d VN/CNP-20, and e and f VN/CNP-30.
SEM images of VN/CNP-10-20, VN/CNP-10-40, and VN/CNP-10-70.
The TGA and DSC analysis of precursor (Simulation of preparation process of VN/CNPs).
a and b SEM images of V2O5 xerogel; c SEM image, d and e TEM images, and f EDX spectrum of VN/CNP-10.
a The XRD patterns of a V2O5 powder, b VN/CNPs-10, and c V2O5 xerogel. b The TGA and DSC analysis of VN/CNP-10.
XPS spectra of a full scan, and curve fittings of b C 1s, c V 2p3, and d N 1s for VN/CNP-10.
a CV at various scan rates (5-50 mV s-1), and b Galvanostatic charge-discharge curves at various currents (0.5-5 A g-1) of VN/CNP-10.
Comparisons of a CV, b galvanostatic charge-discharge curves, c complex-plane impedance plot, and d cycle life of VN/CNPs (scan rate= 10 mV s-1, current density= 1 A g-1, 2 M KOH aqueous solution).
Comparisons of a CV, b galvanostatic charge-discharge, and c complex-plane impedance plots of VN/CNP-10-20, VN/CNP-10-40, and VN/CNP-10-70 (scan rate=10 mV s-1, current density= 1 A g-1, 2 M KOH aqueous solution).
a CV, and b galvanostatic charge-discharge curves of the hybrid supercapacitor. c Ragone plots of the VN/CNPs symmetric supercapactitor, and the values reported for other SC devices for comparison [25, 57-59], d Green LED was powered by the tandem VN/CNPs-SSCs. (scan rate=10 mV s-1, current density= 1A g-1, 2 M KOH aqueous solution).
Schematic illustration for the preparation of VN/CNPs.
Fabrication scheme of anti-cTnI-PPy-PPa/G-CNTs/GCE bioelectrode.
a SEM image, b EDAX spectrum, c-f elemental map, g-i HRTEM images of PPy-PPa/G-CNTs composite. Insets: (I) SEM image of G-CNTs, (1) SAED pattern of the composite, (2) Atomic scale image of graphene, and (3) SAED pattern of graphene, (4) TEM image of interface between graphene and CNTs at initial growth stage.
a Linear sweep voltammogram of the hybrid bioelectrode at different stages of modification surface. b Corresponding Bode plot.
a Nyquist plot of the bioelectrode before and after incubation with different cTnI concentrations in human serum b Corresponding Bode plot. c Concentration dependent calibration curve of the bioelectrode. d Specificity of the bioelectrode towards cTnI with multiple controls.
EIS characteristic parameters of the bioelectrode on immunoreaction with different concentrations of target cTnI.
Comparison of analytical performance of the bioelectrode with other existing biosensor.
Schematic drawing represents the use of SERS probe GNR techniques comparing to ELISA and fluoresent labelling techniques for detection of adhesion molecules expressed on the surface of macrophage cells (Raw264.7).
a TEM image of GNR/4MBA@anti-ICAM-1. b The average SERS spectrum of GNR/4MBA@anti-ICAM-1) measured using a 785 nm laser excitation with a power of 30 mW and 5 s integration time.
a The average Raman spectra of 4 MBA powder. b The comparison of the SERS spectra of 4 MBA powder (top) and GNR/4MBA@anti-ICAM-1 (bottom). All spectra were measured by a 785 nm laser excitation with a power of 30 mW and 5 s integration time.
SERS spectra detected from Raw264.7 cells treated with LPS for different lengths of time (1, 3, and 5 h). Untreated cells were used as a control and GNR/4MBA@Anti-ICAM-1 particles were used as a target probe. a The SERS spectra were averaged from ~80–235 spectra detected for each condition. b The SERS intensities of the peak at ~1075 cm−1 detected in different treated and untreated cells. Comparisons between group with a control sample were conducted by Tukey-Kramer`s test with significant set at P < 0.05.
a The distribution of SERS signals (yellow dots) detected in untreated Raw264.7 cells and cells treated with LPS at different periods. Raw264.7 cells treated with LPS for 1 h (b), 3 h (c), and 5 h (d). The presence of big yellow dots observed in c and d implies the occurrence of high aggregation degree of particles.
