The fabrication and characterization of a temperature sensor on flexible poly(ethylene terephthalate) (PET) substrate is discussed. The device was printed by drop-on-demand (DOD) electrohydrodynamic (EHD) Patterning method using silver nanoparticles ink on a roll-to-roll (R2R) system on a mass scale. EHD patterning was performed at atmospheric pressure and room temperature in a single step. The ink viscosity was 300 cps and it contained 55 wt % of silver nanoparticles. The parameters for printing head speed, and DOD were optimized to create connected lines. The printed temperature sensor has the resistivity of 25.35 µΩ·cm and the temperature coefficient of resistance (TCR) is 0.0007687 °C−1. The micro sensor can be applied to many applications to measure temperature accurately of flat or curved surfaces.

This paper presents the electrospray deposition of solution-based ZnO nanoparticles. Transparent thin film transistors in active matrix displays have become the most interested research area. Electrospray assures direct deposition by eliminating etching steps required after deposition by other techniques. Uniform layers of minimum thickness 87 nm on glass and 356 nm on polyimide using electrospray experiment is achieved. Contact angle analyzer has been used for finding properties like wetting energy, spreading coefficient and work of adhesion of the ink on glass and polyimide substrates. All experiments were performed in ambient conditions.

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Conventional surface acoustic wave - electrostatic deposition (SAW-ED) technology is struggling to compete with other thin film fabrication technologies because of its limitation in atomizing high density solutions or solutions with strong inter-particle bonding that requires very high frequency (100 MHz) and power. In this study, a hybrid surface acoustic wave - electrohydrodynamic atomization (SAW-EHDA) system has been introduced to overcome this problem by integrating EHDA with SAW to achieve the deposition of different types of conductive inks at lower frequency (19.8 MHZ) and power. Three materials, Poly [2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV), Zinc Oxide (ZnO), and Poly(3, 4-ethylenedioxythiophene):Polystyrene Sulfonate (PEDOT:PSS) have been successfully deposited as thin films through the hybrid SAW-EHDA. The films showed good morphological, chemical, electrical, and optical characteristics. To further evaluate the characteristics of deposited films, a humidity sensor was fabricated with active layer of PEDOT:PSS deposited using the SAW-EHDA system. The response of sensor was outstanding and much better when compared to similar sensors fabricated using other manufacturing techniques. The results of the device and the films’ characteristics suggest that the hybrid SAW-EHDA technology has high potential to efficiently produce wide variety of thin films and thus predict its promising future in certain areas of printed electronics.

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