Precise dot inkjet printing thought multifactorial statistical optimization of the piezoelectric actuator waveform

Abstract

InkJet printing is a technique that in the last decades has attracted the attention of the scientific community because it allows producing customized patterns with a variety of inks and substrates, making it suitablemethod for the production of flexible circuits. However, the optimization of this technique is still problematic due to a large number of process variables. Among them the modification of the waveform parameters of the piezoelectric actuator that allows the ejections of the ink can be effective in tuning the printing quality. This work reports a study by a statistical method, namely Design of Experiments (DOE), to optimize the inkjet printing parameters for a nanoparticle-based silver (Ag) ink. This method showed the interplay of the waveform parameters into the definition of optimal drop reproducibility and the achievement of the optimal resolution. In particular, it is shown that mixed terms of the model have a statistical significance and therefore the proposed multifactorial approach provides a benefit in the optimization with respect to the more commonly used one-factor-at-a-time models (OFAT). For the first time, empirical equations have been reported within the corresponding 95% confidence intervals. These equations can be used as a tool to directly tune the properties of the printed dot by modifying the waveform parameters. As case study, we proposed the combinations of a commercial Ag nanoparticles ink with Kapton, a commonly used substrate for flexible electronics.

Preparation and characterization of a soluble eggshell membrane/agarose composite scaffold with possible applications in cartilage regeneration

“…To avoid the modification of the morphology the hydrogels were rapidly frozen using liquid nitrogen to reduce the ice crystal dimension and not compromise the structure formed by the gels, then a freeze‐drying procedure was conducted for 2 days at 35°C. The pore size was then evaluated by image analysis conducted using the ImageJ (Schneider et al., 2012) following a previous developed methodology (Bucciarelli, Adami et al., 2020; Bucciarelli, Muthukumar et al., 2019; Bucciarelli, Reddy Chandraiahgari et al., 2020) and shown in Figure 1. Briefly, three images for each scaffold were collected by SEM, a color threshold was then applied to isolate the pores from the scaffold walls, subsequently the pores perimeter and the inner area were calculated.…”

Imaging the Morphological Structure of Silk Fibroin Constructs through Fluorescence Energy Transfer and Confocal Microscopy

“…The produced fibers might find application as an optical sensor whenever an interaction with biological tissues is required [31,36] as for example in the case of wound healing [37,38] or for visualization purposes both in vitro and in vivo [39,40]. In addition, the proposed methods could be easily coupled with other additive manufacturing techniques [41,42] to produce 3D constructs [43]. Figure 6.…”

Optimization of a Low-Power Chemoresistive Gas Sensor: Predictive Thermal Modelling and Mechanical Failure Analysis

“…A statistical method was used to cross-correlate the results obtained from the thermal predictive model and the mechanical failure analysis and to define a comprehensive model for tuning future sensor layouts to the required performance. The entire statistical analysis was done using the programming language R [ 57 ] following the statistical strategy described in previous works [ 58 , 59 , 60 , 61 ]. An initial comparison by verifying the presence of a significant difference among the various groups was performed by using the analysis of variance (ANOVA) and was followed by a Tukey multi-comparison test.…”