Abstract
3D bioprinting has been invented for more than a decade. A disruptive progress is still lacking for the field to significantly move forward. Recently, the invention of 4D printing technology may point a way and hence the birth of 4D bioprinting. However, 4D bioprinting is not well defined and appear to have a few distinct early forms. In this article, a personal perspective on the early forms of 4D bioprinting is presented and a definition for 4D bioprinting is proposed.