We present a capacitive force sensor based on a polydimethylsiloxane (PDMS) film integrated into a printed circuit board (PCB) on a flexible substrate whose layout is defined by inkjet printing. The influence of the dielectric thickness on the sensor behavior is presented. The thinner PDMS film of about 45 μm shows a sensitivity of up to 3 pF/N but poorer dynamic response. The dielectrics with thicknesses above 200 μm show a significantly reduced sensitivity. The best compromise between sensitivity and dynamic response is found for PDMS film of about 100 μm, showing about 1.1 pF/N and less than 15 s of recovery time. This film is integrated into a flexible PCBS including a microcontroller capable of evaluating the sensor. Interconnects of the circuit are defined by silver nanoparticles deposited by inkjet printing. The working principle of the circuit is demonstrated, proving that this simple approach can be used for artificial skin applications.

For luminescent solar concentrators (LSCs), it is important to enhance the fluorescence quantum yield (FQY) and photostability. Our measurements have demonstrated that the addition of silver nanoparticles to dye solution causes broadening of absorption bands, so the spectral range of sunlight absorbed by LSC has increased. Silver nanoparticles (NPs) were characterized by X-ray diffraction (XRD) and UV-Vis absorption spectra. UV-Vis spectrum showed a single peak at 442 nm due to the surface plasmon resonance (SPR). The position of SPR peak exhibited a red shift after the sample was exposed to UV irradiation (unfiltered light). The optical band gap values have a reduction from 2.46 to 2.37 eV after irradiation for 960 minutes. Such reduction in optical band gap may be due to change in particle size calculated using Mie theory. The photostability of organic dyes used was improved after adding silver nanoparticles. The area under fluorescence spectra of dyes with silver NPs increased by 41-31% when compared with identical dye concentrations without silver nanoparticles as a result of interaction of the species with silver NPs.

In the current work, applying a rotating magnetic field (RMF) is an innovative approach to improve the microstructure features and creep resistance of Sn-2.0Ag-2.0Zn (SAZ) alloy. The results revealed that RMF does not change intermetallic compounds (IMCs) constituents furthermore SAZ alloy with applying a magnetic field (SAZ-B) exhibited microstructure refinement and homogeneous distribution of IMCs. Moreover, SAZ-B displayed more creep resistance (∼366%) and greater creep rupture time (∼56.4%) than those of SAZ alloy. These results have great implications in improving the alloy’s performance for industrial applications.

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We report on the morphological, electrical and optical characteristics of Carbon nanotube (CNT) films on different transparent substrates, obtained using spray deposition. The effect of different substrate materials on the characteristics of spayed CNT films with varying thickness is investigated. While film morphology is shown to depend on the underlying surface characteristics, no significant changes in work function are observed. These results are compared to films deposited onto flexile substrates. Further, time-resolved THz spectroscopy reveals picosecond transient photoconductivity dynamics in sprayed CNT films on flexible PET substrates.

Recently, the application of the magnetic field during the solidification process of alloys has become of great interest, owing to its ability to enhance microstructures. Hence, the present work aims to study the impact of a rotating magnetic field on the microstructure, thermal, and creep properties of the Sn–2.0Ag–0.5Cu (SAC205) alloy during solidification. Results demonstrated that applying a rotary magnetic field homogenized the distribution of intermetallic compounds and improved the microstructure. Additionally, the magnetic field diminished undercooling from 22.5 oC to 11.4 oC, indicating that the magnetic field is very useful in enhancing the microstructure and the alloy’s reliability. The pasty range values for SAC205 and SAC205-B were 7.2 oC and 8.6 oC lower than 11.0 oC for lead-tin, leading to a reduction of the alloy porosity. The SAC205-B alloy exhibited the longest creep rupture time of 158.5% compared to the SAC205. The n values of SAC205-B were higher than those of SAC205. Consequently, the SAC205-B alloy displayed the highest creep resistance and lowest creep rate (28.53%) compared to the SAC205. The Q values were 51.2 and 67.5 kJ/mol for SAC205 and SAC205-B, respectively, controlled by pipe diffusion. This research will provide practical advice for the manufacture of the solder alloy.

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