Keywords: 4D printing, drug delivery, tissue growth, stem cell
Summary:4D printing is a new field in which materials are first printed into 3D structures with nanoparticles (such as graphene or gold) that can be externally activated to heat up using near infrared (NIR) excitation. As such, the heated nanoparticles change the shape of the 3D printed material on-demand. In this manner, the 4th dimension in 4D printed materials is time. The ability to change material shape after insertion into the body through 4D printing provides much promise for numerous medical applications. For example, 4D printed materials can be used as novel controllable drug delivery devices, change shape to increase pressure in bone defects to improve bone regeneration, and minimize disruption from stem cell culture to cell implantation into the brain. This invited talk will discuss this and many more exciting advances in the field of 4D printing.