Principle-based multiphysics simulation for 3D bioprinting systems: modelling inkjet, extrusion, and DLP processes

Among additive manufacturing (AM), 3D inkjet technology, materials extrusion (ME), and digital light processing (DLP), which are from dot and line to face printing, have been extensively investigated for biological and pharmaceutical applications. These techniques are valued for their ability to create customised, complex, drug-laden devices and tissue engineering scaffolds. However, testing new bioinks or filament designs can be both expensive and time-consuming. To this end, numerical simulation offers a useful solution by reducing costs and saving time. Both machine learning (ML) and theory-based models can be used for simulation. ML excels in handling complex data but faces challenges with data availability and overfitting, while theory-based models provide a more interpretable and data-efficient framework. This review explores how theory-based numerical simulation can be used to assess and optimise factors such as bioink printability, technique mechanism, printing parameters, and post-printing outcomes. By using simulation, key parameters can be understood and optimised without performing extensive physical experiments. The review highlights current models and discusses opportunities and challenges in using simulations to enhance the AM process, potentially advancing regenerative medicine and personalised treatments.