Architected Soft Matter and The 4^th Dimension

Stimuli-responsive soft matter promises great potential for autonomous and intelligent engineering systems when precisely manufactured in specific architectures with programmed responses. Emerging pathway to create such dynamic systems involves additive manufacturing of stimuli-responsive and programmable soft matter. This approach has been termed “<i>4D printing”</i>, with the 4th dimension being time. In this talk, additive manufacturing of various soft matter using projection micro-stereolithography (PµSL) is presented. PµSL is a micro 3D printing technique that turns light into a complex 3D structure by utilizing digital light processing (DLP) technology. Combining rapid, versatile, and scalable micro 3D printing technique with various functional soft matter, design principles and mechanics inspired by exquisite motions and morphologies in nature are physically realized. Micro-architectures that can transform and move are demonstrated by programming of dynamic response of various responsive hydrogels. Reconfigurable, deployable, and mechanically tunable lightweight material is created by employing shape memory polymers in mechanical metamaterials. Also presented is printing of liquid crystal elastomers with encoded molecular orientations for programming reversible shape change and soft robotic locomotion.