Recently, the three-dimensional (3D) printing technique has received much attention for the shape forming and manufacturing. In this work, for the first time, we present the fabrication of inkjet printed 3-diamentional (3D) low cost temperature sensor on a 3D shaped thermoplastic substrate suitable for packaging, flexible electronics and other printed application. The design, fabrication and testing of a 3D printed temperature sensor is presented. The sensor pattern is designed using computer-aided design (CAD) program and fabricated by inkjet printing with a drop-on-demand (DoD) using magnetostrictive inkjet printhead at room temperature. The sensing pattern is printed using commercially available conductive silver nanoparticles ink (AgNPs). The moving speed of 90 mm/min is chosen to print the sensor pattern. The inkjet printed temperature sensor is demonstrated and characterized with good electrical properties, showing a good sensitivity and linearity. The results indicate that the 3D inkjet printing technology may have a great applied potential in sensor fabrication.
Inkjet printings market has been growing for several years. Evaporation rate of droplet was explained relating to the boundary layer and condition near the droplets surface. However, no experimental result has been obtained. This study aims to investigate the boundary layer of ethanol-water mixture droplet and its effect on the evaporation rate by Z-type Schlieren visualization. Single and double droplet were tested and compared in order to identify the effect of the second droplet on the average and instantaneous evaporation rate. Double droplets lifetime was found to be longer than single. It is indicated that larger evaporation region formed on the top of the droplet means higher instantaneous evaporation rate. Boundary layer was found to be larger as ethanols concentration increased. Furthermore, larger evaporation region was found in higher ethanol concentration case and that described faster evaporation found in higher ethanol concentration.