Jetting droplets on semi-solid substrate for biological applications

A droplet exits the inkjet orifice during the jetting phase and subsequently lands on a substrate in the impact phase. This article highlights the journey of a jetted ink, beginning with droplet formation followed by drop impact on varying substrates such as solid, liquid and semi-solid. In bioprinting where the viability of cells plays a pivotal role in the success of bioprinted constructs, the key is to implement strategies that reduce cell deformation during and after the ejection of cell-laden droplets in the droplet-based printing processes such as inkjet bioprinting. The event post impact (i.e. spreading, evaporation and absorption) lie key factors in improving jetted cells while also tuning hydrogel substrates properties that support cell growth. With various strategies and approaches in inkjet printing, there lies opportunities through designing materials and innovative platforms using inkjet printing for biological studies.