Printed Electrode for High-Performance Bow-Tie Antenna by Photonic Sintering Process

Recently, flexible electronic device technology has evolved beyond curved devices with the development of flexible/stretchable devices that can be crumpled or stretched. Both elasticity and durability are essential for these devices, which should have high-conductivity for antennas and repeatability for sensors. In addition, electronic-skins, which can have a direct impact on the human-body, should be harmless to the human-body and should not be deformed by contact with sweat or organic matter. In this study, PDMS substrates were used to satisfy the above conditions. PDMS is used to fabricate human-friendly, flexible/stretchable substrates, and it has excellent repeat durability characteristics. To improve the adhesion of these PDMS films and electrodes, conductive paste was produced based on PDMS resins of the same properties. In addition, two types of Ag particles were selected as conductive fillers because the electrode characteristics of the antenna application requires excellent conductivity, and conductive paste were produced using flake Ag, which could affect conductivity, and Ag nanoparticles that affect stretchability and repeatability. The paste was applied using a high-efficiency printing technique. The printed electrodes were cured in a thermal oven. For higher conductivity, photonic-sintering was carried out during post-processing. As a result, 1.1117×106 (S/m) had excellent conductivity, performed well in repeated tensile-durability experiments of 30% to 100 times, and produced a bow-tie antenna for the above electrodes. As a result of tensing up to 35% through a Network-Analyzer, there was no performance change in the resonance-frequency or return-loss values, and excellent electrodes were developed that would achieve excellent performance even if they are applied in the sub-frequency area of 5G-antennas in the future.

Pinhole Formation in Printed Electronic Traces Fabricated via Molten Metal Droplet Jetting

The fabrication of printed electronic devices via molten metal droplet jetting has enormous potential in flexible electronic device applications due to the extremely high electrical conductivity and excellent substrate adhesion of printed features. However, large pinholes (which could be detrimental to the feature performance) have been experimentally observed when molten metal droplets of aluminum 4043 alloy are deposited and solidified on a polyimide (PI) substrate. In this study, we have shown that subjecting the polymer substrate to elevated temperature during droplet deposition considerably reduces the number and size of pinholes. The formation mechanism behind the large pinholes is interpreted as the release of the adsorbed/absorbed moisture from the polymer substrate into the solidifying droplet due to the rapid rise in temperature of the substrate upon droplet impact. Through numerical modelling, we have shown that the temperature of the polyimide substrate underneath the deposited droplet exceeds the boiling point of water while the metal droplet is still in liquid state, showing the possibility of water vapor escaping from the substrate and causing pinholes in the solidifying metal.

Aplicación de dispositivos electrónicos para el ahorro de energía eléctrica, en la materia de Instrumentación apoyando la docencia y aprendizaje

The industrial and didactics background, in which we can find the educational institutions, has the neccesity to improve control electronical devices which permit , on one hand, a proactive and productive integral formation of creation and innovation among students, and on the the hand, a flexible electronic device in which they can develop alined projects with up to date requirements,as in the case of automatized systems alined to get an efficient use of electricity. For this case, it is proposed that using these electronical devices, as the Arduino, to create a control sistems that permit to turn on and off the lights or air conditioning systems in a building in an autonomus way to make efficient the electrical consumption. Through an estructurization applied on teaching and learning that improves the asimilation of basical concept's, and to get knowledge on the focus of electromechanical systems that permit a better analysis for taking decisions, searching alternatives and opportunities; redefined and solved problems establishing an armonic relationship with the environment that encompasses inputs,outputs, characteristics and interrelationships among elements permitting to model an interesting electronical system to get a viable solution on scale devices.