Physics problems in bio or bioinspired additive manufacturing

Additive manufacturing,also known as three-dimensional(3D)printing,has attracted increasing attention due to the innovations in materials science and manufacturing over recent decades[1].Recently,innovations in biocompatible materials and biology have enabled the extension of 3D printing techniques into bioadditive manufacturing,which focuses on the fabrication of 3D engineered native-like tis-sues/organs[2].Currently,bioadditive manufacturing tech-nologies can be categorized into inkjet-based bioprinting,microextrusion-based bioprinting,digital light processing(DLP)bioprinting,electric field-assisted bioprinting,and fused deposition modeling(FDM),to name a few[3,4](Fig.1).Artificial tissues and organs with delicate structures,such as the heart[5]and liver[6],have been successfully fab-ricated using various bioadditive manufacturing techniques.Bioadditive manufacturing has also been involved in drug screening due to its high deposition accuracy[7].However,despite continuous improvements in printing techniques and the broader choice of materials for 3D bioprinting,it remains challenging for 3D bioprinted constructs to be deemed as sub-stitutes for native tissues and organs at the present moment due to their limited printing reliability and functionality[8].