Relative ICAM-1 expression, as measured by ELISA, in Raw264.7 cells after treatment with LPS (1 µg mL-1) for 1, 3, and 5 h or left untreated (control). The * represent significant ICAM-expression compared with a control sample. Comparisons between group were conducted by Tukey-Kramer`s test with significant set at P < 0.05.
a Fluorescent images of untreated Raw264.7 cells (control) or cells treated with LPS (1 µg mL-1) for 1 h (b), 3 h (c), and 5 h (d). Cells were fixed and stained with FITC-ICAM-1 before the expression of ICAM-1 was observed using a fluorescent microscope.
Schematic of metal-dielectric multilayers meta-structure. Here, the gray and brown layers stand for metal (silver) and dielectric, respectively. The multilayers occupy the half-space (z < 0), while the other half is isotropic medium ε1 (z > 0).
Real parts of εx and εz as a function of frequency. The depth ratio dmetal:ddie is set at (a) 2:1 and (b) 1:2. According to the signs of εx and εz, the frequency can be divided into 4 bands as shown in the figure.
Dispersion curves with different background material (in the area with z > 0). The permittivity ε1 for z > 0 is associated with different kinds of materials [15-17]: (a) air, (b) CH3CH2OH, (c) TiO2 and (d) Si.
Each component of wave vector. Corresponding to Fig. 3d, the background material is assumed as ε1 = 13 . a The components of β and k in both multilayers and the free space. b The schematic diagram of electromagnetic field in different frequency ranges. Both the left and right figures represent the bulk mode of electro-magnetic field at low frequency (in region 1) and at high frequency (in region 3), respectively, where the wave vectors k and the Poynting vectors S differ in two regions due to different permittivities. The middle figure stands for the surface wave and the depth skins.
a Propagation length, b skin depth in multilayers, and c skin depth in free space of metal-SPP and multilayers-SPP. The blue and red colors are to mark the frequency range of multilayer-SPPs and metal-SPP, respectively.
The blue area determined by ωupper and ωlower represents the frequency range of multilayers-SPP. The red dashed line marks ωsp for pure metal (silver). Corresponding to the orange dashed line, the inset reveals the dispersion curve of multilayers-SPP as dmetal:ddie = 0.5.
Characterization of ZnO and Sb-ZnO NWs. SEM images of a ZnO and b Sb-ZnO NWs. c EDS mapping images and d EDS spectrum of Sb-ZnO NW. TEM and HRTEM images of e ZnO NW and f Sb-ZnO NW.
a I-V curves of ZnO/Sb-ZnO p-n homojunction in dark (red) and under 365 nm UV light illumination (blue). The energy band diagram of the p-n homojunction in b dark and under c UV light illumination at reverse bias.
a Voltage-time curve of the p-n junction UVD at 0 V bias with 365 nm UV light on and off. b Current-time curve of the p-n junction UVD at reverse bias of −0.1 V with 365 nm UV light on and off.
The enlarged current-time curves of the UVD of a the rise time and b decay time were estimated to be 30 ms.
a Current-time curves of the p-n junction UVD at different reverse bias from −1.0 V to 0 V with the 365 nm UV light on and off. b The photoresponse sensitivity of this UVD as a function of the applied reverse bias.
The mechanism for the formation of double-layer vertically aligned carbon nanotube arrays (VACNTs) through single-step CVD growth was investigated. The growth of the second CNT layer lifts the amorphous carbon coatings on catalyst particles and substrates.
Side-view SEM images of VACNTs obtained by different growth time. a 15 min (868.9 μm in height ). b 30 min (1.6 mm in height). c 30 min (1.9 mm in height and the height of the top layer is 1.5 mm) d 60 min (3.1 mm in height and the height of the top layer is 1.6 mm) e 120 min (4.6 mm in height and the height of the top layer is 1.3 mm) f TEM analysis of CNTs.
Variation of intensity ratio of G/D-band (IG/ID) of Raman spectra along the vertical direction of a double-layer VACNT array.
a SEM image showing the interface between the top layer and the bottom layer of a double-layer VACNT array. b Magnified SEM image of a. c SEM image showing the facture interface between top layer and bottom layer for double-layer VACNTs after pulling test with nippers. d Magnified SEM image of the interface.
Quantitative analysis of C, O, Al, and Fe elements on the interface between the top layer and the bottom layer as characterized by one-line scan electron microprobe technique.
Illustration showing the formation mechanism of double-layer VACNT arrays by single-step CVD method.