Physicochemical parameters that underlie inkjet printing for medical applications

Abstract

One of the most common types of 3D printing technologies is inkjet printing due to its numerous advantages, including low cost, programmability, high resolution, throughput, and speed. Inkjet printers are also capable of fabricating artificial tissues with physiological characteristics similar to those of living tissues. These artificial tissues are used for disease modeling, drug discovery, drug screening, and replacements for diseased or damaged tissues. This paper reviews recent advancements in one of the most common 3D printing technologies, inkjet dispensing. We briefly consider common printing techniques, including fused deposition modeling (FDM), stereolithography (STL), and inkjet printing. We briefly discuss various steps in inkjet printing, including droplet generation, droplet ejection, interaction of droplets on substrates, drying, and solidification. We also discuss various parameters that affect the printing process, including ink properties (e.g., viscosity and surface tension), physical parameters (e.g., internal diameter of printheads), and actuation mechanisms (e.g., piezoelectric actuation and thermal actuation). Through better understanding of common 3D printing technologies and the parameters that influence the printing processes, new types of artificial tissues, disease models, and structures for drug discovery and drug screening may be prepared. This review considers future directions in inkjet printing research that are focused on enhancing the resolution, printability, and uniformity of printed structures.

Recent Advances in 3D Printing for Parenteral Applications

“…, nozzle diameter and nozzle-substrate distance) impact Reynolds, Weber, and Ohnesorge numbers which are dimensionless numbers used to describe printability and droplet formation from inkjet printers [ 50 ]. In addition, inkjet printers rely on actuators, which can include piezoelectric actuation, electromagnetic forces, thermal actuation, and pneumatic pumps to eject ink droplets from the nozzle by overcoming ink surface tension [ 51 ]. Actuator type and its parameters can impact droplet size and overall print quality of constructs.…”

Printed Liquid Crystal Optical Vortex Beam Generators

“…A fabrication technique that might offer a solution to this problem is micron-scale drop-on-demand printing, which has attracted tremendous attention from many different diverse fields including medical, [45][46][47] electronics, [48][49][50][51] agriculture, [52,53] and biology [54,55] due to its high accuracy, compatibility with a wide variety of materials and substrates, and rapid prototyping/fabrication process. It can enable the development of sophisticated 2D patterns and architectures of a range of materials without the need for photomasks.…”

Predicting pharmaceutical inkjet printing outcomes using machine learning

“…Regardless of the deposition mechanism, the optimization of ink characteristics and consequent printing outcomes have been the focus of pharmaceutical inkjet printing research ( Evans et al, 2021 ). Ink properties, such as the viscosity, density, and surface tension, and printing parameters, such as printing speed and nozzle diameter, influence printing outcomes to different arbitrary degrees ( Azizi Machekposhti et al, 2020 ). Undesirable printing results may include clogging, tailing of droplets, and the production of satellite droplets (tiny droplets splattered around the main droplet) ( Azizi Machekposhti et al, 2019 ).…”