Strain sensors have spread at present times, and their electrical resistance has been interpreted. In reality, the use of strain sensors has broadened the reach of technology and allowed us to track changes in the environment in various ways. In recent years, due to their distinctive properties, films based on advanced carbon nanomaterials have started applying sophistication sensing. The strength of the tailored material has been obtained in addition to the various functions applied to these nanomaterials due to the particular structure of the nanomaterials. A prime catalyst for developing nanoscale sensors was this excellent feature. Carbon nanomaterials-based films have been increasing widely due to the excellent properties of nanocomposite-based films for sensing applications (piezoelectric application). There is also an instinctive structure of nanomaterials so that the material is high. Carbon nanomaterials such as graphene are now an excellent alternative for the production of sensors for thermal, electric and mechanical reading.

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The PVA-G-Ag nanocomposite have been synthesized effectively by pulsed laser ablation liquid (PLAL) as a considered to be environmentally friendly and free of residues from chemical reactions. The high excellence silver plate (99.99%) and graphite plate (99.99%) was immersed in the polyvinyl alcohol (PVA) solution and irradiated with the Nd-YAG laser at wavelength 1064 nm, power 160 mJ for the silver plate and 80mJ for graphite plate, reiteration rate 6 Hz, 10 ns pulse width and 300 pules for graphite plate and 700 pulse for silver plate. The pure of PVA, PVA-Graphene and PVA-Graphene-Ag nanocomposite were investigated using UV-VIS spectroscopy, FTIR and SEM. The absorption spectra of PVA-Graphene-Ag nanocomposite show the presence of two peaks one 0.4 at 272 and second 0.47 at 403 nm. The optical energy gap (Eg) decreased from 5eV of a pure PVA to 4.6eV of a PVA-G-Ag for indirect allowed transition and therefore, decreased from 4.4eV of a pure PVA to 4.1eV of a PVA-G-Ag for indirect forbidden transition. The transmittance and absorption coefficient have been determined. The SEM images confirmed that homogenous composite without aggregation of the components. The average size of nanoparticles of GNPs and AgNPs for PVA-G and PVA-G-Ag nanocomposite was 130 and 115 nm respectively. The FTIR has demonstrated that the connection between the graphene, silver and polymer network was enough to have stable nanocomposite. This investigation demonstrates that the pulse laser ablation decent instrument to decorated metals on the graphene with the presence of the polymer.

In this work, zinc oxide (ZnO) and Al-doped ZnO (0.002, 0.004, and 0.006 wt.%) thin films were prepared by thermal evaporation technique with the thickness of about 125 nm. The X-ray diffraction (XRD) results showed that the prepared films were crystalline with a hexagonal wurtzite structure and preferential orientation in the (002) direction. The crystallite size increased with the increasing of Al doping. Atomic force microscopy (AFM) confirmed that the films grown by this technique had a good homogeneous surface. The roughness average, root mean square value, and the average grain diameter increased with the increasing of Al doping. The optical properties results showed that the transmittance increased with the increasing of Al doping, while the absorbance decreased. The pure and Al-doped ZnO thin films allowed direct energy gap (E g ) that was increased from 3.50 to 3.80 eV with the increasing of Al doping. The electrical properties of the films were studied, and it was found that all the prepared thin films were n-type and the mobility (µ) decreased with the increasing of Al doping. Current-voltage (I-V) characteristics showed that the highest efficiency was 3.64% with V oc as of 2.8 V, I sc as of 3.5 mA/cm 2 and F.F of 0.371 at the intensity of P =100 mW/cm 2 ..

Nanostructured pure and Indium doped iron oxide thin films were deposited via spray pyrolysis technique (SPT). The effects of Indium (2 and % 4) concentration was studied. X-ray diffraction patterns disclosed that Fe2O3 films have a rhombohedral crystalline of α-Fe2O3 phase and their crystallite size was vary from (12.13 – 13.84) nm with Indium content. The strain(%) parameter decrease from 28.57 to 25.04, AFM images of films show changes in morphology with decreased in surface roughness from 2.75 nm to 1.7 nm with Indium 4% doping, The 3-D images and grain size distribution are illustrated that they exhibit spherical nano-grains ranged from 72.72 nm for pure Indium to 51.22 nm for 4% Indium doped Fe2O3. The transmittance decreases with increasing Indium concentration. The bandgap energy of Fe2O3 thin film was 2.75 eV and it decreases to 2.55 eV for Fe2O3:4% In.

In this study, many samples have been synthesized by using solution casting technique with different additive content of Chromium oxide nanoparticle (Cr2O3NPs), poly vinylalcohol (PVA) and polyethylene glycol (PEG). The UV-Vis. spectrophotometer used to record the absorbance spectrum in the range of (200-800) nm. The absorption of UV waves is improved while the transmittance is reduced when Cr2O3 NPs were added to the polymeric system which are useful for a number of applications including low-cost UV protection and solar radiation shield. When Cr2O3 NPs concentrations increased, the optical energy gap for indirect transition (allowed and forbidden) was decreased. Furthermore, all the optical constant has been improved.

The dielectric characteristics of PVA/PEG/In2O3 nanostructures were tested to use in various electric nanodevices. The films of nanostructures of PVA/PEG/In2O3 were synthesized by casting solution technique. The dielectric characters of PVA/PEG/In2O3 nanostructures were determined. Results expressed that the dielectric parameters of PVA/PEG were rise with rise in the In2O3 NPs ratio. The performance of ε', ε" and σAC with frequency illustrated that the ε' and ε" reduced whereas the σAC rises with rise in frequency. The final results demonstrated the PVA/PEG/In2O3 nanostructures may be suitable in various electrical nanodevices.

In this study, casting technique were used to fabricate of PEG/Fe2O3 nanostructures with variant content of Fe2O3 NPs to employ in different optical fields. The results showed that the absorbance of PEG increases as the concentrations of Fe2O3 nanoparticles increase while the transmittance and energy gap of PEG decrease with increase concentrations of Fe2O3 NPs. The optical factors of PEG/Fe2O3 nanocomposites are enhanced with adding of the Fe2O3 NPs content. The optical characteristics results of the PEG/Fe2O3 nanocomposites proved that may be employed in optoelectronic detector.