Porcupines Inspire 4D-Printed Microneedles that Could Replace Shots

New 4D-printed microneedles could one day eliminate the need for painful hypodermic needles to deliver shots, inject drugs, and get blood samples, according to Rutgers University  researchers. They found inspiration in scaled quills of porcupines, microhooks of parasites, and barbed stingers of honeybees to create the innovation. The microneedle array has backward-facing barbs that interlock with tissue when inserted, enhancing adhesion. While 3D printing builds objects layer by layer, 4D goes further with smart materials programmed to change shape after printing (and time is the fourth dimension that allows materials to morph into new shapes). “We think our 4D-printed microneedle array will allow for more robust and sustained use of minimally invasive, pain-free, and easy-to-use microneedles for delivering drugs, healing wounds, biosensing, and other soft tissue applications,” says researcher Howon Lee.